Mammalian meat allergy is a delayed immunoglobulin E (IgE) mediated hypersensitivity reaction to galactose-alpha-1,3-galactose (alpha-gal). Alpha-gal is an oligosaccharide present on glycoproteins and glycolipids of nonprimate mammals as well as biologic agents prepared using mammalian cells including infliximab. We describe a pediatric patient with Crohn’s disease who developed urticaria and pruritus roughly 6 hours after her very first infliximab infusion that progressed to chronic urticaria following subsequent infliximab infusions. She was diagnosed with mammalian meat allergy based on an elevated serum IgE level directed against alpha-gal. Her symptoms resolved once infliximab infusions were discontinued and did not recur after commencing therapy with adalimumab.

Autologous fecal transplant (AFT, transfer of ileostomy feces to the colon) for diversion colitis (DC) has not yet been described in children or adolescents. We performed serial AFTs in a 16-year-old with Crohn’s disease and DC. As evidenced by endoscopic, histologic, laboratory, and multiomic profiling of the colon, the first AFT led to interval improvement in DC, whereas the second AFT reactivated Crohn’s colitis. These findings ultimately guided shared decision-making towards total colectomy.