T helper type 2 immune response in alopecia areata / 中华皮肤科杂志

Alopecia areata (AA) is a common inflammatory and non-scarring hair loss condition with unknown pathogenesis, and relapses are common in some patients. Evidence has demonstrated that allergy takes part in the early onset, severe condition, recurrence, and prolonged process in AA. Allergy to dust mites may be one of the reasons for refractory severe AA, especially in childhood, possibly due to the predominance of T helper type 2 (Th2) immune response. Desensitization can suppress the Th2 immune response, alter the immune balance, and reduce disease severity during AA relapses. In addition, high IgE levels may predict favorable efficacy of dupilumab in AA patients before treatment, while high interleukin-4 levels may predict the ineffectiveness of topical immunotherapy with diphenylcyclopropenone, which works by antagonizing Th1 immune response. Therefore, serum total IgE, specific IgE to dust mites, and interleukin-4 can be considered as biomarkers, revealing the predominance of Th2 immune response in AA patients. This article focuses on the relationship between allergy and AA, as well as the role of anti-allergic reactions and desensitization in the treatment of AA, aiming to provide ideas for precise and individualized treatment of AA.

Clinical features of primary cicatricial alopecia in Chinese patients.

Background: There have been few reports on primary cicatricial alopecias (PCR) especially from Asia (PCA). Aims: To study the clinical, pathological and dermoscopic characteristics of PCA among Chinese patients. Methods: A retrospective analysis of the clinical data of 59 patients with PCA was conducted and the dermoscopic, pathological, treatment and prognosis characteristics analyzed. Fisher’s Chi‑square exact test, Kruskal‑Wallis and Spearman rank correlation test were performed. Results: The ratio of neutrophilic to lymphocytic cicatricial alopecias was about 1.3:1 in this group. The most frequent disorder was folliculitis decalvans. Follicular openings were absent on dermoscopy in all cases except alopecia mucinosa. Patulous follicular openings were characterisitc of alopecia mucinosa. After treatment, an increase in short vellus hairs was the earliest feature, while telangiectasia, epidermal scale, follicular hyperkeratosis, pustules and hair diameter diversity gradually decreased or even disappeared. Improvement in the areas of hair loss after treatment was seen more often in discoid lupus erythematosus, folliculitis decalvans and dissecting cellulitis than in patients with classic pseudopelade of Brocq. Nine patients (13.6%) relapsed after cessation of therapy. Female patients needed longer treatment times. Long duration, large areas of hair loss and shorter treatment courses were the major factors in relapses. Conclusions: Dermatoscopy provides a rapid, practical and useful aid for the diagnosis of PCA and also to assess disease activity. Patulous follicular openings are a specific dermoscopic sign of alopecia mucinosa. Lichen planopilaris is less common in China than in the West.

Diffuse alopecia areata is associated with intense inflammatory infiltration and CD8+ T cells in hair loss regions and an increase in serum IgE level.

Background: Mechanism leading to an abrupt hair loss in diffuse alopecia areata (AA) remains unclear. Aims: To explore the characteristics of diffuse AA and possible factors involved in its pathogenesis. Methods: Clinical and laboratory data of 17 diffuse AA patients and 37 patchy AA patients were analyzed retrospectively. Serum IgE level was evaluated in all diffuse and patchy AA patients, as well as 27 healthy subjects without hair loss to serve as normal control. Univariate analysis was performed using Fisher's exact test and Wilcoxon rank-sum test. Associations between inflammatory cell infiltration and laboratory values were analyzed using Spearman rank correlation test. Results: The mean age of patients with diffuse AA was 27 years with a mean disease duration of 1.77 months. All of them presented in spring or summer with an acute onset of diffuse hair loss preceded by higher incidence of scalp pruritus. Although no statistically significant difference on the incidence of atopic disease among three groups has been found, serum IgE level in diffuse AA was higher than that in healthy controls, but was comparable to that in patchy AA group. Histopathology of lesional scalp biopsies showed more intense infiltration comprising of mononuclear cells, eosinophils, CD3 + , and CD8 + T cells around hair bulbs in diffuse AA group than in patchy AA group. Moreover, IgE level in diffuse AA patients positively correlated with intensity of infiltration by mononuclear cells, eosinophils, and CD8 + T cells. Conclusions: Hypersensitivity may be involved in pathogenesis of diffuse AA. The acute onset of diffuse AA may be related to intense local inflammatory infiltration of hair loss region and an increase in serum IgE level.