Foreign-body reaction due to incorrect injections of allergen extracts containing aluminum hydroxide gel

Abstract

Background. – Subcutaneous allergen immunotherapy is considered as effective and safe in allergic patients. Although mild local cutaneous reactions occur frequently, the development of persistent nodules at the injection site is a rare event. We describe a case with unusual persistent nodular reactions at the sites of previous immunizations incorrectly performed via the intradermal route. Case. – A 42-year-old female presented with multiple persistent lesions on both forearms that appeared after allergen immunotherapy. Immunotherapy with an aluminum hydroxide-adsorbed mite extract had been started 3 years earlier. Prescription of immunotherapy and injections of the extract were performed in a rural private medical facility, under the supervision of a physician with no special allergy training; injections had been given erroneously intradermally rather than subcutaneously. Physical examination revealed multiple reddish, indurated cutaneous nodules at the injection sites. The diagnosis of a foreign-body granulomatous reaction was confirmed by histological examination of the lesions. Conclusions. – Intradermal injections of aluminum hydroxide-containing allergen extracts should be strictly avoided. This case emphasizes published international recommendations according to which specific allergen immunotherapy should be prescribed only by allergy specialists in order to avoid unsuitable indications and methods that can sometimes result in serious side effects.