Contact sensitivity in children and adults with atopic dermatitis--a chronological study

61 atopic dermatitis patients were subjected to a second patch testing 3-15 years (average 7.3 years) after the first contact sensitivity examination. The comparison between the results of the two studies revealed that 26.2% of patients had been sensitive to one or more haptens at the first patch testing and that 24.6% reacted positively at the second. 9 subjects (14.8%) still manifest contact sensitivity, while 6 (9.8%) reversed to positivity and 7 (11.5%) to negativity. The chemicals most frequently involved were nickel sulphate, potassium dichromate, benzoyl peroxide, diphenylguanidine. This study demonstrates that contact reactions are not linked to susceptibility to skin irritants in atopic dermatitis patients and that they tend to increase with time.