SAEM Clinical Images Series: Man with a Recurrent Rash

Skin findings typically arise within two days of exposure and then more rapidly with subsequent exposures [2]. Characteristically, recurrent lesions appear at the same sites as prior lesions (hence “fixed”) but may arise in additional locations. The rash is classically divided into two phases: an acute phase of pruritic violaceous patches and plaques with central duskiness, followed by a residual phase of hyperpigmentation that can last several months. The sulfonamide moiety of TMP-SMX is a common cause of FDE [3]. Management of FDE anchors on identification and discontinuation of the causative agent. The majority of cases involve five or fewer lesions, however generalized or bullous cases (> 10% total body surface area, or involvement of 3 or more anatomic sites) [1], may require aggressive wound care and carry a mortality rate up to 22% [4]. Topical or systemic steroids are common adjuncts and there is limited evidence suggesting the utility of systemic cyclosporine for severe cases [1]. Patients need to be carefully advised on the risks of specific medication use and can expect a gradual resolution of lesions over the coming months.