- Email: [email protected]
Pustular tinea pedis
132 Brief reports
J AM ACAD DERMATOL JANUARY 2000
I
Pustular J. V Hirschmann,
tinea pedis
MD, and Gregory J. Raugi, MD, PhD Seattle, Washington
Pustules are uncommon in tinea pedis and may suggest a bacterial infection. We describe a patient with large pustules on his feet that contained hyphae on Gram’s stain of the pus and on a potassium hydroxide preparation of the pustule roof. Cultures were negative for bacteria, but grew Trichophyton rubrum. (J Am Acad Dermatol 2000;42:132-3.)
D
ermatophyte infection of the feet (tinea pedis) usually takes 1 of 4 forms.1 In the interdigital type, maceration, fissuring, erythema, and scaling occur in the toe webs, especially between the fourth and fifth digits. The hyperkeratotic variety consists of scaling and hyperkeratosis involving the plantar and lateral surfaces of the feet in a “moccasin” distribution. The third kind is an acute ulcerative process associated with maceration, denudation, and weeping, usually affecting the soles. The fourth comprises vesicles and blisters, usually near the instep and adjacent plantar surface. Sometimes pustules form in this type, but characteristically are small and affiliated with clear vesicles. Large pustules unassociated with vesicles must be rare in tinea pedis.
1. Close-up of dorsum of foot discloses irregularly shaped superficial pustules on dusky erythematous background.
Fig
CASE REPORT A 7%year-old man complained of pustules appearing on his left foot over the previous week. He had no pain, but had known atherosclerotic vascular disease causing arterial insufficiency of that leg; he had also received topical antifungal therapy for tinea pedis in the past. He did not have psoriasis and had not applied topical corticosteroids to the area. He was afebrile. He had yellow, thickened toenails with subungual hyperkeratosis and plantar scaling on both feet. The right foot was otherwise normal. The left foot, however, demonstrated dusky erythema on dependency that disappeared with elevation of the leg. On the dorsum and lateral surface of his foot were numerous large, discrete superficial pustules without accompanying vesicles or bullae (Fig 1).
From the Puget Sound Veterans Affairs Medical Center, and the Medical Service and Dermatology Section, University of Washington School of Medicine. Reprint requests: J.V. Hirschmann, MD, Medical Service (1 1 l), Puget Sound VA Medical Center, 1660 5 Columbian Way, Seattle, WA 98108. 16/54/101888
Gram’s stain of the pus revealed numerous neutrophils and a branching hypha (Fig 2), but no bacteria. A potassium hydroxide preparation of the roof of the pustule disclosed enormous numbers of hyphae. Bacterial cultures of the pus were sterile, rubrum grew on fungal although Trichophyton media. The pustules and plantar scaling cleared upon treatment with ultramicrosize griseofnlvin, 250 mg twice daily for 6 weeks. He received no other antimicrobial therapy
DISCUSSION The presence of dusky redness and pustules on the foot mimicked cellulitis complicated by superficial suppuration. The disappearance of the erythema on leg elevation, however, demonstrated that the discoloration represented dependent rubor caused by his arterial insufficiency rather than diffuse tissue inflammation, Several facts indicate that the pustules were from a mycotic rather than a bacterial infection. Hyphae were detectable on Gram’s stain of the pus and T rubrum grew from this material; bacteria were
J AM
ACAD
VOLUME
42,
Brief reports
DEKMATOL NUMBER
1, PART
133
1
With dermatophyte infections, neutrophils can appear in the epidermis or dermis as microabscesses in very inflamed lesions,3 especially those caused by zoophilic or geophilic species. The clinical correlate may be small pustules. Why large pustules formed in this patient’s infection with T rubrum, an anthropophilic organism that usually provokes little inflammation4 is unclear. Their presence illustrates, however, that dermatophyte infection belongs in the differential diagnosis of pustules on the feet.
Fig 2. Gram’s stain of pus from one lesion reveals branching hypha. Neutrophils were abundant in other portions of slide.
neither visible on stain nor isolated on culture. Abundant hyphae were also present on a potassium hydroxide preparation of the roof of the pustule. Finally, the pustules disappeared during treatment with griseofulvin, which is not effective against bacteria,a and the patient received no other antimicrobial therapy.
REFERENCES 1. Martin AG, Kobayashi GS.Superficial fungal infection:dermatophytosis, tinea nigra, piedra. In: Freedberg IM, Eisen AZ, Wolff K, et al,editors.Fitzpatrick’s Dermatology in general medicine.%h ed. New York: McGraw-Hill; 1999. p. 2337-57. 2. Gupta AK, Sauder DN, Shear NH. Antifungal agents: an overview. Part I. J Am Acad Dermatol 1994;30:677-98. 3. Hay RJ, Chandler FW. Superficial fungal infections. In: Connor DH, Chandler FW, Schwartz DA, Manz HJ, Lack EE, editors. Pathology of infectious diseases. Stamford (CT): Appleton & Lange; 1997. p. 1097-l 03. 4. Hay RJ, Moore M. Mycology. In: Champion RH, Burton JL, Burns DA,Breathnach SM,editors.Rook,Wilkinson,EblingTextbookof dermatology. 6th ed. Oxford: Blackwell Science; 1998. p. 1277376.
