Update on the use of dapsone in dermatology.

Dapsone (4,4'-diaminodiphenylsulfone) is the only remaining sulfone used in anthropoid therapeutics and is commercially available as an oral formulation, an inhaled preparation, and a 5% or 7.5% cream. Dapsone has antimicrobial effects stemming from its sulfonamide-like ability to inhibit the synthesis of dihydrofolic acid. It also has anti-inflammatory properties such as inhibiting the production of reactive oxygen species, reducing the effect of eosinophil peroxidase on mast cells and down-regulating neutrophil-mediated inflammatory responses. This allows for its use in the treatment of a wide variety of inflammatory and infectious skin conditions. Currently in dermatology, the US Food and Drug Administration (FDA)-approved indications for dapsone are leprosy, dermatitis herpetiformis, and acne vulgaris. However, it proved itself as an adjunctive therapeutic agent to many other skin disorders. In this review, we discuss existing evidence on the mechanisms of action of dapsone, its FDA-approved indications, off-label uses, and side effects.

Cutaneous sarcoidosis: clinicopathologic study of 76 patients from Lebanon.

BACKGROUND: Sarcoidosis is a multi-system granulomatous disease of unknown etiology. The skin is involved in 25% of cases. Studies on cutaneous sarcoidosis from our region are lacking. OBJECTIVES: This study was conducted to describe clinical and histopathologic findings in all patients diagnosed with cutaneous sarcoidosis at the American University of Beirut Medical Center between 1992 and 2010 and to compare findings with those published in the literature. METHODS: Clinical charts of patients with cutaneous sarcoidosis were retrospectively reviewed. Extracutaneous lesions were classified by organ involvement. Treatment was documented. Pathology specimens were reviewed. RESULTS: Cutaneous sarcoidosis was diagnosed in 76 Lebanese patients, 79% of whom were women. Mean age at diagnosis was 48 years. A total of 29% of patients had systemic disease that was commonly associated with lupus pernio lesions and subcutaneous sarcoidosis. The most common cutaneous lesions were sarcoidal plaques. The histopathologic features in our series did not differ from those described in the literature, except for the documented presence of a grenz zone. Interestingly, 23% of biopsy specimens contained perineural granulomas, raising the possibility of tuberculoid or borderline tuberculoid leprosy. Foreign bodies were detected in 10% of cases (all had systemic involvement), supporting the opinion that sarcoidosis and granulomatous foreign body reaction are not mutually exclusive. CONCLUSIONS: The clinical and histopathologic features of cutaneous sarcoidosis patients in the present series are generally comparable with those published in the literature, with minor differences. Clinically, the most commonly seen lesion was plaque. Microscopically, cutaneous sarcoidosis may exhibit a grenz zone and may show perineural inflammation and foreign bodies.