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Treatment of a patient with corns and tinea pedis
OPT ONS IN P ACT CE FEATURE EDITOR: Maureen Hanlon, RN, MN, CETN
Q
ptions in Practice presents different m a n a g e m e n t approaches to the same clinical situation. You are invited to submit a brief case description, including the specialty nursing care provided, and several glossy, color photographs of the clinical situation. The case material will then be sent to another wound, ostomy, or c o n t i n e n c e care nurse, who will also address mana g e m e n t concerns. Alternative solutions to difficult wound, ostomy, or incontinence clinical situations will be pubiished.
TREATMENT OF A PATIENT WITH CORNS AND TINEA PEDIS A 66-year-old man was referred to our nurse-managed foot-and-wound-care clinic for routine foot care. His medical history was significant for a 30-year history of type II non-insulin-dependent diabetes mellitus controlled by oral agents and diet. In addition, he experienced multiple critical events over the past year, including an acute episode of pulmonary edema leading to myocardial infarction, coronary artery angioplasty, and right femoral popliteal bypass surgery, followed by a second myocardial infarction complicated by acute liver failure. His social history was remarkable for a 50-year habit of smoking one to two packs of cigarettes per day and occupational-related chronic venous stasis disease. Unfortunately, his job required that he stand for prolonged periods, typically varying from 10 to 12 hours per day. The patient's functional status was also limited. He was unable to reach his lower extremities and feet because of chronic shortness of breath. Consequently, foot and lower extremity care had to be performed by his wife or at our clinic.
Vascular Assessment Vascular assessment of the feet and lower extremities revealed significant abnormalities. The right dorsalis pedis and posterior tibial pulses were palpable but greatly diminished. The left dorsalis pedis and posterior tibial pulses were nonpalpable and barely audible on Doppler ultrasound.
The left foot was cold to touch and violaceous when placed in the dependent position. The limb was observed to blanche with elevation, demonstrating further evidence of arterial insufficiency. When compared with the left foot, the right foot was warmer and exhibited greater rubor.
Neurologic Assessment Sensory nerve testing of the feet was performed, including protective, vibratory, and proprioceptive assessments. A quantitative and reliable standard to use when testing for protective sensation is the 10-gram, (No. 5.07) Semmes-Weinstein calibrated n y l o n monofilament. 1 The ability to perceive the 10-gram monofilament indicates that the patient has protective pressure sensation in the foot. The following procedure is r e c o m m e n d e d when using the monofilament to evaluate sensation in a foot. The examiner should begin the evaluation by touching his or her hand with the monofilament, followed by touching the patient's hand, to provide reassurance that the filament is not sharp and that examination will not hurt. The examiner should limit distractions such as noise in the room and avoid touching other areas on the lower extremity. The patient is instructed to close the eyes, and the examiner begins the assessment by testing the fat pad on the plantar surface of the first, third, and fifth toes, followed by assessment of the area over the first, third, and fifth metatarsal heads. Care should be taken to avoid any callused areas. The clinical examination continues, moving to the midfoot and one area on the heel. 2-4 We prefer to use a pen-type 10-gram, No. 5.07 monofilament (North Coast SemmesWeinstein monofilament; North Coast Medical, Inc., San Jose, Calif.) In this case, sensory testing revealed a lack of protective sensation. This sensory deficit increased the risk for foot injury because the patient was unable to perceive light touch or light pressure applied to the plantar surface of the foot. Detection of this deficit was particularly important because prolonged exposure to pressure from a foreign body in the shoe, or an unrelieved and repetitive shearing or friction, could lead to injury, ulceration,
Karen Lukacs, RNCS, MSN, CWCN, is a Gerontological Clinical Nurse Specialist in the Department of Neurology of the Medical University of South Carolina, Charleston. Teresa Kelechi, RNCS, MSN, CWCN, is a Gerontological Clinical Nurse Specialist at the Center for the Study of Aging, Medical University of South Carolina, Charleston. Reprint requests: Karen Lukacs, RNCS, MSN, CWCN, Department of Neurology, MUSC, 171 Ashley Ave., Charleston, SC 29425.
J WOCN 1998;25:169-74. Copyright @ 1998by the Wound, Ostorny and Continence Nurses Society.
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Figure 1. Corn on second toe of right foot, hammer toes, and bunions.
first felt and when it stops. Assessment of the MTPJ is followed by testing of the lateral malleolus and medial malleolus. Vibration is a function of large (myelinated) nerve fibers. It is mildly diminished with normal aging, but significant defects are associated with peripheral polyneuropathy in a person with diabetes mellitus, central nervous system disorders, chronic alcohol abuse, or with exposure to toxins. 8 The patient should stop feeling the sensation at approximately the same time that the examiner no longer feels the vibration in the tuning fork. Findings should be documented as present, decreased, or absent. 8,9 In this case, the patient's vibratory sensation was assessed as absent. A third test for peripheral nerve function, position sense, or proprioception also was assessed. Position sense is tested by having the patient close the eyes while the examiner firmly grasps the great toe in the neutral (straight) position. The patient is asked to describe in which position the toe is during gentle manipulation into the following positions: (1) dorsiflexion, (2) plantar flexion, (3) return to neutral position. Findings are documented as present or absent. 8'9In this patient, position sense was preserved bilaterally.
