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Allergic Contact Dermatitis in Atopic Individuals
Exposure to topical treatment for atopic dermatitis (AD) may result in contact allergy, and clinicians should consider patch testing in AD individuals who report worsening or their skin despite continued treatment, a new study found. Results of 46,250 patients patch tested in a single center over 30 years were reviewed, comparing those with AD with those without AD. Among the findings:
- 9 allergens showed statistically significant difference between the 2 groups.
- Contact allergy to nickel, cobalt, and primin were less likely to arise in those with AD.
- Substances found in topical dermatological products were more likely to be associated with AD.
Citation:
Teo Y, et al. Allergic contact dermatitis in atopic individuals: Results of a 30-year retrospective study. [Published online ahead of print July 25, 2019]. Contact Dermatitis. doi: 10.1111/cod.13363.
In years past (20-30 years ago or more), most dermatologists were of the opinion that those with AD were less likely to develop allergic contact dermatitis (ACD). This was based primarily on the concept of differing immunologic mechanisms for the two conditions. Unfortunately, at the time, those with AD were not patch tested as commonly as they are now. A variety of recent studies have suggested that those with AD have just as much chance of becoming sensitized by contact allergens, as those without atopy. This report of the largest number of patients with AD who have been patch tested shows almost no overall difference in frequency of positive patch tests, compared to patients without AD. There is a small decrease in metal allergy and a small increase in allergy to topical medication ingredients in those with AD. Presumably the latter is due to greater use of topical emollients and medications in the AD group. Patients with AD that do not respond appropriately to treatment should be considered for patch testing to rule out concomitant ACD. — Joseph Fowler, Jr., MD, Clinical Professor of Dermatology, University of Louisville, KY