This is a questionnaire study of 12 323 students done over a 1-year period, comprising 7 year olds (4605), 12 year olds (3940) and 16 year olds (3778) from 19 primary and 17 secondary schools randomly selected in Singapore. All children had a complete cutaneous examination. The diagnosis of
atopic dermatitis was based on the U.K. Working Party diagnostic criteria. The questionnaire was translated into Chinese and both the English and Chinese versions were issued simultaneously to the students.
RESULTS: The 1-year period prevalence of
atopic dermatitis was 20.8%.
Atopic dermatitis was present in 22.7% of 7 year olds, 17.9% of 12 year olds and 21.5% of 16 year olds. The overall sex ratio was equal. There were slightly more boys with
atopic dermatitis among the younger children (6 and 12 year olds, 1.18 : 1 and 1.19 : 1, respectively) but more girls were affected (1.57 : 1) among the 16 year olds.
Atopic dermatitis was more common among the Chinese (21.6%) and Malays (19.8%) compared with the Indians (16%) and other races (14%). The onset of the disease occurred before the age of 10 years in 49.5% of the 16 year olds. "Pure"
atopic dermatitis without concomitant respiratory
allergies was noted in 788 respondents (30.7%); 1775 (69.3%) suffered from a "mixed" type, with 34.3% having
allergic rhinitis, 9.5% having
asthma and 25.5% having both
asthma and
allergic rhinitis. More boys had
atopic dermatitis and concomitant respiratory
allergies whereas more girls were affected with "pure"
atopic dermatitis alone (1.4 : 1). At least one first-degree family member with atopy was noted in 1435 children (56%):
atopic dermatitis (70%),
asthma (62%) and
allergic rhinitis (68%). Among siblings with one parent with
atopic dermatitis, 37% had either a father or a mother with
atopic dermatitis. Common aggravating factors reported included exercise, heat and sweating, grass intolerance, thick clothing and stress.
Pityriasis alba was noted in 25% of the study population,
keratosis pilaris in 13% and
ichthyosis vulgaris in 8%. Most respondents had mild to moderate
atopic dermatitis that could be controlled with a fairly simple regimen of moisturizers, topical
steroids,
antihistamines and
antibiotics.
CONCLUSIONS: