Home-based, slow up-dosing oral immunotherapy for hen's egg allergy in an adult patient

Standard therapy for food allergies involves avoiding causative foods until a patient has outgrown their allergies. Oral immunotherapy (OIT) is an optional treatment for children unlikely to outgrow their food allergy. However, information about OIT in adult patients with food allergies is very limited. We present a case of severe hen's egg allergy (HEA) in an adult who tried home-based, slow up-dosing OIT, reported to have been tolerable and effective in children. A 20-year-old woman with HEA experienced repeated anaphylaxis since childhood when she consumed a small quantity of hen's egg, so she completely avoided hen's eggs. She underwent inpatient oral food challenge (OFC) with 10-g boiled egg yolk and presented lip swelling and abdominal pain. OFC with 1-g boiled egg yolk the following day induced no adverse reaction. OIT was initiated using a home-based, slow up-dosing protocol. She consumed 1 g of boiled egg yolk at home every day, increasing this by 5%-10% every 2 weeks. She started 0.5-g boiled egg white after reaching a whole egg yolk. If adverse reactions occurred, the daily dose was decreased. After 59 months, she was able to eat an entire boiled egg. Anaphylaxis occurred 3 times during OIT due to accidental consumptions of egg products or insufficient heating of egg. Home-based, slow up-dosing OIT might be applicable for adults with severe HEA. It should be performed with appropriate equipment and education for patients, in case of emergency.