Distinct clinical feature and serum cytokine pattern of elderly atopic dermatitis in China.

Background Elderly atopic dermatitis (AD) is a newly defined subtype of AD stratified by age-related clinical pictures. Objectives To analyse the clinical features and molecular profile of elderly AD patients in China, comparing with infantile, childhood and adolescent/adult AD. Methods A total of 1312 patients diagnosed by Hanifin and Rajka diagnostic criteria of AD from Huashan Hospital, Shanghai, China, were divided into four groups by age (2-18, 19-40, 41-60 and >60 years), and clinical features were evaluated by questionnaire and physical examination. Serum total IgE, eosinophil counts and various cytokines were further analysed in some of the patients and healthy controls. Results Elderly AD showed significantly higher male/female ratio and rural/urban ratio than other age groups, and more than half of elderly AD first appeared after 60 years old. Skin lesions of elderly AD were more often seen in the trunk and extensor sites of the extremities. Level of serum IgE and eosinophil counts were significantly lower in elderly AD than those in other age groups. Serum levels of IL-4, TARC, IL-17A, IL-6, IL-22, IL-33 and TSLP were significantly higher in elderly AD patients than those of healthy controls, indicating a mixed Th2/Th17/Th22 inflammation. Conclusions Elderly AD demonstrated unique clinical characteristics compared with other age groups and showed mixed Th2/Th17/Th22 skewing, indicating a unique pathogenesis for elderly AD.