From anaphylaxis to eosinophilic esophagitis during omalizumab treatment in a boy with severe asthma and food allergy: a case report

BackgroundEosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus with symptoms of esophageal dysfunction. It is strongly associated with other atopic conditions in patients and has therefore been recognized as a late manifestation of the atopic march.

Sensitization to foods and/or aeroallergens early in life may predispose some individuals to subsequent EoE development. Moreover, the disease was found to emerge as a potential side effect of oral immunotherapy (OIT).

However, it remains unclear whether OIT induces or rather “unmasks” a pre-existing but subclinical disorder.Case presentationWe report a boy with IgE-mediated cow’s milk (CM) allergy, confirmed in infancy after anaphylaxis to yogurt, positive skin prick tests, and elevated CM-specific IgE. He tolerated baked milk following a supervised oral food challenge.

From early childhood, he developed severe allergic asthma and rhinitis, refractory to standard therapy. Omalizumab (OMA) was initiated at 10 years of age with marked and sustained asthma control.

While receiving anti-IgE treatment, at 13 years of age, the patient independently liberalized his diet and tolerated progressively less processed dairy products for 6–8 months without immediate hypersensitivity reactions.