Background: Indoor allergens are common causes of sensitization and asthma. Climatic and home conditions can modify their levels.
Objective: We studied the influence of climatic conditions and home characteristics on the exposure to indoor allergens of mite allergic asthmatic subjects in two Spanish cities with different climates (Las Palmas and Pamplona).
Methods: We included 65 subjects diagnosed with asthma caused by Dermatophagoides pteronyssinus. A questionnaire about their dwellings was completed. Home dust samples were collected. Mite (Der p1, Der f1, Der 2) and cat (Fel d1) allergens were measured by a monoclonal-antibodies based ELISA.
Results: Characteristics of dwellings were similar in both areas. Der p1 was the main allergen (0-44 micrograms/g). Der p1, Der f1 and Der 2 levels were higher in the homes in Las Palmas (p < 0.001, p < 0.01 and p < 0.001, respectively). Damp homes in Pamplona had higher Der p1 levels, similar to those detected in homes in Las Palmas. Fel d1 levels (0-78.90 micrograms/g) were only related to the presence of cats in the dwelling (p < 0.001).
Conclusions: D. pteronyssinus allergen exposure was influenced by climatic conditions and dampness in homes in temperate regions. Humidity in homes can generate an ideal environment for mite growth despite unfavorable outdoor climatic conditions. Fel d1 levels were only related to the presence of a cat in the house.