Asking people about a history of psoriasis may be useful for assessing psoriasis prevalence, but a similar questionnaire assessing atopic dermatitis does not appear to be as reliable of a method, according to a study published online July 7 in JAMA Dermatology.

Lea K. Nymand, from the University of Copenhagen in Denmark, and colleagues examined the test-retest accuracy of questionnaires for measuring psoriasis and atopic dermatitis prevalence among Danish adults. The analysis included 2,333 adults surveyed for psoriasis and 2,312 surveyed for atopic dermatitis at two different time points from May 15, 2018, to Nov. 20, 2020.

The researchers found that among participants reporting a history of psoriasis, agreement between individual responses was high (κ = 0.7558); however, among those reporting a history of atopic dermatitis, agreement was low (κ = 0.4395). The prevalence of reported psoriasis changed from 7.8 to 8.0 percent, while the prevalence of reported atopic dermatitis changed from 8.2 to 7.6 percent. Among those reporting dermatologist-diagnosed atopic dermatitis in 2018, more than one-third (36.9 percent) claimed in 2020 that they had never had atopic dermatitis.

"This inconsistency suggests that questionnaires on a history of atopic dermatitis will confer considerable risk of bias and misclassification," the authors write.

Two authors disclosed financial ties to the pharmaceutical industry.

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