Clinical examinations to validate self-completion questionnaires: dermatitis in the UK printing industry

A self-completion questionnaire sent to 2600 Nottinghamshire members of the Graphical Paper and Media Union elicited a 62% response. Forty one per cent of respondents reported suffering a skin complaint at some time and 11% had a current skin problem on the hand. This paper reports the validation stage of the study. Samples of 45 'cases' of self-reported dermatitis and 60 'controls', who reported they had never suffered a skin complaint, were clinically examined. All 45 self-reported cases were clinically confirmed as dermatitis. Occupationally related irritant contact dermatitis (ICD) was diagnosed in 20 (44%); 26 (58%) complaints were thought to be induced or exacerbated by occupation. Of the controls, 21 (35%) were also diagnosed with a skin complaint, the majority being mild, with an occupational association in 17, the majority (15) being ICD. Sixteen ICD cases were patch tested resulting in positive reactions to colophony, neomycin, nickel and potassium dichromate (2 of each). Two cases of basal cell carcinoma on the face were also identified, of which the participants were unaware. Although there was no false positive self-reporting there was a considerable number of false negatives, demonstrating the importance of clinical validation of questionnaires relating to industrial skin disease. This study has highlighted the need for improvement in skin care provision in the printing industry.