Case Report of Primary Cutaneous Cryptococcosis Associated With Secukinumab Use (Il-17a Inhibitor)

Primary cutaneous cryptococcosis (PCC) is a rare clinical entity characterized by direct skin infection by Cryptococcus spp., usually after local trauma, without evidence of systemic dissemination or prior pulmonary involvement. Typically, cutaneous manifestations of cryptococcosis result from hematogenous dissemination in immunosuppressed individuals, especially those with HIV/AIDS, transplant recipients, or patients using immunosuppressive drugs. PCC, however, is rarely reported in the literature, particularly in patients undergoing immunobiological therapy. This case involves a 33-year-old man with psoriasis and primary sclerosing cholangitis with liver cirrhosis, receiving monthly secukinumab (a monoclonal antibody IL-17A inhibitor), who developed a cutaneous ulcer on the left forearm after trauma from a wooden pallet. The condition evolved without systemic symptoms or abnormalities in routine laboratory tests. Biopsy and culture of the lesion revealed Cryptococcus gattii. No evidence of systemic or pulmonary fungal infection was found. Treatment consisted of amphotericin B deoxycholate and fluconazole for 14 days, followed by maintenance fluconazole, with clinical improvement and lesion healing. However, two months after discharge, the patient developed severe infection and septic shock due to Staphylococcus aureus bacteremia, resulting in death. The association between PCC and secukinumab use is noteworthy, as there are no previous reports of primary cutaneous cryptococcosis in patients receiving IL-17 inhibition. Secukinumab, approved for psoriasis and spondyloarthropathies, has mucocutaneous candidiasis and other superficial fungal infections described as adverse events, without strong evidence of Cryptococcus spp. infections. IL-17A plays a crucial role in barrier immunity against fungi, and its inhibition may predispose patients to uncommon infections, as illustrated in this case. This report expands the spectrum of opportunistic infections associated with IL-17 inhibitors and suggests the need for close monitoring for atypical fungal infections in patients receiving these therapies, particularly those with additional immunosuppressive comorbidities. The case highlights the importance of early diagnosis and appropriate management of opportunistic infections in immunosuppressed patients and underscores the relevance of reporting similar cases to support future clinical recommendations.