The researchers have done a survey based on southwest Colombia. During the study in the remote areas, it became apparent that a high percentage of the population suffered from chronic pruritus in association with high numbers of ticks and tick bites. The main objective of the study was to determine the clinical features and severity of tickbite‐associated pruritus. At two time points – 8 weeks apart to account for seasonal effects – a cross‐sectional study was conducted encompassing physical examination of the population, histological analysis of skin biopsies, and determining serum for antibodies against spotted fever (SFG) rickettsiae and typhus group (TG) rickettsiae. The researchers identified ticks using morphological criteria, and PCR determined infection by rickettsiae.
About 94.5% of the population (95% CI 92–97%) showed clinical signs of a pruritic arthropod reaction and chronic pruritus with lichenoid papules and hyper‐ and hypopigmented nodules on otherwise noninflamed skin. Pruritus markedly impaired the quality of life in terms of sleep disturbances. They did not observe any signs of other diseases. Chronic pruritus appeared to be because of repeated tick bites and scratches, but not because of other dermatological or medical conditions. Antibodies against SFG and TG‐rickettsiae were detected at 79.0% and 3.6%, respectively. Ticks were identified as Amblyomma cajennense.