A case report of diet elimination guided by food specific IgG4 achieved clinical cure for eczematous external otitis with finger paronychia.

ABSTRACT

RATIONALE Eczematous external otitis (EEO) is the most difficult-to-treat otitis externa, and characterized by the symptoms of inflammation with hypersensitivity of the external ear canal skin. It is acknowledged as a chronic skin inflammation primarily caused by dermatological and allergic reactions. Food allergens are also considered a cause to induce the inflammation. However, the role of food specific IgG4 in this disease is unclear yet. PATIENT CONCERNS A 54-year-old woman complained of recurrent itching of the external auditory meatus for 3 years and nails chapping of hands for 2 years. DIAGNOSES AND INTERVENTIONS: She was diagnosed with EEO and underwent the therapeutic strategy as food elimination of egg, milk and wheat, guided by the result of food specific IgG4 together with probiotics on the basis of previous symptom controlling therapy. OUTCOMES: After 17 months' treatment, she was finally free of all the symptoms and the serum IgG4 specific to all foods are under normal limit. LESSONS To the best of our knowledge, it is the first report revealing the clinical significance of food specific IgG4 in EEO, and the successful treatment with diet elimination guided by food specific IgG4 threw a new light on the clinical management of refractory EEO.