Virus-associated immune dysregulation presenting as facial granulomatous dermatitis in DiGeorge syndrome: A case...

Chronic granulomatous dermatitis in children with inborn errors of immunity poses diagnostic challenges, particularly when persistent viral detection coexists with impaired T-cell surveillance. We report two children with 22q11.2 deletion syndrome who developed chronic facial granulomatous dermatitis in the setting of T-cell immunodeficiency and EBV detection. Both patients had persistent facial plaques refractory to conventional antimicrobial or anti-inflammatory treatment, elevated EBV DNA in blood and granulomatous lymphohistiocytic infiltrates on skin biopsy. Tissue mNGS identified EBV in lesional specimens. In patient 1, EBER positivity and a restricted/skewed TRB repertoire provided stronger support for local EBV-associated immune dysregulation. In patient 2, EBV was detected by mNGS, but EBER staining was negative, additional microorganisms were identified, and TRB findings were more consistent with reactive or oligoclonal expansion, making causal attribution less certain. Rubella virus-associated granuloma, a key differential diagnosis in immunodeficient children, was not supported by lesion-directed testing. These cases highlight chronic granulomatous dermatitis as a possible manifestation of virus-associated immune dysregulation in DiGeorge syndrome and emphasize that mNGS results require careful integration with tissue localization, histopathology, clonality assessment, and immune context.