Sensitization according to skin prick testings in atopic patients with asthma or rhinitis at 24 allergy clinics in Northern Europe and Asia

Abstract

Skin prick tests (SPT) were performed on 2113 atopic patients (407 children and 1 706 adults) with asthma and/or rhinitis at 24 allergy clinics in Iceland, Norway, Denmark, Sweden, Estonia, Lithuania and Russia. Test extracts were Dermatophagoides pteronyssinus ( D . pteronyssinus), Dermatophagoides farinae [D. farinae), cat, dog, horse, birch, timothy, mugwort, Cladosporium, Alternaria, cockroach, chironomids (red mosquito larvae, RML) and shrimp. Among the allergens, timothy followed by cat, birch and dog gave the highest number of positive SPT. Positive SPT with house dust mites (HDM), furred animals, RML and Cladosporium were more common in asthmatics than in patients with rhinitis; birch and timothy more common in patients with rhinitis. Sensitization against D. pteronyssinus, horse, timothy and Cladosporium was more common in men than in women. Although the general sensitization pattern of the atopic patients at the participating centers showed similarities, there were also significant differences between centers. Positive SPT with furred animals were most prevalent in Northern and Central Sweden and St Petersburg, and least common in Siberia and Denmark. Pollen allergy was most common in Novosibirsk and on the west coast of Sweden, and less common in Vladivostok. Sensitization against HDM was most common in Lithuania and least prevalent in Northern Sweden and Finland. Insect allergens gave the most positive reactions in St Petersburg and the least positive reaction in Novosibirsk. Sensitization against multiple allergens was found in 74% of the patients and a mono-allergy in 26%. The degree of atopy was higher in males than in females and higher in asthmatics than in patients with rhinitis. The month of birth of the patients did not influence significantly the test results. It is concluded that although the sensitization pattern shows similarities in different regions, it is also influenced to some extent by residence as well as by diagnosis, sex and age of the patients.