Overall Seasonal Variation of Psoriasis Is Limited With Distinctive Clinical Subsets

Little overall seasonal variation of psoriasis was discovered in a recent systematic review, but distinctive subsets were observed with improvement in the summer or winter, according to a study published in Skin Research and Technology.

Researchers aimed to systematically review literature on psoriasis and seasonal variation in Northern and Central Europe with studies grouped before and after topical steroid, and later systemic treatment introduction. Literature searches were performed using the PubMed, EMBASE, and BIOSIS databases. Manual searches of old reports before the introduction of efficient modern therapies were also performed.

Of the 13 studies enrolled, 50% of patients with psoriasis were stable and showed no difference between seasons. Around 30% improved in the summer and 20% improved in the winter. Some patients worsened in the summer. These European results were consistent with matched international reports.

“In conclusion, the classical literature on psoriasis and season collected before modern therapies were introduced indicated no seasonal variation of psoriasis,” wrote the study authors. “Recent literature limited to Northern and Central Europe indicates that the seasonal effect on psoriasis has three clinical subsets: About 50% are not influenced by season, approximately 30% improve during summer, and about 20% do better in winter,” they added.

Reference
Jensen KK, Serup J, Alsing KK. Psoriasis and seasonal variation: a systematic review on reports from Northern and Central Europe—little overall variation but distinctive subsets with improvement in summer or wintertime. Skin Res Technol. 2022;28(1):180-186. doi:10.1111/srt.13102