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 I g E 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 I g E (t I g E ) and specific I g E (s I g E ) by I mmuno CAP ‐100 or in vitro test ( IVT ). Results The absolute value of t I g E was higher in patients with AA than in normal controls ( P  < 0.001), although the prevalence of raised t I g E (> 120 IU/mL) detected in patients with AA (29.3%) was similar to that of HC (21.8%). Prevalences of raised s I g E against various allergens detected by I mmuno CAP ‐100 showed that D ermatophagoides pteronyssinus ( D er p; 31.1%) and D ermatophagoides farinae ( D er f; 29.0%) were the most common allergens. Similar results were found by IVT , with the most common response being against D er p/ D er f (29.0%). However, the prevalences of t I g E and s I g E against dust mites ( D er p and D er 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 t I g E and s I g E 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 C hinese origin.