Dapsone induced acute photosensitivity dermatitis; a case report and review of literature.

Dapsone is one of the main constituents of anti-leprosy treatment and has been in use for various dermatological and non-dermatological indications since the 1940s. Dapsone-induced photosensitivity is a rare complication. Only 11 cases seem to have been reported in the literature. We report a case of dapsone-induced photosensitivity in an Indian patient with leprosy, and briefly review the literature. Dapsone (diaminodiphenyl sulphone or DDS) is the most commonly used anti-leprosy drug since the 1940s. Apart from leprosy, it is used for various other infectious and non- infectious dermatoses as well as for prevention of Pneumocystis carinii pneumonia in HIV infected patients. It is one of the main constituents of multidrug therapy (MDT) in leprosy by virtue of its anti-mycobacterial properties. It acts by interference with folate metabolism. Because of its inhibitory effect in neutrophil chemotaxis and neutrophilic oxygen burst, it acts as a potent anti-inflammatory agent. Documented cutaneous adverse effects of dapsone include generalised maculopapular rash, exfoliative dermatitis, toxic epidermal necrolysis, erythema multiforme, erythema nodosum, pustular and acneiform skin eruptions. Photosensitivity dermatitis is a very rare side-effect of dapsone and to the best of our knowledge, only 11 cases have been reported in the literature to date.