[Safety of venom immunotherapy in patients pretreated with antihistamines--a retrospective study]

Immunotherapy is the only effective method of treatment of allergy to Hymenoptera venom. Pretreatment with antihistamines diminishes the incidence of adverse reactions (AR) such as large local and mild systemic reactions but it is suggested that it may mask a development of serious allergic reactions. The aim of the study was a retrospective evaluation of the incidence and nature of AR during venom immunotherapy in patients receiving pretreatment with antihistamines in the Department of Pneumonology and Allergy of the Medical University of Lodz.

50 patients started "ultra-rush" immunotherapy in our center, 8 were taken in our care after the initiation phase had been conducted elsewhere. During the dose increase phase 10 systemic adverse reactions were observed. 50% of them were only subjective and the rest mild objective reactions. During the maintenance phase 10 systemic reactions were noted, among them 2 cases of the anaphylactic shock. The incidence of systemic adverse reactions was 1 per 86 injections. Late as well as unusual reactions appeared twice.

Venom immunotherapy combined with pretreatment with antihistamines is safe. A vast majority of systemic adverse reactions is of subjective and mild objective nature and appropriate treatment leads to containment of severe reactions.