Structural Assessment
Figure 2. Corn on fifth toe, hammer toes. infection, or amputation if not treated promptlyY Distal vibratory sensation was tested using a 128-Hz tuning fork. To administer this test, the patient is instructed to close the eyes. The clinician grasps the stem of the fork and taps the prongs against the hand, causing it to vibrate briskly. The examiner then places his or her index finger over the patient's metatarsophalangeal joint (MTPJ), located on the dorsum of the foot at the base of the first toe. The stem of the tuning fork is placed on the index finger. The patient is asked to report when the sensation or vibration is
Structurally, the feet were characterized by loss of the plantar fat pads (the dense subcutaneous tissue that absorbs shock and naturally decreases with age). The metatarsal heads were easily palpable and prominent. Bilateral bunions and hallux valgus deformities (deviation of the proximal great toe medially at the MTPJ causing the distal toe to deviate laterally) were present. The patient had rigid flexion contractures of the second, third, and fourth toes bilaterally (hammer toes), with small red area s on the proximal interphalangeal joint (PIPJ). A corn on the right, second PIPJ was noted (Figure 1). He also had a painful hard corn (heloma durum) on the lateral surface of the right fifth toe (Figure 2). Corns are hyperkeratoses and represent an accumulation of dehydrated epidermal cells that are often highly concentrated in the center of the lesion and gradually thinning at its periphery. 1°,11 This type of corn has a characteristic hard "built-up" center, with easily differentiated layers of epidermis. Corns most commonly occur as a result of abnormal
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p r e s s u r e , shearing, or frictional forces on s k i n of n o r m a l t h i c k n e s s . In c o n t r a s t , calluses are c a u s e d b y the s a m e conditions b u t arise on the p l a n t a r a n d l a t e r a l or m e d i a l surfaces of the f o o t - - s k i n that has a thicker e p i d e r m i s . This p a t i e n t ' s structural deformities were probably a t t r i b u t a b l e to the p r o l o n g e d s t a n d i n g r e q u i r e d b y his occupation, to his h i s t o r y of w e a r i n g n o n s u p p o r t i v e n a r r o w shoes, a n d to his diabetic p o t y n e u r o p a t h i e s .
Skin Assessment The skin b e l o w the knees e x h i b i t e d a dry, cracked, a n d flaky a p p e a r a n c e , w i t h h y p e r p i g m e n t a t i o n of the e p i d e r m i s at the ankle flare region. This p r o b a b l y repres e n t s a s e q u e l a of his c h r o n i c v e n o u s insufficiency. There w a s a dry, u n i f o r m scaling a p p e a r a n c e of the skin o v e r the f o r e f o o t a n d p l a n t a r surfaces. The skin b e t w e e n the first a n d s e c o n d toes bilate r a l l y h a d m a c e r a t i o n of the e p i d e r m i s a n d e x h i b i t e d a strong, foul odor. After debris from b e t w e e n the toes was cleaned, the skin retained its macerated and whitish a p p e a r a n c e , a l t h o u g h small p i n k a n d r e d fissures w e r e o b s e r v e d u n d e r this mace r a t e d skin. The p a t i e n t c o m p l a i n e d of occasional itchiness on the b o t t o m of the foot. H e s t a t e d that he h a d a l w a y s h a d " a t h l e t e ' s foot" a n d h a d b e e n t r e a t e d b y a d e r m a t o l o g i s t for f u n g a l infections in the past. Karen Lukacs, R N C S , M S N , C W C N : The i n i t i a l g o a l of s k i n care for this p a tient w a s to t r e a t his corns in an effort to r e d u c e the r i s k of u l c e r a t i o n or infect i o n of the u n d e r l y i n g a n d a d j a c e n t tissue. T r e a t m e n t of corns r e q u i r e s d e t e r m i n a t i o n of the causative factors. For this p a t i e n t , the corns w e r e p r i m a r i l y a consequence of the anatomical and functional c h a n g e of the f o r e f o o t a n d his i l l - f i t t i n g f o o t w e a r . His f o o t w e a r w a s t h o r o u g h l y i n s p e c t e d to d e t e r m i n e w h e t h e r his shoes or s o c k s w e r e c a u s i n g excessive p r e s s u r e on the a r e a s of c o r n d e v e l o p m e n t . Bec a u s e this p a t i e n t ' s corns w e r e on the t o p of the toe c o n t r a c t u r e ( h a m m e r toe) a n d on the lateral fifth toe, w e c o n c l u d e d t h a t the corns d e v e l o p e d as a r e s u l t of excessive p r e s s u r e a g a i n s t the sides a n d t o p of the shoe. W h e n i n s p e c t i n g footw e a r , w e r e c o m m e n d p a l p a t i n g the int e r i o r of the s h o e w i t h a g l o v e d h a n d to d e t e c t a n y r o u g h or U n e v e n a r e a s a n d to identify a n y foreign bodies. The h e i g h t of the toe b o x a n d the s h a p e of the shoe
it
Figure 3, A-B, Forefoot test. at the f o r e f o o t is also p a l p a t e d . The heel a n d sole of the shoe are t h e n i n s p e c t e d to d e t e r m i n e w h e t h e r there is a p a r t i c u l a r w e a r p a t t e r n i n d i c a t i n g an a l t e r e d gait such as that c a u s e d b y i n v e r s i o n or evers i o n of the foot. A f t e r a s s e s s m e n t of the p a t i e n t ' s footw e a r , a forefoot test is c o m p l e t e d . The p a t i e n t is a s k e d to s t a n d w i t h o u t footwear on a piece of 11x 14-inch white paper, a n d the o u t l i n e of the foot is t r a c e d w i t h a b l a c k m a r k e r (Figure 3,A). The shoe is then p l a c e d over the outline of the traced
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Figure 4. Tinea pedis, plantar surface with scaling. foot (Figure 3,B). A n y p o r t i o n of the tracing that falls o u t s i d e the s h o e ' s b o r d e r s provides an assessment of whether the foot m u s t be "squeezed" to fit the shoe. We use this test to identify excessive lateral pressure on the first a n d fifth toes a n d deform i t y of the toes as t h e y are forced into a n a r r o w shoe. In this case, the p a t i e n t ' s shoes were f o u n d to be n a r r o w and short, a n d t h e y were b e l i e v e d to contribute to his corns because they created excessive p r e s s u r e against the tops of the toes a n d the lateral aspect of the fifth toe.
