Allergy to dust mites may contribute to early onset and severity of alopecia areata

Summary Background A higher risk of allergic diseases such as rhinitis, asthma and atopic eczema (atopic dermatitis) has been reported for patients with alopecia areata (AA) compared with the general population, but the significance of this is still largely unclear. Aim To determine whether serum total or specific IgE play a role in the onset and severity of AA. Methods We tested 461 serum samples from 351 patients with AA and 110 healthy controls (HC) for total IgE (tIgE) and specific IgE (sIgE) by ImmunoCAP-100 or in vitro test (IVT). Results The absolute value of tIgE was higher in patients with AA than in normal controls (P   120 IU/mL) detected in patients with AA (29.3%) was similar to that of HC (21.8%). Prevalences of raised sIgE against various allergens detected by ImmunoCAP-100 showed that Dermatophagoides pteronyssinus (Der p; 31.1%) and Dermatophagoides farinae (Der f; 29.0%) were the most common allergens. Similar results were found by IVT, with the most common response being against Der p/Der f (29.0%). However, the prevalences of tIgE and sIgE against dust mites (Der p and Der f) in patients with early-onset AA and severe AA were significantly higher than those with late-onset AA and mild AA (P = 0.02, P = 0.02 vs. P = 0.03 and P = 0.001, respectively). Notably, the increases in tIgE and sIgE were independent of atopy history. Conclusions Allergy to dust mites may have an effect on the immune response in AA, and may contribute to its early onset and severity in patients of Chinese origin.