ANAPHYLACTIC REACTIONS TO PIGEON TICKS

We report on two patients who noticed several nocturnal stings with ma ssive local reactions during May/June and August/September in the year s 1988 and 1989; at the ictus site a knot developed, which lasted abou t three months. Since 1990 both patients had several anaphylactic reac tions during the night in spring and autumn. The patients would wake u p and 5-10 min later would notice heatwaves, generalized erythema and pruritus, urticae, angioedema, diarrhoea, vomitting, tachycardia, and shortness of breath. Finally short episodes of unconsciousness occurre d in one patient. Following the sting the patients noticed weakness, p ain in muscles and joints which lasted for about three months. The his tory showed that the patients apartment?ent was located directly under the rooftop of an old renovated house, where pigeons had previously l ived. During the night, the patients found small, match-head sized, fl at and oval arthropods, which were identified as Argas reflexus (pigeo n ticks, soft ticks) in our zoological institute. Skin testing (rubbin g, prick) and RAST showed an IgE-mediated hypersensitivity (positive s kin-tests, RAST 2.2 and 3.3) to Argas reflexus. Our cases document tha t the infestation of pigeons with pigeon ticks may lead to clinical pr oblems for humans living in infested houses. If the pigeon ticks lose their natural host for a longer time, i.e., because of construction, t hey may start to attack humans at night. Stings of pigeon ticks may re sult in local reactions but also in immediate type hypersensitivity le ading to life-threatening anaphylactic reactions. The activity of thes e ticks at nigth depends on the temperature. Their painless sting, the short stay on the human body (about 30 min), the hidden way of living , the long distances pigeon ticks may migrate through several rooms, a nd their ability to hunger makes it difficult to detect and eradicate them.