Faculty Bibliography

We report the case of a 63-year-old obese man with a rapid-onset of widespread acanthosis nigricans (AN) in the setting of having recently initiated treatment with niacin for dyslipidemia. Although obesity and insulin-resistance are risk factors for AN, AN associated with endocrine dysfunction tends to have a more gradual onset and limited involvement. Owing to our patient's age, the rapid onset, and extensive distribution of his eruption, we initially were concerned about paraneoplastic AN. However, an evaluation for a malignant condition was negative. The timing of the onset of our patient's eruption within several months of starting niacin therapy is consistent with niacin-induced AN. Niacin is known to cause rapidly progressive, widespread AN that is reversible upon discontinuation of the medication. We discuss the pathogenesis of AN, which is thought to be the final common manifestation of stimulation of different subtypes of tyrosine kinase receptors by various epidermal growth factors.

A 49-year-old man with advanced HIV/AIDS on anti-retroviral therapy (HAART) and trimethoprim-sulfamethoxazole (TMP-SMX) presented with a several-month history of pruritic, erythematous, lichenified papules that coalesced into hyperkeratotic plaques on the trunk and extremities in a sun-exposed distribution. He shortly thereafter developed a progressive depigmentation over more than 80 percent of his body surface area. A biopsy specimen of an erythematous plaque on the trunk showed a superficial and mid-dermal infiltrate of lymphocytes with eosinophils, most consistent with either chronic lichenoid drug eruption or atypical lymphoproliferative disorder (ACLD) of HIV. The patient's lichenoid skin disease has persisted despite discontinuation of TMP-SMX, although it has improved partially with administration of topical glucocorticoids and acitretin. His depigmentation has continued to progress. We discuss the overlapping diagnostic entities which may be comprised by this patient's clinical disease, and highlight a unique presentation of the complex interaction between HIV infection and the skin.

A 50-year-old man with hepatitis C virus infection and liver cirrhosis, who was awaiting transplantation, was admitted to the Transplant Surgery Service for treatment of a pleural effusion and an elevated ammonia level. Skin examination showed violaceous, firm nodules on the right thigh, which had been present for eight months. A fungal culture showed Trichophyton rubrum. The patient was started on itraconazole with improvement in the eruption.

Psoriasis is a chronic T-cell-mediated inflammatory disease of the skin and joints that affects 1-3% of the world population. Conventional treatments for moderate to severe psoriasis are associated with broadband immunosuppression and/or organ toxicities that can be problematic when used long term. Advances in the understanding of psoriasis pathogenesis have led to targeted therapy in the form of biologics. These agents have gained popularity as safe, effective, and convenient alternatives for the treatment of chronic, moderate to severe plaque psoriasis. This review will focus on the five main biologics used in the treatment of moderate to severe plaque psoriasis: efalizumab, alefacept, etanercept, infliximab and adalimumab. Mechanisms of action, guidelines for usage, efficacy data, and safety concerns will be discussed for each biologic. In addition, the new Th17 biologics and their role in psoriasis pathogenesis will also be examined.