PD40 - A successful desensitisation to cat in a child with anaphylaxis

Case report He was referred with a history of suddenly occurring sneezing, urticaria, respiratory distress, wheezing and sometimes hypotension within 30 minutes after contact with cats. He had experienced those symptoms more than five times with a variety of severity in last two years. His past medical history was insignificant for asthma or any of atopic diseases. Allergen specific IgE against cat was 24 kUA/L, and negative against dog and other furred animal dander by ImmunoCAP assay (Phaida Diagnostics, Uppsala, Sweden). Skin prick test (SPT) was 5 mm for histamine, 11 mm for commercial extract of cat dander and negative for other animal dander and pollens. With regard to unconvincing history, an open challenge test was performed at hospital setting. Anaphylactic reaction with sneezing, rhinorrhea, diffuse urticaria, coughing and mild hypotension developed within 20 minutes after exposure to cat. A subcutaneous immunotherapy protocol was designed with a built-up phase of 6 months. He had no systemic reaction during immunotherapy except large local allergic reactions at injection site at built-up phase. He was evaluated for desensitization at the first year of immunotherapy by a skin prick test and provocation test without any local or systemic allergic reactions. Conclusion For the first time, by presenting this case anaphylactic reactions mediated by exposure to airborne cat allergens is demonstrated to underline the causative role of inhalant allergens in development of anaphylaxis. Moreover, a successful desensitization to cat allergens in a child with anaphylaxis was established in the first year of immunotherapy.