Dusky patches in chronic leg lymphedema – An uncommon presentation of Stewart‐Treves syndrome

Abstract

the lesion of the proximal medial right thigh. Suspecting dermatophytid, we decided to perform further investigation through RCM. In the RCM, evaluation of the groin and foot revealed several bright linear structures (mycelium), as well as some inflammatory cells were found scattered in the stratum corneum (Fig. 1c). Regarding the thigh lesion, no fungal structures were seen, but mild perivascular inflammatory infiltrate and spongiosis (dark areas in the epidermis, with broadband intercellular spaces) were appreciated (Fig. 2b), confirming the diagnosis of dermatophytid. Later, fungal culture revealed the presence of Trichophyton mentagrophytes. Therapy with oral itraconazole 100 mg every 12 h was started. After 4 weeks of treatment, all lesions vanished.A dermatophytid is an id reaction caused by an immunologic response to the fungal antigens that derive from the fungal pathogen, away from the primary skin lesion. Normally, it appears 1 or 2 weeks after the primary infection and can cause significant pruritus. 2 Upon direct microscopic evaluation and fungal culture, the lesions are pathogen-negative. The id tends to resolve after the primary lesion has been treated, as was the case of our patient. 2 The RCM offers a prompt, easy, and noninvasive technique for the diagnosis of dermatophytic infections and id reactions, reducing the number of skin scrapings or biopsies. Moreover, RCM offers the possibility to repeat the exam on different body sites and at different times to evaluate therapeutic response.More comparative studies including histopathologic and RCM evaluation should be made to confirm the utility and sensitivity of RCM for fungal infections.