Snapshot A 7-year-old presents to the pediatrician with a “white tongue.” On physical exam, he has notable thrush in his oral mucosa. His past medical history includes chronic diaper rash as a baby. It is otherwise unremarkable. Physical exam shows malformed nails on two fingers, consistent with onychomycosis. Labs are within normal limits. He is started on fluconazole. Introduction Primary immunodeficiency from dysfunction of T-cells Recurrent infections with noninvasive Candida albicans May also be susceptible to other bacterial and viral infections Genetics familial autosomal recessive sporadic autosomal dominant Pathogenesis absent T-cell proliferation autoimmune regulator deficiency (AIRE) Associated conditions autoimmune diseases notably endocrinopathies Presentation Symptoms due to C. albicans infection of the following skin oral mucosa thrush nails diaper area in infants Evaluation All patients should be evaluated for other immunodeficiencies CBC (normal in chronic mucocutaneous candidiasis [CMC]) Ig levels (normal in CMC) Absent in vitro response of T-cells to Candida antigen Absent cutaneous reaction to Candida antigen Genetic testing for mutations Differential Diagnosis SCID Immunodeficiency caused by HIV Treatment Chronic therapy with fluconazole Prognosis, Prevention, and Complications Prognosis normal Complications severe lung infections sepsis