Many cases of superinfected hidradenitis suppurativa (HS) involve multiple species of bacteria, but gas-producing infections are rare and can complicate the clinical picture. Additionally, recognizing squamous cell carcinoma (SCC) as a complication of longstanding HS is imperative. Herein, we present a unique case of a severe emphysematous HS that was initially mistaken for Fournier gangrene and eventually diagnosed as superinfected SCC.

Thiotepa is a common alkylating agent known to precipitate cutaneous reactions consistent with toxic erythema of chemotherapy, including erythema and hyperpigmentation. Herein, we describe an atypical case of malignant intertrigo involving preferential erythema and desquamation not only of skin folds but also of occluded areas after thiotepa-based conditioning. The diagnosis was complicated by concurrent stomatitis and oral petechiae in the setting of autologous stem cell transplant 11 days prior for diffuse large B-cell lymphoma. Histopathological examination from two cutaneous sites demonstrated epidermal dysmaturation and eccrine gland necrosis consistent with thiotepa-induced desquamation and not Stevens-Johnson syndrome or graft-versus-host-disease. Malignant intertrigo can present with extensive cutaneous involvement, as evidenced by our patient who had 25% body surface area affected. Mucosal involvement is common with most chemotherapeutic regimens and its presence should not deter the astute clinician from consideration of a diagnosis of toxic erythema of chemotherapy. No further interventions were needed and the patient healed spontaneously.

The original article was published on February 15, 2020 and corrected on March 15, 2020.The revised version of the article corrects the contact information of the Corresponding Author. The changes appear in the revised online PDF copy of this article.