Management of Corns The t r e a t m e n t of a corn is p r i m a r i l y d e t e r m i n e d b y its thickness, the a m o u n t of discomfort it p r o d u c e s , a n d the p a t i e n t or caregiver's abilities to follow a specific t r e a t m e n t regimen, l°,n Initially, the corn on this p a t i e n t ' s fifth toe r e q u i r e d s h a r p d e b r i d e m e n t (paring) of the h a r d outer layers a n d conservative care (buffing a n d p a d d i n g ) of the corn on the h a m m e r toe. The corn on the fifth toe was p a r e d using the following supplies: a basin, soap, water, towels, gloves, No. 3 scalpel h a n d l e , No. 17 r o u n d p o d i a t r y scalpel b l a d e or No. 88 chisel b l a d e a n d a p p r o p r i a t e h a n d l e , alcohol pads, gauze, and p o s t d e b r i d e m e n t p a d d i n g of choice. The affected area of the foot was washed with soap and
w a t e r a n d g e n t l y d r i e d . The p a t i e n t ' s foot w a s g r a s p e d in the n o n d o m i n a n t h a n d , a n d the toe w a s s e c u r e d w i t h the e x a m i n e r ' s fingers. The corn w a s d e b r i d ed using a "layer-to-layer" technique. Initially, small, thin l a y e r s w e r e p a r e d from the t o p u n t i l the b a s e of the corn w a s reached. We t o o k care n o t to exert excessive p r e s s u r e on the scalpel h a n d l e or the blade, and we avoided using a sawing m o t i o n d u r i n g p a r i n g . If a corn is p a r ticularly hard, it can be softened b y soaking in a b a s i n of w a r m w a t e r (98 ° F) for 3 to 5 m i n u t e s . A w a r m w e t w a s h c l o t h also can be p l a c e d over the corn for the s a m e a m o u n t of t i m e to p r o m o t e s o f t e n i n g . P a r i n g is c o n t i n u e d until it has a soft a n d s m o o t h a p p e a r a n c e a n d is level w i t h the s u r r o u n d i n g skin. P a r i n g is d i s c o n t i n u e d before this point if the corn becomes "pink" in color. After p a r i n g is c o m p l e t e d , the a r e a is w i p e d w i t h a m o i s t e n e d saline g a u z e p a d or alcohol p a d to r e m o v e a n y debris. We c o m p l e t e d sharp d e b r i d e m e n t of the outer layers of the corn on the fifth toe, a n d w e t a u g h t the p a t i e n t a n d his wife h o w to buff the corns on his h a m m e r toe. The buffing a n d p a d d i n g p r o c e d u r e require the following supplies: (1) a handheld acrylic nail file, (2) gloves, a n d (3) alcohol p a d s or g a u z e p a d s m o i s t e n e d w i t h saline. The p a t i e n t or family m e m b e r is t a u g h t to buff the corn b y first securing the toe with the nondominant hand, stretching a n d stabilizing the skin s u r r o u n d i n g the corn, a n d gently filing the corn in one d i r e c t i o n only. The p a t i e n t is t a u g h t to a v o i d using a s a w i n g motion; instead, he is i n s t r u c t e d to file u n t i l t h e a r e a has b e c o m e s m o o t h a n d e v e n w i t h the s u r r o u n d i n g skin. The p a t i e n t is a d v i s e d that the corn will become s o m e w h a t translucent a n d p i n k as the hyperkeratotic skin is buffed away. After this process, the skin is cleansed w i t h a m o i s t e n e d saline gauze p a d or alcohol p a d to ensure it is smooth. P a d d i n g t h e s e t y p e s of corns can be a c c o m p l i s h e d w i t h a v a r i e t y of p r o d u c t s , such as Dr. Scholl's L a m b s w o o l (Shering Plough, Memphis, Tenn.) or digit gel p a d s (Silipos, N i a g a r a Falls, N.Y.). The l a m b s w o o l is s e p a r a t e d into s t r a n d s that are a p p r o x i m a t e l y 5 to 8 inches long (forefoot sized) a n d ¼ to ½ inch wide. It is then w o v e n b e t w e e n a n d t h e n over the h a m m e r toes so that it covers the corn a n d d e c r e a s e s p r e s s u r e a n d friction f r o m the shoes. The d i g i t gel p a d s w i l l r e l i e v e
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pressure and friction over the digit. In addition, they are impregnated with silicone and mineral oil and designed to soften the underlying corn during wear. Both products should be used when footwear is worn. They do not need to be worn at night. Teresa Kelechi, MSN, RNCS, CWCN: Another goal for this patient was to alleviate the symptoms associated with the fungal infection of his feet (tinea pedis), and to improve the integrity of the skin by treating the inflammation, fissures, and peeling. Tinea pedis is the most common form of dermatophytosis, a fungal infection acquired from the soil, animals, and other humans. 12The most common transmission vector is other infected people, and those who frequent sports facilities, pools, and communal leisure facilities are also at risk. 13Contributing factors include warmth and high humidity, with constant occlusion of the skin surface, functional limitations that inhibit self-care, and chronic conditions that affect the immune system such as HIV or diabetes mellitus. D e r m a t o p h y t e s invade, infect, and persist in the stratum corneum and rarely penetrate below the surface of the epidermis or its appendages. The skin responds to this superficial infection by increased proliferation, which leads to scaling and epidermal thickening.~2 In this patient, scales were predominate on the plantar and medial surfaces of the foot (Figures 4 and 5). This presentation is called a moccasin-type infection, most likely caused by the dermatophyte Trichophy-
Figure 5. Tinea pedis with scales on right great toe.
