[Relative potency of allergenic extracts from mites in patients with asthma and allergic rhinitis].

BACKGROUND Skin tests for specific diagnosis of allergies require high quality extracts, which can be measured by the determination of allergenic potency, utilizing different concentrations of extracts from a manufacturer. OBJETIVE To compare allergenic mite extracts manufactured by laboratories in Spain, Argentina, and Cuba by skin prick test response. METHODS A cutaneous puncture was performed on 56 patients aged 2 to 15 years with asthma and allergic rhinitis with extracts of Dermatophagoides pteronyssinus (Dp), Dermatophagoides farinae (Df), Dermatophagoides siboney (Ds) and Blomia tropicalis (Bt) produced by DIATER (Argentina), ALK- AbellÛ (Spain) and BIOCEN (Cuba). RESULTS In 84.6% of patients there was an association of symptoms with seasonal changes and house dust exposure. The diameter of wheals from ALK allergen extract was larger than extracts from other sources, but without any significant difference (p > 0.05). The ratio between wheals and allergen concentration with BIOCEN products showed lineal dependence between the diameter averages and the concentration logarithm, ranging from 4000 to 100 000 UB/mL. The skin prick tests with diameters =3mm showed a larger proportion of Dp and Df from ALK in comparison to BIOCEN and DIATER. CONCLUSIONS We found that dust mite extracts produced and standardized by DIATER, ALK-Abello and BIOCEN were similar with respect to allergenic potency.