[A localized reaction to sublingual immunotherapy]

An otherwise healthy 31-year-old woman with allergic rhinoconjunctivitis developed considerable swelling of the floor of her mouth after sublingual allergen-specific immunotherapy with the hyposensitization product 'Slit One grass pollen'. After discontinuation, complaints disappeared and she was successfully put on a regimen of subcutaneous immunotherapy. Despite a lack of reports of serious adverse reactions in clinical trials, the Inspectorate of Health Care and The Netherlands Pharmacovigilance Centre Lareb received several reports of sometimes serious localized reactions to oral and sublingual allergen-specific immunotherapy. Under-reporting is likely since local reactions are more or less expected. Caution should be exercised with allergen treatment, even in the case of non-invasive administration.