ton rubrum. The patient exhibited symptoms of tinea pedis, including itching, scaling, and small breaks in the skin integrity. On close inspection, the skin between the first and second toes were remarkable for a bilateral whitish-appearing maceration with fissures. Interdigital toe-web infections usually start as a dermatophyte infection (Trichophyton rubrum and Trichophyton mentagrophytes), but various bacterial species and (rarely) Candida may complicate this infection. Scaling is the initial feature and, when the bacteria proliferate, maceration occurs (Figure 6). The terms dermatophytosis simplex and dermatophytosis complex have been proposed to address two forms of interdigital infection. Dermatophytosis simplex is characterized by scaling and fissures, whereas dermato-
Figure 6. Maceration of toe w e b space. phytosis complex causes maceration and exudate. 14 This patient had features of derrnatophytosis complex. The treatment of these infections tends to be empirically based, but greater diagnostic accuracy can be obtained when clinical diagnosis is verified by laboratory tests. A specimen can be obtained by scraping the active border or edge of a scale, lesion, or macerated area.
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The material is placed on a slide and a 10% to 15% potassium hydroxide (KOH) solution is added, along with a fungal stain. A positive KOH will show multiple septate hyphae under microscopic examination. 15 Trichophyton rubrum and Trichophyton mentagrophytes had been diagnosed previously in this patient by his dermatologist. His treatment was affected by several factors. His medical history revealed a recent episode of severe liver dysfunction; therefore, oral antifungal therapy was not an option because m a n y oral agents can be hepatotoxic. 14As an alternative, a topical antifungal agent (Lamisil Cream 1%) was selected. Unfortunately, the patient was not capable of reaching his own feet because of chronic shortness of breath. Therefore, his caregiver was instructed to wash his feet daily, paying particular attention to drying thoroughly between the toes. After the feet were dry, she was instructed to apply the cream twice each day to the plantar surfaces of his feet and toe web spaces until clinical signs and symptoms significantly improved, usually by day 7 of treatment. Topical therapy was recommended for a minimum of I week, but not to exceed 4 weeks. His condition began to improve on day 5 of therapy but, because of his long history of infection, he required approximately 25 days of treatment. Treatment of his dermatophytosis complex also required a broad-spectrum antibacterial agent. The dermatologist had instructed the patient to apply gentian violet, a tincture of dye. He did not like the resultant bluish purple skin staining because his preferred footwear was sandals (against our advice). Therefore, the tincture was discontinued, and his wife was taught to apply a triple antibiotic ointment twice daily. After treatment of the fungal infection, the patient and his wife were taught to care for the skin of the feet. They were instructed to bathe the feet with tepid water (94 ° F) and a standard commercial bar or liquid soap and to avoid soaking the feet. Soaking can be detrimental to the skin when it leads to overhydration, trapping of water between the toes, and maceration of the toe web spaces. Soaking also places additional physiological demands on a compromised vascular status if the temperature of the water is too high.5 After cleansing of the feet and padding of the corns, the
patient was advised to wear thin acrylicblend socks to help wick away any additional moisture. He also was advised to avoid shoes that are made of synthetic materials, flip-flop-type sandals with open toes, and noncovered heels. Finally, our patient was instructed to obtain the therapeutic footwear his primary care physician had previously prescribed for him. He was instructed to wear this footwear at all times when walking. This patient will receive ongoing foot care every 3 months for corn care and as needed for any adverse events involving his feet or exacerbation of tinea pedis. REFERENCES 1. Birke J, Sims D. Plantar; sensory threshold in the ulcerative foot. Lepr Rev 1986;57:261-7. 2. Lower Extremity Amputation Prevention Program. Foot screening. Carville (LA): US Public Health Service, DHHS; 1994. 3. Collier J, Brodbeck C. Assessing the diabetic foot: plantar callus and pressure sensation. The Diabetic Educator 1993; 19: 503-8. 4. Mueller M. Identifying patients with diabetes mellitus who are at risk for lower extremity complications: use of the Semmes-Weinstein monofilaments. Physical Ther 1996;76:68-71. 5. Levin ME. Pathogenesis and management of diabetic foot lesions. In: Levin ME, et al, editors. The diabetic foot. 5th ed. St. Louis: Mosby; 1993.p.17-60. 6. McNeely M, Levin ME, O'Neal LW, Bowker JH, et al. The independent contributions of diabetic neuropathy and vasculopathy in foot ulceration. Diabetes Care 1995; 18:216-9. 7. Caputo G, et al. Assessment and management of foot disease in patients with diabetes. N Engl J Med 1994;331:854-60. 8. Aminoff M, et al. Clinical neurology. 3rd ed. Stanford (CT): Appleton and Lange; 1996. 9. Feldman E, ef al. A practical two-step quantitative clerical and electrophysiological assessment for the diagnosis and staging of diabetic neuropathy. Diabetes Care 1994;17:1281-6. 10. Saye DE. The foot: care of corns, calluses, ingrown nails and diabetic ulcers. Osfomy Wound Manage 1994;4:16-9,22-7. 11. Helfand AE. Nail and hyperkeratofic problems in the elderly foot. Am Fam Physician 1989;39:101-
10. 12. Leyden JL Tinea pedis pathophysiology and treatment. J Am Acad Derm 1994;31(suppl):S31-S33. 13. Leach D. Question and answer: dermatophytosis. J Am Acad Derm 1996;8:289-92. 14. Drake LA, Dinehart SM, Farmer ER, Goliz RW, Graham GF, et al. Guidelines of care for superficial mycotic infections of the skin: tinea corpods, tinea cruris, tinea facial, tinea manure, and tinea pedis. J Am Acad Derm 1996;34(Pt 1):282-6. 15. Belsey R, et al. Basic office microbiology. Oradell (N J): Medical Economics Comp, Inc;1990.p.87-93.
