Adverse Effects and Fatalities Associated with Subcutaneous Allergen Immunotherapy

I. INTRODUCTION Most local and systemic reactions that develop during allergen immunotherapy occur within 20 to 30 min of injection but can occur later than 30 min afterward. Subcutaneous nodules at the site of injection are more common with aluminum-adsorbed vaccines, may persist but usually disappear, and do not necessitate an adjustment in the immunotherapy dose. Patients who develop nodules that persist should be injected with aqueous preparations.