J AM ACAD DERMATOL JANUARY 2000
I
Pustular J. V Hirschmann,
tinea pedis
MD, and Gregory J. Raugi, MD, PhD Seattle, Washington
Pustules are uncommon in tinea pedis and may suggest a bacterial infection. We describe a patient with large pustules on his feet that contained hyphae on Gram’s stain of the pus and on a potassium hydroxide preparation of the pustule roof. Cultures were negative for bacteria, but grew Trichophyton rubrum. (J Am Acad Dermatol 2000;42:132-3.)
D
ermatophyte infection of the feet (tinea pedis) usually takes 1 of 4 forms.1 In the interdigital type, maceration, fissuring, erythema, and scaling occur in the toe webs, especially between the fourth and fifth digits. The hyperkeratotic variety consists of scaling and hyperkeratosis involving the plantar and lateral surfaces of the feet in a “moccasin” distribution. The third kind is an acute ulcerative process associated with maceration, denudation, and weeping, usually affecting the soles. The fourth comprises vesicles and blisters, usually near the instep and adjacent plantar surface. Sometimes pustules form in this type, but characteristically are small and affiliated with clear vesicles. Large pustules unassociated with vesicles must be rare in tinea pedis.
1. Close-up of dorsum of foot discloses irregularly shaped superficial pustules on dusky erythematous background.
Fig
CASE REPORT A 7%year-old man complained of pustules appearing on his left foot over the previous week. He had no pain, but had known atherosclerotic vascular disease causing arterial insufficiency of that leg; he had also received topical antifungal therapy for tinea pedis in the past. He did not have psoriasis and had not applied topical corticosteroids to the area. He was afebrile. He had yellow, thickened toenails with subungual hyperkeratosis and plantar scaling on both feet. The right foot was otherwise normal. The left foot, however, demonstrated dusky erythema on dependency that disappeared with elevation of the leg. On the dorsum and lateral surface of his foot were numerous large, discrete superficial pustules without accompanying vesicles or bullae (Fig 1).
From the Puget Sound Veterans Affairs Medical Center, and the Medical Service and Dermatology Section, University of Washington School of Medicine. Reprint requests: J.V. Hirschmann, MD, Medical Service (1 1 l), Puget Sound VA Medical Center, 1660 5 Columbian Way, Seattle, WA 98108. 16/54/101888
Gram’s stain of the pus revealed numerous neutrophils and a branching hypha (Fig 2), but no bacteria. A potassium hydroxide preparation of the roof of the pustule disclosed enormous numbers of hyphae. Bacterial cultures of the pus were sterile, rubrum grew on fungal although Trichophyton media. The pustules and plantar scaling cleared upon treatment with ultramicrosize griseofnlvin, 250 mg twice daily for 6 weeks. He received no other antimicrobial therapy
DISCUSSION The presence of dusky redness and pustules on the foot mimicked cellulitis complicated by superficial suppuration. The disappearance of the erythema on leg elevation, however, demonstrated that the discoloration represented dependent rubor caused by his arterial insufficiency rather than diffuse tissue inflammation, Several facts indicate that the pustules were from a mycotic rather than a bacterial infection. Hyphae were detectable on Gram’s stain of the pus and T rubrum grew from this material; bacteria were
J AM
ACAD
VOLUME
42,
Brief reports
DEKMATOL NUMBER
1, PART
133
1
With dermatophyte infections, neutrophils can appear in the epidermis or dermis as microabscesses in very inflamed lesions,3 especially those caused by zoophilic or geophilic species. The clinical correlate may be small pustules. Why large pustules formed in this patient’s infection with T rubrum, an anthropophilic organism that usually provokes little inflammation4 is unclear. Their presence illustrates, however, that dermatophyte infection belongs in the differential diagnosis of pustules on the feet.
Fig 2. Gram’s stain of pus from one lesion reveals branching hypha. Neutrophils were abundant in other portions of slide.
neither visible on stain nor isolated on culture. Abundant hyphae were also present on a potassium hydroxide preparation of the roof of the pustule. Finally, the pustules disappeared during treatment with griseofulvin, which is not effective against bacteria,a and the patient received no other antimicrobial therapy.
REFERENCES 1. Martin AG, Kobayashi GS.Superficial fungal infection:dermatophytosis, tinea nigra, piedra. In: Freedberg IM, Eisen AZ, Wolff K, et al,editors.Fitzpatrick’s Dermatology in general medicine.%h ed. New York: McGraw-Hill; 1999. p. 2337-57. 2. Gupta AK, Sauder DN, Shear NH. Antifungal agents: an overview. Part I. J Am Acad Dermatol 1994;30:677-98. 3. Hay RJ, Chandler FW. Superficial fungal infections. In: Connor DH, Chandler FW, Schwartz DA, Manz HJ, Lack EE, editors. Pathology of infectious diseases. Stamford (CT): Appleton & Lange; 1997. p. 1097-l 03. 4. Hay RJ, Moore M. Mycology. In: Champion RH, Burton JL, Burns DA,Breathnach SM,editors.Rook,Wilkinson,EblingTextbookof dermatology. 6th ed. Oxford: Blackwell Science; 1998. p. 1277376.