Q
ptions in Practice presents different m a n a g e m e n t approaches to the same clinical situation. You are invited to submit a brief case description, including the specialty nursing care provided, and several glossy, color photographs of the clinical situation. The case material will then be sent to another wound, ostomy, or c o n t i n e n c e care nurse, who will also address mana g e m e n t concerns. Alternative solutions to difficult wound, ostomy, or incontinence clinical situations will be pubiished.
TREATMENT OF A PATIENT WITH CORNS AND TINEA PEDIS A 66-year-old man was referred to our nurse-managed foot-and-wound-care clinic for routine foot care. His medical history was significant for a 30-year history of type II non-insulin-dependent diabetes mellitus controlled by oral agents and diet. In addition, he experienced multiple critical events over the past year, including an acute episode of pulmonary edema leading to myocardial infarction, coronary artery angioplasty, and right femoral popliteal bypass surgery, followed by a second myocardial infarction complicated by acute liver failure. His social history was remarkable for a 50-year habit of smoking one to two packs of cigarettes per day and occupational-related chronic venous stasis disease. Unfortunately, his job required that he stand for prolonged periods, typically varying from 10 to 12 hours per day. The patient's functional status was also limited. He was unable to reach his lower extremities and feet because of chronic shortness of breath. Consequently, foot and lower extremity care had to be performed by his wife or at our clinic.
Vascular Assessment Vascular assessment of the feet and lower extremities revealed significant abnormalities. The right dorsalis pedis and posterior tibial pulses were palpable but greatly diminished. The left dorsalis pedis and posterior tibial pulses were nonpalpable and barely audible on Doppler ultrasound.
The left foot was cold to touch and violaceous when placed in the dependent position. The limb was observed to blanche with elevation, demonstrating further evidence of arterial insufficiency. When compared with the left foot, the right foot was warmer and exhibited greater rubor.
Neurologic Assessment Sensory nerve testing of the feet was performed, including protective, vibratory, and proprioceptive assessments. A quantitative and reliable standard to use when testing for protective sensation is the 10-gram, (No. 5.07) Semmes-Weinstein calibrated n y l o n monofilament. 1 The ability to perceive the 10-gram monofilament indicates that the patient has protective pressure sensation in the foot. The following procedure is r e c o m m e n d e d when using the monofilament to evaluate sensation in a foot. The examiner should begin the evaluation by touching his or her hand with the monofilament, followed by touching the patient's hand, to provide reassurance that the filament is not sharp and that examination will not hurt. The examiner should limit distractions such as noise in the room and avoid touching other areas on the lower extremity. The patient is instructed to close the eyes, and the examiner begins the assessment by testing the fat pad on the plantar surface of the first, third, and fifth toes, followed by assessment of the area over the first, third, and fifth metatarsal heads. Care should be taken to avoid any callused areas. The clinical examination continues, moving to the midfoot and one area on the heel. 2-4 We prefer to use a pen-type 10-gram, No. 5.07 monofilament (North Coast SemmesWeinstein monofilament; North Coast Medical, Inc., San Jose, Calif.) In this case, sensory testing revealed a lack of protective sensation. This sensory deficit increased the risk for foot injury because the patient was unable to perceive light touch or light pressure applied to the plantar surface of the foot. Detection of this deficit was particularly important because prolonged exposure to pressure from a foreign body in the shoe, or an unrelieved and repetitive shearing or friction, could lead to injury, ulceration,
Karen Lukacs, RNCS, MSN, CWCN, is a Gerontological Clinical Nurse Specialist in the Department of Neurology of the Medical University of South Carolina, Charleston. Teresa Kelechi, RNCS, MSN, CWCN, is a Gerontological Clinical Nurse Specialist at the Center for the Study of Aging, Medical University of South Carolina, Charleston. Reprint requests: Karen Lukacs, RNCS, MSN, CWCN, Department of Neurology, MUSC, 171 Ashley Ave., Charleston, SC 29425.
J WOCN 1998;25:169-74. Copyright @ 1998by the Wound, Ostorny and Continence Nurses Society.
1071-5754/98/$5.00+ 0 21/9/89679
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Figure 1. Corn on second toe of right foot, hammer toes, and bunions.
first felt and when it stops. Assessment of the MTPJ is followed by testing of the lateral malleolus and medial malleolus. Vibration is a function of large (myelinated) nerve fibers. It is mildly diminished with normal aging, but significant defects are associated with peripheral polyneuropathy in a person with diabetes mellitus, central nervous system disorders, chronic alcohol abuse, or with exposure to toxins. 8 The patient should stop feeling the sensation at approximately the same time that the examiner no longer feels the vibration in the tuning fork. Findings should be documented as present, decreased, or absent. 8,9 In this case, the patient's vibratory sensation was assessed as absent. A third test for peripheral nerve function, position sense, or proprioception also was assessed. Position sense is tested by having the patient close the eyes while the examiner firmly grasps the great toe in the neutral (straight) position. The patient is asked to describe in which position the toe is during gentle manipulation into the following positions: (1) dorsiflexion, (2) plantar flexion, (3) return to neutral position. Findings are documented as present or absent. 8'9In this patient, position sense was preserved bilaterally.
