Contact sensitivity in atopic dermatitis

$\text{Background:}$ There is some debate about whether the prevalence of contact allergy in patients with atopic dermatitis is the same as in the general population. $\text{Objective:}$ The aim of this study was to estimate the prevalence of allergic and irritant patch test reactions in patients with atopic dermatitis and to relate these to clinical patterns of disease. $\text{Methods:}$ One hundred twenty-two patients with atopic dermatitis were patch tested during a 3-year period. $\text{Results:}$ Sixty patients (49%) had one or more positive allergic reactions, and 49 patients (40%) had one or more irritant reactions. Positive allergic responses to topical preparations were found in 25 patients (21%) with six reacting to topical steroids. Overall, 54 (44%) had allergic reactions considered to be relevant to their clinical problem. Nickel sulfate, fragrance mix, lanolins, and neomycin were the most common allergens giving allergic reactions. $\text{Conclusion:}$ This study showed the importance of allergic and irritant factors in the causation of exacerbations of atopic dermatitis. Patch testing is helpful in the management of patients with worsening atopic dermatitis and should be undertaken at an early stage in patients whose disease is difficult to control.