Skin lesions in humans bitten by European pigeon tick Argas reflexus (Fab.) (Ixodida: Argasidae) massively occurring in the Upper Silesian conurbation of south-west Poland

Introduction and objective. The great number of pigeon populations in many European cities promotes the spread of the European pigeon tick (Argas reflexus), the bites of which cause local and systemic reactions. The aim was to study the occurrence of A. reflexus in several cities of Upper Silesia, and skin lesions caused by A. reflexus tick bites in humans. Materials and method. The results of investigations carried out in 1995–2002 in five cities located in the Upper Silesian conurbation are presented. Specimens of A. reflexus were collected for one hour in attics and lofts inhabited by these ticks. A history of skin lesions caused by bites was taken from residents who had been infested by A. reflexus. The development of skin lesions was monitored for three months in two individuals who had been bitten several times by these arthropods. Results. In the localities, 987 A. reflexus specimens were collected, including 334 females, 269 males, and 384 various nymphal stages. Within one hour, 38–109 ticks specimens were collected at the study sites. Cases of attacks by unengorged A. reflexus were reported in all the habitats located in the residential buildings; the ticks were also found in residents’ flats and in staircases. Residents who had been repeatedly attacked by European pigeon ticks developed a strong inflammatory reaction to the components of tick saliva, and had purple papules with necrosis in the centre of the lesion. The tick bite areas exhibited scars and hyperpigmentation. Conclusions. Individuals attacked by A. reflexus several times are at risk of development of severe persistent local reactions to bites. Pigeon ticks, trophically associated with pigeons present abundantly in the Upper Silesian conurbation and other European urban habitats, pose a serious threat to public health.