Structural Assessment
Figure 2. Corn on fifth toe, hammer toes. infection, or amputation if not treated promptlyY Distal vibratory sensation was tested using a 128-Hz tuning fork. To administer this test, the patient is instructed to close the eyes. The clinician grasps the stem of the fork and taps the prongs against the hand, causing it to vibrate briskly. The examiner then places his or her index finger over the patient's metatarsophalangeal joint (MTPJ), located on the dorsum of the foot at the base of the first toe. The stem of the tuning fork is placed on the index finger. The patient is asked to report when the sensation or vibration is
Structurally, the feet were characterized by loss of the plantar fat pads (the dense subcutaneous tissue that absorbs shock and naturally decreases with age). The metatarsal heads were easily palpable and prominent. Bilateral bunions and hallux valgus deformities (deviation of the proximal great toe medially at the MTPJ causing the distal toe to deviate laterally) were present. The patient had rigid flexion contractures of the second, third, and fourth toes bilaterally (hammer toes), with small red area s on the proximal interphalangeal joint (PIPJ). A corn on the right, second PIPJ was noted (Figure 1). He also had a painful hard corn (heloma durum) on the lateral surface of the right fifth toe (Figure 2). Corns are hyperkeratoses and represent an accumulation of dehydrated epidermal cells that are often highly concentrated in the center of the lesion and gradually thinning at its periphery. 1°,11 This type of corn has a characteristic hard "built-up" center, with easily differentiated layers of epidermis. Corns most commonly occur as a result of abnormal
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p r e s s u r e , shearing, or frictional forces on s k i n of n o r m a l t h i c k n e s s . In c o n t r a s t , calluses are c a u s e d b y the s a m e conditions b u t arise on the p l a n t a r a n d l a t e r a l or m e d i a l surfaces of the f o o t - - s k i n that has a thicker e p i d e r m i s . This p a t i e n t ' s structural deformities were probably a t t r i b u t a b l e to the p r o l o n g e d s t a n d i n g r e q u i r e d b y his occupation, to his h i s t o r y of w e a r i n g n o n s u p p o r t i v e n a r r o w shoes, a n d to his diabetic p o t y n e u r o p a t h i e s .
Skin Assessment The skin b e l o w the knees e x h i b i t e d a dry, cracked, a n d flaky a p p e a r a n c e , w i t h h y p e r p i g m e n t a t i o n of the e p i d e r m i s at the ankle flare region. This p r o b a b l y repres e n t s a s e q u e l a of his c h r o n i c v e n o u s insufficiency. There w a s a dry, u n i f o r m scaling a p p e a r a n c e of the skin o v e r the f o r e f o o t a n d p l a n t a r surfaces. The skin b e t w e e n the first a n d s e c o n d toes bilate r a l l y h a d m a c e r a t i o n of the e p i d e r m i s a n d e x h i b i t e d a strong, foul odor. After debris from b e t w e e n the toes was cleaned, the skin retained its macerated and whitish a p p e a r a n c e , a l t h o u g h small p i n k a n d r e d fissures w e r e o b s e r v e d u n d e r this mace r a t e d skin. The p a t i e n t c o m p l a i n e d of occasional itchiness on the b o t t o m of the foot. H e s t a t e d that he h a d a l w a y s h a d " a t h l e t e ' s foot" a n d h a d b e e n t r e a t e d b y a d e r m a t o l o g i s t for f u n g a l infections in the past. Karen Lukacs, R N C S , M S N , C W C N : The i n i t i a l g o a l of s k i n care for this p a tient w a s to t r e a t his corns in an effort to r e d u c e the r i s k of u l c e r a t i o n or infect i o n of the u n d e r l y i n g a n d a d j a c e n t tissue. T r e a t m e n t of corns r e q u i r e s d e t e r m i n a t i o n of the causative factors. For this p a t i e n t , the corns w e r e p r i m a r i l y a consequence of the anatomical and functional c h a n g e of the f o r e f o o t a n d his i l l - f i t t i n g f o o t w e a r . His f o o t w e a r w a s t h o r o u g h l y i n s p e c t e d to d e t e r m i n e w h e t h e r his shoes or s o c k s w e r e c a u s i n g excessive p r e s s u r e on the a r e a s of c o r n d e v e l o p m e n t . Bec a u s e this p a t i e n t ' s corns w e r e on the t o p of the toe c o n t r a c t u r e ( h a m m e r toe) a n d on the lateral fifth toe, w e c o n c l u d e d t h a t the corns d e v e l o p e d as a r e s u l t of excessive p r e s s u r e a g a i n s t the sides a n d t o p of the shoe. W h e n i n s p e c t i n g footw e a r , w e r e c o m m e n d p a l p a t i n g the int e r i o r of the s h o e w i t h a g l o v e d h a n d to d e t e c t a n y r o u g h or U n e v e n a r e a s a n d to identify a n y foreign bodies. The h e i g h t of the toe b o x a n d the s h a p e of the shoe
it
Figure 3, A-B, Forefoot test. at the f o r e f o o t is also p a l p a t e d . The heel a n d sole of the shoe are t h e n i n s p e c t e d to d e t e r m i n e w h e t h e r there is a p a r t i c u l a r w e a r p a t t e r n i n d i c a t i n g an a l t e r e d gait such as that c a u s e d b y i n v e r s i o n or evers i o n of the foot. A f t e r a s s e s s m e n t of the p a t i e n t ' s footw e a r , a forefoot test is c o m p l e t e d . The p a t i e n t is a s k e d to s t a n d w i t h o u t footwear on a piece of 11x 14-inch white paper, a n d the o u t l i n e of the foot is t r a c e d w i t h a b l a c k m a r k e r (Figure 3,A). The shoe is then p l a c e d over the outline of the traced
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Figure 4. Tinea pedis, plantar surface with scaling. foot (Figure 3,B). A n y p o r t i o n of the tracing that falls o u t s i d e the s h o e ' s b o r d e r s provides an assessment of whether the foot m u s t be "squeezed" to fit the shoe. We use this test to identify excessive lateral pressure on the first a n d fifth toes a n d deform i t y of the toes as t h e y are forced into a n a r r o w shoe. In this case, the p a t i e n t ' s shoes were f o u n d to be n a r r o w and short, a n d t h e y were b e l i e v e d to contribute to his corns because they created excessive p r e s s u r e against the tops of the toes a n d the lateral aspect of the fifth toe.
