Allergic Contact Dermatitis and Patch Test Responses in Atopics

Abstract

Introduction: The frequency of atopic dermatitis (AD) in patients with allergic contact dermatitis (ACD)
varies between 13-68%. There are certain similarities in the clinical presentations of patients with atopic
dermatitis and allergic contact dermatitis.
Objectives: This study aimed to determine frequency of atopic dermatitis among patients with allergic
contact dermatitis at the skin clinic of the Lagos University Teaching Hospital (LUTH) between September
2003 and October 2004. It will also highlight the difference in patch test responses in the atopics and the
non atopics.
Methods: All consecutive patients with features of allergic contact dermatitis were examined for features
of atopic dermatitis using refined Hannifin and Rajka criteria (1980) and patch tested. Clinical features of
ACD in the patients with atopy were documented using a self-administered protocol. The patch test
responses in atopics and non atopics were compared using the chi square test and the odds ratio (OR).
Results: Thirty six (35.3%) of the 102 patients who presented with features of allergic contact dermatitis
during the study period were found to be atopics. There was a female preponderance of atopics with
allergic contact dermatitis (male to female ratio 1:2.3). Twenty four (66.7%) of the atopic patients patch
tested had features of chronic dermatitis. Nickel sulphate, potassium dichromate, cobalt chloride and
fragrance mix were the most common allergens found in the atopics in descending order.
Conclusion: There was no statistically significant difference in the patch test responses between the
atopics and the non atopics.