Seasonality in the severity of atopic dermatitis and birth season

Background Some patients with atopic dermatitis (AD) get worse in the summer and others in the winter. Birth season was suggested to be associated with the prevalence of AD in previous studies. This study aimed to explore the relationship between birth season and alterations in the severity of AD. Methods This is a pilot prospective study of 50 patients from the outpatient unit of the department of dermatology at the Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Chinese Medicine in China with one year follow-up. The scoring atopic dermatitis (SCORAD) was employed to evaluate the severity of AD. The SCORAD score and itch score were recorded at each visit. Seasonal fluctuations in AD severity were analyzed classified by birth season, as well as other potential risk factors. Results Summer was the most severe season for AD patients with summer births (with a SCORAD of 63.54 ± 9.13), compared to spring, autumn, or winter (SCORAD was 51.30 ± 17.19, 43.72 ± 13.44 and 47.04 ± 16.44, respectively) (P < 0.01). Among individuals with summer birth, the itching score was highest in the summer (P = 0.01), too. Besides, in newly onset AD, the severity of SCORAD worsened in the spring (P = 0.04). Conclusions Patients with summer birth experienced the most severe AD in summer. Interventions on exacerbations at the earliest time of onset should be implemented in this population.