Posaconazole treatment of extensive skin and nail dermatophytosis due to autosomal recessive deficiency of CARD9.

IMPORTANCE Deep dermatophytosis is a disease that involves dermatophytic infection of the dermis and/or lymph nodes and sometimes the central nervous system. Autosomal recessive deficiency of the CARD9 (caspase recruitment domain 9) protein has been described in 17 patients with deep dermatophytosis from Algeria, Tunisia, and Morocco. OBSERVATIONS We report a case of extensive dermatophytosis due to autosomal recessive CARD9 deficiency in a patient of Egyptian origin. This patient had extensive superficial Trichophyton rubrum infection of the skin and nails without significant visceral involvement. Treatment with posaconazole was well tolerated and induced a complete clinical remission within 3 months that continued for 8 months of follow-up. CONCLUSIONS AND RELEVANCE This case report underlines the phenotypic variability of dermatophytic infection in patients with CARD9 deficiency and the potential efficacy of posaconazole for this indication.