Y.W.YEW1, M..LOH2, T.H.MINA2 , S.T.G.THNG1, J.C.CHAMBERS2
National Skin Centre1, Nanyang Technological University2
How to diagnose atopic dermatitis (AD) in population-based studies is debatable, especially among adults and Asians. We therefore aim to understand how various classification methods affect the reported prevalence of AD using an Asian general population cohort.
Participants of the Healthy Living in Singapore (HELIOS) cohort study from April 2018 to Jan 2020 were evaluated. Participants reported whether they have ever been diagnosed with eczema. They responded to questionnaire items of the UK Working Party (UKWP) diagnostic criteria of AD. Visible flexural dermatitis was evaluated by staff with standardized training. Prevalence of AD was analyzed based on self-reported eczema, flexural dermatitis, UKWP and its modified version (UK2/4). UK2/4 version required fulfillment of major criterion and at least 2 of 4 minor criteria (excluding criterion for flexural dermatitis).
There was a total of 5560 participants with a median age of 50.4 years old. Majority (78.5%) of participants were Chinese. Prevalence estimates of AD according to self-report, visible flexural dermatitis, UKWP and UK2/4 criteria, were 19.0±0.5%, 3.2±0.2%, 2.8±0.2% and 8.8±0.4% respectively. Kappa values between self-reported AD and (UKWP and UK2/4) were weak to fair (0.173 and 0.32 respectively).
The reported prevalence of AD varied depending on the methods used. The UKWP criteria, which include a history of atopy and early age of onset seem less sensitive for diagnosis of AD in an Asian adult cohort. UK2/4 criteria reported AD prevalence was similar to our known local prevalence of adult AD and may therefore be more appropriate.