Management of Corns The t r e a t m e n t of a corn is p r i m a r i l y d e t e r m i n e d b y its thickness, the a m o u n t of discomfort it p r o d u c e s , a n d the p a t i e n t or caregiver's abilities to follow a specific t r e a t m e n t regimen, l°,n Initially, the corn on this p a t i e n t ' s fifth toe r e q u i r e d s h a r p d e b r i d e m e n t (paring) of the h a r d outer layers a n d conservative care (buffing a n d p a d d i n g ) of the corn on the h a m m e r toe. The corn on the fifth toe was p a r e d using the following supplies: a basin, soap, water, towels, gloves, No. 3 scalpel h a n d l e , No. 17 r o u n d p o d i a t r y scalpel b l a d e or No. 88 chisel b l a d e a n d a p p r o p r i a t e h a n d l e , alcohol pads, gauze, and p o s t d e b r i d e m e n t p a d d i n g of choice. The affected area of the foot was washed with soap and
w a t e r a n d g e n t l y d r i e d . The p a t i e n t ' s foot w a s g r a s p e d in the n o n d o m i n a n t h a n d , a n d the toe w a s s e c u r e d w i t h the e x a m i n e r ' s fingers. The corn w a s d e b r i d ed using a "layer-to-layer" technique. Initially, small, thin l a y e r s w e r e p a r e d from the t o p u n t i l the b a s e of the corn w a s reached. We t o o k care n o t to exert excessive p r e s s u r e on the scalpel h a n d l e or the blade, and we avoided using a sawing m o t i o n d u r i n g p a r i n g . If a corn is p a r ticularly hard, it can be softened b y soaking in a b a s i n of w a r m w a t e r (98 ° F) for 3 to 5 m i n u t e s . A w a r m w e t w a s h c l o t h also can be p l a c e d over the corn for the s a m e a m o u n t of t i m e to p r o m o t e s o f t e n i n g . P a r i n g is c o n t i n u e d until it has a soft a n d s m o o t h a p p e a r a n c e a n d is level w i t h the s u r r o u n d i n g skin. P a r i n g is d i s c o n t i n u e d before this point if the corn becomes "pink" in color. After p a r i n g is c o m p l e t e d , the a r e a is w i p e d w i t h a m o i s t e n e d saline g a u z e p a d or alcohol p a d to r e m o v e a n y debris. We c o m p l e t e d sharp d e b r i d e m e n t of the outer layers of the corn on the fifth toe, a n d w e t a u g h t the p a t i e n t a n d his wife h o w to buff the corns on his h a m m e r toe. The buffing a n d p a d d i n g p r o c e d u r e require the following supplies: (1) a handheld acrylic nail file, (2) gloves, a n d (3) alcohol p a d s or g a u z e p a d s m o i s t e n e d w i t h saline. The p a t i e n t or family m e m b e r is t a u g h t to buff the corn b y first securing the toe with the nondominant hand, stretching a n d stabilizing the skin s u r r o u n d i n g the corn, a n d gently filing the corn in one d i r e c t i o n only. The p a t i e n t is t a u g h t to a v o i d using a s a w i n g motion; instead, he is i n s t r u c t e d to file u n t i l t h e a r e a has b e c o m e s m o o t h a n d e v e n w i t h the s u r r o u n d i n g skin. The p a t i e n t is a d v i s e d that the corn will become s o m e w h a t translucent a n d p i n k as the hyperkeratotic skin is buffed away. After this process, the skin is cleansed w i t h a m o i s t e n e d saline gauze p a d or alcohol p a d to ensure it is smooth. P a d d i n g t h e s e t y p e s of corns can be a c c o m p l i s h e d w i t h a v a r i e t y of p r o d u c t s , such as Dr. Scholl's L a m b s w o o l (Shering Plough, Memphis, Tenn.) or digit gel p a d s (Silipos, N i a g a r a Falls, N.Y.). The l a m b s w o o l is s e p a r a t e d into s t r a n d s that are a p p r o x i m a t e l y 5 to 8 inches long (forefoot sized) a n d ¼ to ½ inch wide. It is then w o v e n b e t w e e n a n d t h e n over the h a m m e r toes so that it covers the corn a n d d e c r e a s e s p r e s s u r e a n d friction f r o m the shoes. The d i g i t gel p a d s w i l l r e l i e v e
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pressure and friction over the digit. In addition, they are impregnated with silicone and mineral oil and designed to soften the underlying corn during wear. Both products should be used when footwear is worn. They do not need to be worn at night. Teresa Kelechi, MSN, RNCS, CWCN: Another goal for this patient was to alleviate the symptoms associated with the fungal infection of his feet (tinea pedis), and to improve the integrity of the skin by treating the inflammation, fissures, and peeling. Tinea pedis is the most common form of dermatophytosis, a fungal infection acquired from the soil, animals, and other humans. 12The most common transmission vector is other infected people, and those who frequent sports facilities, pools, and communal leisure facilities are also at risk. 13Contributing factors include warmth and high humidity, with constant occlusion of the skin surface, functional limitations that inhibit self-care, and chronic conditions that affect the immune system such as HIV or diabetes mellitus. D e r m a t o p h y t e s invade, infect, and persist in the stratum corneum and rarely penetrate below the surface of the epidermis or its appendages. The skin responds to this superficial infection by increased proliferation, which leads to scaling and epidermal thickening.~2 In this patient, scales were predominate on the plantar and medial surfaces of the foot (Figures 4 and 5). This presentation is called a moccasin-type infection, most likely caused by the dermatophyte Trichophy-
Figure 5. Tinea pedis with scales on right great toe.
