Anaphylactic shock after pigeon tick bite.

The authors report 12 cases of anaphylactic shock occurring after pigeon tick bite (Argas reflexus). These cases were characterized by sudden onset of severe symptoms, consisting of mucocutaneous (12 cases), respiratory (8 cases), gastrointestinal (6 cases), and cardiocirculatory (12 cases) manifestations, resulting in loss of consciousness in 8 cases and requiring intensive care in 8 cases. Two types of reaction secondary to Argas reflexus bites have been described: toxic reactions and IgE-mediated anaphylactic reactions (urticaria, angioedema, anaphylactic shock, often recurrent). The diagnosis is based on the clinical history: history of a bite, generally occurring at night, during summer, presence of pigeons in the immediate environment, identification of the parasite, and is confirmed by serum IgE assay specific for Argas reflexus (class greater than or equal to 3 in 8 out of the 9 cases in which it was performed). Argas reflexus is a soft tick belonging to the order of house dust mites. It is a specific blood-sucking parasite of pigeons, mainly city pigeons. These ticks live inside houses, especially in old urban housing and on higher floors due to the presence of pigeon colonies, and can bite humans, inducing anaphylactic reactions. The allergens are presumed to be anticoagulant substances present in saliva. Curative treatment consists of the treatment of anaphylactic shock and preventive treatment is based on suppression of pigeons, their nests and their parasites, Argasides.