Androgen physiology and the cutaneous pilosebaceous unit.

Hormones play an important role in cutaneous physiology. The androgen hormones are of particular relevance in modulating hair growth and sebum production in the pilosebaceous unit, which is comprised of the hair follicle and sebaceous gland. Testosterone arising from the circulation is converted peripherally to its more potent, reduced form, dihydrotestosterone, by the enzyme 5 alpha-reductase.

Angiocentric primary cutaneous T-cell-rich B-cell lymphoma: a case report and review of the literature.

Background: T-cell-rich B-cell lymphoma (TCRBCL) is an uncommon B-cell lymphoma, which is characterized histologically by a small number of neoplastic B cells surrounded by large numbers of nonneoplastic T cells. Diagnosis is frequently difficult because the neoplastic 'B-cell population may be quite sparse, and immunohistochemical and molecular analysis to identify the B-cell origin and clonality of the cells is necessary.

Methods: In this report we present an additional case of primary cutaneous TCRBCL with immunohistochemical and gene rearrangement studies and review the literature of this unusual entity.

Minocycline-induced hyperpigmentation in patients with pemphigus and pemphigoid.

Background: Immunosuppressive medications typically used to treat the immunobullous disorders pemphigus vulgaris, pemphigus foliaceous, and bullous pemphigoid can have serious adverse effects. The tetracycline family of antibiotic drugs has been shown to be effective in the treatment of these conditions with a more favorable side effect profile. Minocycline hydrochloride use has been associated with various forms of hyperpigmentation, and its incidence is well reported in acne vulgaris and rheumatoid arthritis.

Treatment of cutaneous sarcoidosis using phonophoresis.

Sarcoidosis is a multiple-system disorder of unknown origin characterized histologically by epithelioid granulomas with little or no necrosis. We describe a 32-year-old female patient with a history of systemic sarcoidosis and common variable immunodeficiency with recurrent, multiple, soft, erythematous and violaceous nodules on the back of her left hand. Her lesions responded to phonophoresis after unsuccessful treatment with topical and intralesional corticosteroids.