The natural history of atopic dermatitis and its association with Atopic March.

BACKGROUND: Atopic dermatitis (AD) is the first manifestation of Atopic March. The natural history of AD and predictive factors for Atopic March have not been widely studied in Asia.

OBJECTIVE: To study the natural history and associated factors of disease remission and risk of respiratory allergy in Thai children with AD.

METHOD: Medical records of AD patients attending Allergy clinic at Siriraj hospital from 2004-2014 were reviewed. Patients were further followed-up to obtain current symptoms and treatment.

RESULTS: One hundred and two AD patients (60.8% female) were followed for 10.2±4.7 years. The median age at diagnosis was 1.5 (0.1-12.0) years. The most common allergen sensitization was Dermatophagoides pteronyssinus and Dermatophagoides farinae. Forty-four percent of patients had complete remission at the median age of 6.3 (2.0-15.0) years. Forty-seven percent of early AD patients (onset <2 years) had concomitant food allergy which egg and cow's milk were leading causes. The remission rate of AD was higher in early AD than later onset AD (p=0.02). Allergic rhinitis (AR) and asthma were diagnosed in 61.8% and 29.4% of the patients at the median age of 4.6 and 3.8 years, respectively. Early AD and food allergies were significantly associated with early asthma (onset <3years) (OR=10.80, p<0.01 and OR=8.70, p=0.01).

CONCLUSIONS: Almost half of AD children had complete remission at school age with a better prognosis in early AD. At preschool age, two-thirds and one-third developed AR and asthma, respectively. Early AD and food allergy were risk factors of early asthma.