ton rubrum. The patient exhibited symptoms of tinea pedis, including itching, scaling, and small breaks in the skin integrity. On close inspection, the skin between the first and second toes were remarkable for a bilateral whitish-appearing maceration with fissures. Interdigital toe-web infections usually start as a dermatophyte infection (Trichophyton rubrum and Trichophyton mentagrophytes), but various bacterial species and (rarely) Candida may complicate this infection. Scaling is the initial feature and, when the bacteria proliferate, maceration occurs (Figure 6). The terms dermatophytosis simplex and dermatophytosis complex have been proposed to address two forms of interdigital infection. Dermatophytosis simplex is characterized by scaling and fissures, whereas dermato-
Figure 6. Maceration of toe w e b space. phytosis complex causes maceration and exudate. 14 This patient had features of derrnatophytosis complex. The treatment of these infections tends to be empirically based, but greater diagnostic accuracy can be obtained when clinical diagnosis is verified by laboratory tests. A specimen can be obtained by scraping the active border or edge of a scale, lesion, or macerated area.
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The material is placed on a slide and a 10% to 15% potassium hydroxide (KOH) solution is added, along with a fungal stain. A positive KOH will show multiple septate hyphae under microscopic examination. 15 Trichophyton rubrum and Trichophyton mentagrophytes had been diagnosed previously in this patient by his dermatologist. His treatment was affected by several factors. His medical history revealed a recent episode of severe liver dysfunction; therefore, oral antifungal therapy was not an option because m a n y oral agents can be hepatotoxic. 14As an alternative, a topical antifungal agent (Lamisil Cream 1%) was selected. Unfortunately, the patient was not capable of reaching his own feet because of chronic shortness of breath. Therefore, his caregiver was instructed to wash his feet daily, paying particular attention to drying thoroughly between the toes. After the feet were dry, she was instructed to apply the cream twice each day to the plantar surfaces of his feet and toe web spaces until clinical signs and symptoms significantly improved, usually by day 7 of treatment. Topical therapy was recommended for a minimum of I week, but not to exceed 4 weeks. His condition began to improve on day 5 of therapy but, because of his long history of infection, he required approximately 25 days of treatment. Treatment of his dermatophytosis complex also required a broad-spectrum antibacterial agent. The dermatologist had instructed the patient to apply gentian violet, a tincture of dye. He did not like the resultant bluish purple skin staining because his preferred footwear was sandals (against our advice). Therefore, the tincture was discontinued, and his wife was taught to apply a triple antibiotic ointment twice daily. After treatment of the fungal infection, the patient and his wife were taught to care for the skin of the feet. They were instructed to bathe the feet with tepid water (94 ° F) and a standard commercial bar or liquid soap and to avoid soaking the feet. Soaking can be detrimental to the skin when it leads to overhydration, trapping of water between the toes, and maceration of the toe web spaces. Soaking also places additional physiological demands on a compromised vascular status if the temperature of the water is too high.5 After cleansing of the feet and padding of the corns, the
patient was advised to wear thin acrylicblend socks to help wick away any additional moisture. He also was advised to avoid shoes that are made of synthetic materials, flip-flop-type sandals with open toes, and noncovered heels. Finally, our patient was instructed to obtain the therapeutic footwear his primary care physician had previously prescribed for him. He was instructed to wear this footwear at all times when walking. This patient will receive ongoing foot care every 3 months for corn care and as needed for any adverse events involving his feet or exacerbation of tinea pedis. REFERENCES 1. Birke J, Sims D. Plantar; sensory threshold in the ulcerative foot. Lepr Rev 1986;57:261-7. 2. Lower Extremity Amputation Prevention Program. Foot screening. Carville (LA): US Public Health Service, DHHS; 1994. 3. Collier J, Brodbeck C. Assessing the diabetic foot: plantar callus and pressure sensation. The Diabetic Educator 1993; 19: 503-8. 4. Mueller M. Identifying patients with diabetes mellitus who are at risk for lower extremity complications: use of the Semmes-Weinstein monofilaments. Physical Ther 1996;76:68-71. 5. Levin ME. Pathogenesis and management of diabetic foot lesions. In: Levin ME, et al, editors. The diabetic foot. 5th ed. St. Louis: Mosby; 1993.p.17-60. 6. McNeely M, Levin ME, O'Neal LW, Bowker JH, et al. The independent contributions of diabetic neuropathy and vasculopathy in foot ulceration. Diabetes Care 1995; 18:216-9. 7. Caputo G, et al. Assessment and management of foot disease in patients with diabetes. N Engl J Med 1994;331:854-60. 8. Aminoff M, et al. Clinical neurology. 3rd ed. Stanford (CT): Appleton and Lange; 1996. 9. Feldman E, ef al. A practical two-step quantitative clerical and electrophysiological assessment for the diagnosis and staging of diabetic neuropathy. Diabetes Care 1994;17:1281-6. 10. Saye DE. The foot: care of corns, calluses, ingrown nails and diabetic ulcers. Osfomy Wound Manage 1994;4:16-9,22-7. 11. Helfand AE. Nail and hyperkeratofic problems in the elderly foot. Am Fam Physician 1989;39:101-
10. 12. Leyden JL Tinea pedis pathophysiology and treatment. J Am Acad Derm 1994;31(suppl):S31-S33. 13. Leach D. Question and answer: dermatophytosis. J Am Acad Derm 1996;8:289-92. 14. Drake LA, Dinehart SM, Farmer ER, Goliz RW, Graham GF, et al. Guidelines of care for superficial mycotic infections of the skin: tinea corpods, tinea cruris, tinea facial, tinea manure, and tinea pedis. J Am Acad Derm 1996;34(Pt 1):282-6. 15. Belsey R, et al. Basic office microbiology. Oradell (N J): Medical Economics Comp, Inc;1990.p.87-93.