Author Affiliations: Department of Pediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China (Hon KL, Wang SS, Wong WL,  Poon WK, Mak KY, Leung TF)

Corresponding Author: Dr. Kam-lun Ellis Hon, Department of Pediatrics, The Chinese University of Hong Kong, 6/F, Clinical Science Building, Prince of Wales Hospital, Shatin, Hong Kong, China (Tel: 852 2632 2859; Fax: 852 2636 0020; Email: ehon@hotmail.com/ehon@cuhk.edu.hk)

Background: Atopic eczema is a common and distressing disease. This study aimed to review the age-dependent pattern of atopic sensitization to food and aeroallergens in patients with eczema by skin prick testing.

Methods: The results of skin prick test (SPT), serum IgE, bronchial challenge test, and family history of atopy in eczema patients seen at a pediatric dermatology clinic were reviewed.

Results: SPT results were available in 816 eczema patients. In these patients, 90% had atopic sensitization to at least one aeroallergen, 69% to at least one food allergen, and 94% to at least one allergen by SPT. Together with a family history of atopy in parents or siblings and a personal history of airway atopies, 97% and 99.8% of the patients were atopic, respectively. Bronchial hyper-reactivity (BHR) was demonstrated in 44% of 339 patients. Aeroallergen was more prevalent than food allergen sensitization among children older than 10 years. The mites (D. pteronysissnus, D. farinae and Blomia Tropicalis) were the most prevalent allergens regardless of age and BHR, but D. pteronysissnus and D. farinae sensitization were more prevalent among BHR-positive patients. Beef is the least sensitized food protein in all ages.

Conclusions: The majority of patients with eczema are atopic to aeroallergens. The mites (D. pteronysissnus, D. farinae and Blomia Tropicalis) are the most prevalent allergens regardless of age and BHR.

Key words: aeroallergens; atopic dermatitis; eczema; food allergens; IgE; skin prick test