Rare encounter of Hirschsprung’s disease and <i>CARD11</i> mutation: A diagnostic challenge

Introduction: Hirschsprung’s disease (HD), a congenital condition characterized by aganglionosis, is associated with enterocolitis, which requires repeated antibiotic exposure to drugs associated with drug-induced lupus (DIL). Drug-induced lupus mimics systemic lupus erythematosus (SLE) but typically resolves upon discontinuation of the triggering medication. CARD11 is essential for lymphocyte signaling and immune regulation, and its mutations are associated with immune disorders. Case Report: A five-year-old male with HD and Hirschsprung-associated enterocolitis (HAEC) developed symptoms of DIL, including malar rash, fatigue, while taking cephalexin. During the evaluation, the patient tested positive for SLE-associated autoantibodies and a CARD11 mutation, making it difficult to determine the origin of the symptoms. Resolution of symptoms and laboratory abnormalities after stopping cephalexin administration made DIL the probable cause. Conclusion: Through this case, we hope to further elucidate the connections between HD, DIL, and CARD11 mutation and demonstrate the diagnostic challenge with genetic mutations in the context of autoimmune dysfunction.