Physical activity as a potential nonpharmacologic strategy to prevent seborrheic dermatitis: a cohort study in the UK...

Seborrheic dermatitis (SD) is a chronic inflammatory skin disease with limited long-term treatment options. The association between physical activity and incident SD, as well as the potential mediating role of depressive symptoms, remains unclear.

To investigate the association between physical activity and incident SD and to assess whether depressive symptoms mediate this relationship.

Data from 396,903 participants in the UK Biobank were analyzed. Cox proportional hazards models were used to examine the association between physical activity and incident SD. Regression-based mediation analyses were performed to quantify the extent to which depressive symptoms mediated this association.

Physical activity above the recommended minimum (≥600 MET-min/week) was associated with a lower risk of incident SD. The greatest risk reduction was observed at 3-5 times the recommended level (1,800-3,000 MET-min/week; HR 0.80, 95% CI 0.71-0.90). Participants meeting criteria for healthy physical activity had a 28% lower risk of incident SD (HR 0.72, 95% CI 0.64-0.81). Mediation analyses showed that 17% of the protective association was explained by reduced depressive symptoms (indirect HR 0.83, 95% CI 0.77-0.88), while 16% was attributable to the direct effect of physical activity (direct HR 0.84, 95% CI 0.77-0.93).

Physical activity may serve as a non-pharmacologic strategy for the prevention of SD, partly through alleviating depressive symptoms. The maximal benefit was observed at 3-5 times the recommended minimum activity level.