Hidradenitis Suppurativa Secondary to Treatment With a Gamma Secretase Inhibitor

This document reports a case of a 38-year-old man who developed Hidradenitis suppurativa (HS)-like inflammatory lesions as a side effect of treatment with a gamma secretase inhibitor (GSC inhibitor), which he was taking as part of a phase II clinical trial for a desmoid tumor. The patient, who had no personal or family history of HS and was a smoker, experienced a clear onset of skin lesions following the initiation of the GSC inhibitor therapy. Despite various treatments, including antibiotics, steroids, and vitamin supplementation, the lesions did not improve, leading to the initiation of treatment with the IL-17 inhibitor secukinumab. The case underscores the importance of recognizing and managing skin toxicity associated with GSC inhibitors, which are emerging treatments for desmoid tumors but have been associated with skin-related side effects in clinical trials. The authors suggest that factors such as smoking and folate deficiency may have exacerbated the patient's inflammatory symptoms and propose that oral retinoids could be considered for maintenance therapy once inflammation is controlled. This case contributes to the understanding of drug-induced HS and the role of GSC in HS pathogenesis.