Seasonal aggravation of acne in summers and the effect of temperature and humidity in a study in a tropical setting

Background Effect of seasonality on acne and acne flare has varied interpretations depending on the geographical area of study. In tropical areas, factors like high temperature and humidity may cause acne flares. Aims To assess the seasonal variation of acne in patients and to correlate it with the monthly temperature and humidity over a period of 1 year. Methods A cross-sectional study of acne patients was conducted for one year. The patient's acne was graded. Patients were specifically questioned about aggravation, improvement, or no change in their acne with respect to the seasons. The mean temperature and humidity of each month in Delhi were compared with grade of acne. This variation in acne was correlated with the temperature and humidity. A P-value < 0.05 was considered as statistically significant. Results Out of 171 patients, 82 (47.95%) patients reported seasonal variation in their acne. Among them, 69 patients (40.4%) reported aggravation in summer. Eleven (6.42%) and 2 (1.16%) patients reported aggravation in winter and rainy season, respectively. The aggravation in summer as compared to rainy and winter season was statistically significant. The mean temperature and mean humidity significantly varied with seasonal aggravation of acne. Conclusions Both temperature and humidity have a contributing role in pathogenesis of acne and are causes of acne flare. In our study, aggravation of acne was more in summer and rainy season.