Disseminated Salmonellosis and cutaneous vasculitis in a child with IL12Rß1 deficiency – a case report & review of literature.

Mendelian susceptibility to mycobacterial disease (MSMD) is a group of genetic disorders characterized by a defect in interferon γ (IFN γ)–mediated immunity, with predisposition to infections caused by atypical and low virulent mycobacteria. We describe a 10-year-old boy, presented with left inguinal and submandibular lymphadenopathy with low grade fever for 10 days. Past history was significant and at the age of 4 months and 5 years, he was diagnosed to have tubercular axillary lymphadenitis and was treated with anti-tubercular drugs on each occasion. On examination, he had left submandibular and inguinal lymphadenopathy and mild splenomegaly. He underwent left inguinal lymph node biopsy that reported granulomatous lymphadenitis and culture reported growth of Salmonella enterica. Genetic evaluation showed pathogenic homozygous mutation of IL12Rß1 gene. A diagnosis of MSMD was established and he was treated with antibiotics to which he responded promptly. A detailed review of literature on IL12RB1 deficiency was performed. Index case has been discussed in light of the previously published literature.