Nordic Occupational Skin Questionnaire (NOSQ-2002): a new tool for surveying occupational skin diseases and exposure

In order to qualify as a case of atopic dermatitis, we propose that an individual must have an itchy skin condition plus three or more of the following: history of flexural involvement, a history of asthma/hay fever, a history of a generalized dry skin, onset of rash under the age of 2 years, or visible flexural dermatitis. When tested in an independent sample of 200 consecutive dermatology outpatients of all ages, this arrangement of the diagnostic criteria achieved 69% sensitivity and 96% specificity when validated against physician's diagnosis. Based on the findings of this first exercise, minor modifications in the wording of the criteria were undertaken, and these were tested on a sample of 114 consecutive children attending out-patient paediatric dermatology clinics. Overall discrimination improved, with a sensitivity of 85% and specificity of 96%. The simplified criteria are easy to use, take under 2 min per patient to ascertain, and do not require subjects to undress. These two independent validation studies suggest that the newly proposed criteria for atopic dermatitis perform reasonably well in hospital out-patient patients. Further validation in community settings and in developing countries is needed.

The level of agreement between 14 physicians as to what constitutes a case of atopic dermatitis was tested on 15 selected patients with a range of diagnoses. Between-observer agreement was good, with a mean pair agreement index (P0) of 0.94, and a chance corrected index (kappa) of 0.78. Between-observer agreement in the recording of 18 separate physical signs of atopic dermatitis was then tested by asking the 14 physicians to note the presence or absence of each sign in a different group of patients to those seen in the first part of the exercise. Substantial between-observer agreement (kappa > 0.61) was only present for truncal dermatitis. Most signs showed only fair to moderate agreement (kappa 0.21-0.60), and some signs, such as keratosis pilaris, xerosis, orbital pigmentation, fine hair, and extensor dermatitis, showed poor agreement (kappa 0.01-0.20). The findings were similar when the responses of two independent observers from the national study outlined in Paper I were compared for each sign. Within-observer variation for the recording of physical signs was substantially better than between-observer variation. Physicians interested in atopic dermatitis agree reasonably well on what constitutes a typical case of atopic dermatitis. Between-observer variation with regard to some physical signs of atopic dermatitis is of a magnitude which argues against their continued use in clinical and epidemiological studies.