The Clinical Features Of Atopic Dermatitis: A Study Of 3915 Patients From China

Background Atopic dermatitis (AD) is a common, chronic relapsing, inflammatory skin disorder affecting mostly infants and childhood. Most of the large-scale epidemiological studies are based on the Western population. This study was a retrospective design of 3915 Chinese Han AD patients, both epidemiological and clinical profiles commonly associated with AD were studied.Objective The aim of this study was to present the clinical and epidemiological profiles of Chinese Han patients with AD.Methods Data of 3915 AD patients who fulfilled the diagnostic criteria of Hanifin-Rajka were collected from hospitals located in multiple cities in China from January 2008 to March 2010. All AD patients or their parents were questioned in detail using identical questionnaire. Statistical analysis was performed using EPI INFO 6.0 (Centers for Disease Control and Prevention, Atlanta, GA, USA) and SPSS10.0 (SPSS Inc, Chicago, IL, USA). Differences of clinical and epidemiological profiles in relation to ages of onset and gender were evaluated by Pearson Chi-Square test.Results The median age of onset was two months, with a male-to-female ratio of 1.5 :1 (male 2333, female 1582), 3313 (84.6%) started AD before 2 years old, and more males were affected in early AD group. A positive family history of atopy was seen in 2778 (71%) patients.'Pure'AD was noted in 2267 (57.9%), and 1648 (42.1%) patients suffered from a'mixed'type. Our data indicated the prevalence rate of family history of atopy was higher in early AD group, however the prevalence rates of asthma and allergic rhinitis (AR) were lower in early AD group (all p < 0.001). Additionally, seasonal variation of AD was observed in 53.0% of patients, and 47.0% had no evident seasonal variation. Of the 3915 AD patients, 84% AD patients were mild to moderate disease, males group appeared to have more severe involvement (p < 0.05). Minor signs of Hanifin-Rajka diagnostic criteria such as xerosis (78.0%), itching while sweating (64.9%), and facial pallor/erythema (58.4%), and of the five additional features, scalp dermatitis (44.1%), infra-auricular and retroauricular fissuring (33.9%) and chronic scalp scaling (22.4%) were more commonly seen. Our data indicated that the frequencies of facial pallor/erythema, scalp dermatitis, infra-auricular and retroauricular fissuring, nipple eczema, and xerosis, were higher in early AD group, whereas the frequencies of orbital darkening, pityriasis alba, icthyosis/ keratosis pilaris/ palmer hyperlinearity, and Dennie-Morgan fold, were higher in onset age≥2 years group (all p < 0.05). Additionly, the frequencies of facial pallor/erythema, tendency to skin infections, and nipple eczema were higher in males, but orbital darkening, Dennie-Morgan fold, and icthyosis/ keratosis pilaris/ palmer hyperlinearity, were more common in females (all p < 0.05).Conclusion Differences of the severity of disease, clinical and epidemiological profiles in relation to ages of onset and gender were statistically significant, which provide clues to describe Chinese Han AD patients.