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Adhesion of Staphylococcus aureus to horny layer: Role of fibrinogen
Journal of the American Academy of Dermatology Volume 36, Number 5, Part 1
Pearls of wisdom
775
Abstracts from the literature Dissecting cellulitis of the scalp: response to isotretinoin
cumstances, but many cases are the result of venom toxicity rather than allergy.
Scerri L, Williams HC, Allen BR. B r J Dermatol 1996;134:1105-8.
Elizabeth A. A b e l M D
Dissecting cellulifis of the scalp is a difficult condition to treat. The use of isotretinoin has been previously reported, but with rapid relapse after a 3- to 4-month course of treatment. The aautho~ report a complete response to isotretinoin at a dose of 0.75 to 1.0 mg/kg, which was maintained for 9 to 11 months. No relapse of dissecting cellulitis of the scalp was found in the two patients followed up for 2% years. COMMENT:Aggressive surgery has cleared the lesions of dissecting cellulitis of the scalp in some patients, but this prolonged treatment with isotretinoin produced a durable response without surgical risk. Early treatment with this regimen might prevent hair loss and scarring, Mary E. Maloney, M D
What physicians should k n o w about Africanized honeybees Sherman RA. West J M e d 1995;163:541-6. Sting emergencies can result from the Africanized or "killer" honeybee, which is established in Texas and since 1990 has spread to California, Arizona, and other areas in the southern United States. The Africanized bees, which are actually a hybrid, swarm more readily and frequently and sling more collectively than the European honeybee. It is the cumulative dose from multiple stings that accounts for the morbidity and mortality caused by these "killer bees," even in nonallergic persons. Avoidance of hives is key. Because the bees are known for aggressive defense of their colony, persons at risk should avoid wearing brightly colored clothing or fragrances and making sudden movements. Volatile chemicals that are released in the sting attack from the bees' glands result in the recruitment of additional bees toward the victim. Symptoms range from local pain, itching, and urticarial edema to severe systemic reactions with respiratory distress, gastrointestinal toxicity, and hypotension. Reactions, including renal failure, may be delayed for 8 to 24 hours. Preventive measures include public education, readily accessible first aid, and surveillance and removal of hives. Immunoprophylaxis may be useful in some cir-
Adhesion of Staphylococcus aureus to horny layer: role of fibrinogen Kanzaki H, Morishita Y, Akiyama H, et al. J Dermatol Sci 1996;12:132-9. Staphylococcus aureus heavily colonizes the skin of patients with atopic dermatitis and other eczemas. The authors of this study attempted to determine the reason by inoculating various strains of S. aureus onto the backs of mice after abrading the skin. Biopsy specimens of skin were processed for examination by electron microscopy with the use of goat and rabbit polyclonal antibodies against mouse fibrinogen. Cowan I strain S. aureus (which has high affmity for fibfinogen and fibronecfin) became coated with fibrinogen, which bridged the gap between the bacterial surfaces and horny cells. Fibfinogen did not bridge the gap between C7 and Woods 46 strains (with no protein A on their surfaces) and horny cells. Fibrinogen is apparently involved in binding S. aureus to the skin surface.
COMMENT: S. aureus can also bind to horny cells via a glycoprotein (glycocalix.9) on its surface. Plasma augments this binding. Because water can wash off bacteria and fibrinogen and because I believe heavy colonization of skin with S. aureus aggravates atopic dermatitis, I usually recommend baths and showers to patients with atopic dermatitis (followed by applications of emollients). Mark V. DahL M D
Cryptococcosis in the era of AIDS 100 years after the discovery of Cryptococcus neoformans Mitchell TG, Perfect JR. Clin Microbiol Rev 1995; 8:515-48. The authors have given us an exhaustive and authoritative review (33 pages; 529 references) of cryptococcosis and its etiologic agent, Cryptococcus neoformans, an encapsulated yeast first isolated from peach juice. The
Pearls of wisdom
775
Abstracts from the literature Dissecting cellulitis of the scalp: response to isotretinoin
cumstances, but many cases are the result of venom toxicity rather than allergy.
Scerri L, Williams HC, Allen BR. B r J Dermatol 1996;134:1105-8.
Elizabeth A. A b e l M D
Dissecting cellulifis of the scalp is a difficult condition to treat. The use of isotretinoin has been previously reported, but with rapid relapse after a 3- to 4-month course of treatment. The aautho~ report a complete response to isotretinoin at a dose of 0.75 to 1.0 mg/kg, which was maintained for 9 to 11 months. No relapse of dissecting cellulitis of the scalp was found in the two patients followed up for 2% years. COMMENT:Aggressive surgery has cleared the lesions of dissecting cellulitis of the scalp in some patients, but this prolonged treatment with isotretinoin produced a durable response without surgical risk. Early treatment with this regimen might prevent hair loss and scarring, Mary E. Maloney, M D
What physicians should k n o w about Africanized honeybees Sherman RA. West J M e d 1995;163:541-6. Sting emergencies can result from the Africanized or "killer" honeybee, which is established in Texas and since 1990 has spread to California, Arizona, and other areas in the southern United States. The Africanized bees, which are actually a hybrid, swarm more readily and frequently and sling more collectively than the European honeybee. It is the cumulative dose from multiple stings that accounts for the morbidity and mortality caused by these "killer bees," even in nonallergic persons. Avoidance of hives is key. Because the bees are known for aggressive defense of their colony, persons at risk should avoid wearing brightly colored clothing or fragrances and making sudden movements. Volatile chemicals that are released in the sting attack from the bees' glands result in the recruitment of additional bees toward the victim. Symptoms range from local pain, itching, and urticarial edema to severe systemic reactions with respiratory distress, gastrointestinal toxicity, and hypotension. Reactions, including renal failure, may be delayed for 8 to 24 hours. Preventive measures include public education, readily accessible first aid, and surveillance and removal of hives. Immunoprophylaxis may be useful in some cir-
Adhesion of Staphylococcus aureus to horny layer: role of fibrinogen Kanzaki H, Morishita Y, Akiyama H, et al. J Dermatol Sci 1996;12:132-9. Staphylococcus aureus heavily colonizes the skin of patients with atopic dermatitis and other eczemas. The authors of this study attempted to determine the reason by inoculating various strains of S. aureus onto the backs of mice after abrading the skin. Biopsy specimens of skin were processed for examination by electron microscopy with the use of goat and rabbit polyclonal antibodies against mouse fibrinogen. Cowan I strain S. aureus (which has high affmity for fibfinogen and fibronecfin) became coated with fibrinogen, which bridged the gap between the bacterial surfaces and horny cells. Fibfinogen did not bridge the gap between C7 and Woods 46 strains (with no protein A on their surfaces) and horny cells. Fibrinogen is apparently involved in binding S. aureus to the skin surface.
COMMENT: S. aureus can also bind to horny cells via a glycoprotein (glycocalix.9) on its surface. Plasma augments this binding. Because water can wash off bacteria and fibrinogen and because I believe heavy colonization of skin with S. aureus aggravates atopic dermatitis, I usually recommend baths and showers to patients with atopic dermatitis (followed by applications of emollients). Mark V. DahL M D
Cryptococcosis in the era of AIDS 100 years after the discovery of Cryptococcus neoformans Mitchell TG, Perfect JR. Clin Microbiol Rev 1995; 8:515-48. The authors have given us an exhaustive and authoritative review (33 pages; 529 references) of cryptococcosis and its etiologic agent, Cryptococcus neoformans, an encapsulated yeast first isolated from peach juice. The