Eosinophilic gastroenteritis and eosinophilic dermatitis in a patient: two sides of the same coin?

A female in her late 60s presented to hospital with a 2-week history of epigastric pain, nausea and vomiting. Over the past 15 years, she had 3 episodes of severe epigastric pain accompanied by a rash, all improving with short courses of prednisone. She also had a history of hypogammaglobulinaemia suspected to be due to protein-losing enteropathy. On examination, an erythematous, pruritic rash was noted on her left thigh. Laboratory studies revealed peripheral blood eosinophilia and hypoalbuminaemia. Gastroscopy and targeted biopsies showed increased eosinophilic infiltration in the foregut consistent with eosinophilic gastroenteritis (EGE). A punch biopsy of the rash showed eosinophilic infiltration in the dermis layer consistent with eosinophilic dermatitis. She was started on a tapering course of oral prednisone 40 mg daily and a proton pump inhibitor (PPI) 2 times per day. Her abdominal symptoms resolved within 48 hours. A follow-up gastroscopy 12 weeks later showed mucosal and histological improvement, and the rash subsequently improved.