Lichen planus (LP) is a benign inflammatory disease characterized by pruritic violaceous papules involving the skin, genitalia, or oral mucosa. Recent studies have implicated hepatitis C virus (HCV) in the pathogenesis of LP. In this meta-analysis of 70 studies, Shengyuan et al demonstrate a statistically significant association of LP with HCV infection. These data support screening patients with LP for HCV and suggest that HCV and LP may be considered aggravating factors for each other.
Combination therapy of acne vulgaris is often more effective than monotherapy, but understanding the limitations and risks of such therapy is essential to maximize safety and efficacy. A recent study revealed that 7% of patients using topical dapsone gel, 5%, in combination with benzoyl peroxide developed temporary skin discoloration. Dubina and Fleischer further investigate the interactions between topical dapsone gel, sulfacetamide sodium lotion, benzoyl peroxide, clindamycin phosphate, and retinoids. Their data reveal that benzoyl peroxide products produce an orange-brown discoloration when mixed with either sulfacetamide or dapsone. Even dapsone alone imparted a slight color. These data may be used by dermatologists to develop combination treatment plans that avoid combining these ingredients in a manner that would lead to discoloration.
Leishmania tropica is a protozoan species that typically causes cutaneous leishmaniasis (CL) after an incubation period of weeks to months. Clinical manifestations of CL include verrucous papules, plaques, and disfiguring ulcerations on the lower legs and arms. In this case report, Weiss et al describe a 17-year-old girl who had lived in the United States for 4 years. After 6 months of weight loss, abdominal pain, splenomegaly, and fatigue, histopathologic examination of pretibial ulceration specimens confirmed L tropica infection. Laboratory examination suggested an unusual viscerotropic variant. This exceptional case suggests that leishmaniasis be considered a diagnostic possibility even in individuals who have left endemic areas months or years prior to symptom onset.
Exposure to UV radiation (UVR) from indoor tanning lamps has been linked with both melanoma and squamous cell carcinoma. In the United States, indoor tanning is especially popular among adolescent girls, which may explain the recently reported rise in melanoma incidence among US young adult women. In this cross-sectional study of indoor tanning facilities regarding youth access, Pichon et al found that 87% of all facilities required parental consent. In states with youth access laws, facilities were more likely to require written parental consent. Compliance with US Food and Drug Administration–recommended sessions-per-first-week frequency was less than 11%. The authors suggest that indoor tanning bans may reduce youth access in a more direct way and more forcefully educate parents about the dangers of indoor tanning than the current recommendations and parental consent requirements do.
Some epidemiologic studies suggest that smoking may be one of several environmental risk factors for lupus erythematosus (LE) in genetically predisposed individuals. Alcohol consumption, on the other hand, seems to be associated with a decreased risk of LE. In this multicentric prospective study, Boeckler et al found strong evidence of a cumulative and dose effect for smoking and cutaneous involvement in LE. The mechanisms of this association remain unclear: toxic chemicals in tobacco smoke, phototoxic effects of cigarette smoke, immunomodulatory effects of cigarette smoking, and inactivation of antimalarial agents are potential explanations. The authors also suggest that cigarette smoking may not be a risk factor per se, but predisposition to LE and smoking dependency could have a common genetic background.
This Month in Archives of Dermatology. Arch Dermatol. 2009;145(9):978. doi:10.1001/archdermatol.2009.217