Ultraviolet Sun Exposure Is Associated with the Acute Symptoms of Atopic Dermatitis in Young Children
Sunday, March 6, 2016
South Exhibit Hall H (Convention Center)
Kangmo Ahn, MD,PhD, Jihyun Kim, MD, Hyunyoung Jeon, Hyunmi Kim, Youngshin Han, PhD, Kwon Jung, Sumi Eo, Mijin Ahn, Young-Min Kim
Rationale: We evaluated the association between sun exposure and atopic dermatitis (AD) symptoms in children in a longitudinal study.

Methods: Eighty two infants and young children (48 boys and 34 girls aged under 6 years) with AD living in Seoul, Korea were enrolled and followed for 17 months between August 2013 and December 2014. Daily AD symptoms were recorded to describe the degree of itching, sleep disturbance, erythema, dryness, oozing, and edema with a scale of 0 to 4. We assessed ultraviolet (UV) sun exposure by measuring radiation heat fluxes for 290-400 nm wavelength range using a thermopile. Generalized linear mixed model was used to evaluate the effect of UV on the AD symptom controlling for age, sex, seasons, outdoor temperature, outdoor humidity, ambient particulate matters and nitrogen dioxide.

Results: Symptom records of 17,602 person-days were analyzed. UV showed significantly positive relationship with AD symptoms. An increase in daily UV by 10 W/cm2 was associated with an increase in 1.8% (95% CI: 1.3-2.4) of AD symptoms on the same day and an increase in six days of moving averaged UV by 10 W/cm2 with 4.4% (95% CI: 3.5-5.2) of AD symptom increase. The effect of UV was most harmful in fall showing 3.8% increase of AD symptoms per 10 W/cm2 of UV increase, whereas 3.2% decrease of AD symptoms was found in winter. Boys were more sensitive to UV than girls.

Conclusions: Our data suggest that exposure to ultraviolet light is associated with AD symptoms in children.