Perspectives on seborrheic dermatitis: looking back to move ahead

Association of air pollution with incidence of late-onset seborrhoeic dermatitis: a prospective cohort study in UK Biobank

BACKGROUND

Late-onset seborrhoeic dermatitis seriously affects patients' quality of life. Studies have shown an association between air pollution and other inflammatory skin diseases. However, associations between air pollution exposures and the incidence of late-onset seborrhoeic dermatitis have not been elucidated.

OBJECTIVES

To investigate air pollution's role in the incidence of late-onset seborrhoeic dermatitis.

METHODS

We engaged a prospective cohort analysis utilizing the UK Biobank database. Exposure data spanning various years for specific air pollutants, namely particulate matter [PM; with an aerodynamic diameter of ≤ 2.5 µm (PM2.5), between 2.5 and 10 μm (PM2.5-10), ≤ 10 μm (PM10)] along with nitrogen oxides (NO plus NO2, denoted NOx) and NO2, were incorporated. Through a composite air pollution score constructed from five pollutants and employing Cox proportional hazards models, the relationship between air pollution and seborrhoeic dermatitis was delineated.

RESULTS

Our examination of 193 995 participants identified 3363 cases of seborrhoeic dermatitis. Higher concentrations of specific pollutants, particularly in the upper quartile (Q4), were significantly linked to an elevated risk of seborrhoeic dermatitis. Notably, PM2.5, PM10, NO2 and NOx exhibited hazard ratios of 1.11, 1.15, 1.22 and 1.15, respectively. The correlation was further solidified with a positive association between air pollution score increments and onset of seborrhoeic dermatitis. Intriguingly, this association was accentuated in certain demographics, including younger men, socioeconomically deprived people, smokers, daily alcohol consumers, and those engaging in regular physical activity.

CONCLUSIONS

Our findings revealed that air pollution exposures were associated with incidence of late-onset seborrhoeic dermatitis. These results emphasize the importance of preventing environmental air pollution exposures to mitigate the risk of developing the condition.

Seborrheic Dermatitis in Older Adults: Pathogenesis and Treatment Options

Seborrheic dermatitis is a common and chronic skin disease, which is particularly prevalent in older adults. While a specific cause of seborrheic dermatitis remains largely unelucidated, the currently understood pathogenesis of seborrheic dermatitis revolves around the presence of Malassezia yeast colonies and an inflammatory response in the affected individual. Keratinocyte proliferation resulting from inflammasome response in the host skin leads to the clinically relevant symptoms of seborrheic dermatitis. The increasing number of older adults as a percentage of the population in the USA will lead to an even higher prevalence of the disease in the ensuing decades. Fortunately, there are multiple treatment options based on individual patient situations and preferences. Topical treatment is the gold standard, but oral therapy may be required in certain cases. In order to maximize effectiveness and minimize adverse pharmacologic effects, effective treatment for older adults must take into account changes in lifestyle and metabolism that occur with aging.