Background: Dermatophagoides is one of the most common inhalant allergens in the pathogenesis of atopic dermatitis (AD). The prevalence of atopic patch test (APT) to it in the general population, however, is largely unknown.
Objectives: The aim of this study was to detect the frequency of APT to Dermatophagoides in a self-selected population in Beijing.
Methods: Healthy university student volunteers were recruited and patch tested with a commercial Dermatophagoides (pteronyssinus/pharinae) mix.
Results: Of 201 students studied, 25.9% exhibited positive results. The positivity rate was not correlated to gender but increased with age. In volunteers without eczema, allergic rhinitis, or asthma, the positivity rate of APT was as high as 13.6% but is much lower than that of volunteers who had allergic rhinitis or asthma (56.1%, P < 0.05, χ2 test). One volunteer had AD and was tested positive, but only 27.3% of those who had other types of eczema but without allergic rhinitis or asthma were tested positive.
Conclusions: This study confirmed that APT to Dermatophagoides mix is highly related not only to AD but also to respiratory allergy. The high positivity rate of APT in volunteers without eczema or respiratory allergy implied that a large number of positive APTs in patients with AD may be not relevant.