Skin disease prevalence varies with seasons

Some skin diseases present with seasonal patterns, including warts, eczema, and atopic dermatitis, a new study has found. Though more common in winter, acne remains the most prevalent diagnosis in dermatology clinics.

Researchers conducted a cross-sectional study of 3,120 patients (mean age 35.24±15.62 years, 64.13 percent women) visiting the dermatology clinic of Razi hospital in Iran. Disease prevalence was assessed according to meteorologically defined seasons and patient information were retrieved from medical records.

Across all seasons, women presented to the dermatology clinic more than men at around twice the rate. In terms of age, those 31–45 years old were referred more frequently than other age groups, except in autumn, when 16–30-year-olds arrived at the clinic more frequently. Overall, winter (34.39 percent) saw the greatest proportion of visits, while autumn (19.43 percent) had the lowest.

Acne emerged as the most prevalent diagnosis (14.64 percent), followed by psoriasis (7.24 percent), eczema (5.61 percent), and nongenital warts (4.81 percent).

Marked seasonal variations in disease prevalence were also observed. For instance, acne, eczema, dermatophytosis, lentigo, vitiligo, warts, nevus, and seborrheic dermatitis were all significantly more frequently detected during winter (p<0.05 for all). In comparison, atopic dermatitis was associated with spring and winter (p<0.05), while actinic keratosis and lichen planus peaked in summer (p<0.05).

Notably, dermatological infections were significantly more common in winter vs summer (p=0.001).

“Seasonality of skin disease has been explained by monthly alterations in ultraviolet radiation that regulates the inflammatory skin processes,” the researchers said, adding that bacterial type and load on the skin also varied throughout the year.