Provoking factors, including chemicals, in Dutch patients with vitiligo

Summary Background  In vitiligo, many provoking factors have been described, but epidemiological data, especially on the role of contact with chemicals, are scarce. Objective  To obtain an insight into the patient-reported factors provoking vitiligo, including contact with chemicals. Methods  A retrospective cohort study was conducted on all 1264 patients with vitiligo who visited the Netherlands Institute for Pigment disorders from January 2003 to December 2007. Patients for whom an exogenous provoking factor was recorded were sent a questionnaire. Subsequently, patients who mentioned a chemical provoking factor were contacted to elucidate the alleged causal relationship between exposure to the chemical and the onset of vitiligo. Results  A total of 300 out of the 1264 patients indicated that provoking factors had played a role in their disease. Two hundred and forty-six patients were sent a questionnaire, which was returned by 177 (response rate of 72%). Emotional stress was indicated as a provoking factor in 98 patients (55·4%), 51 patients (28·8%) recorded sunburn, 34 patients (19·2%) recorded mechanical factors and 20 patients (11·3%) other factors. Of 29 patients (16·4%) who indicated a chemical factor, a presumed causal relationship could be corroborated in four. The chemicals involved were para-tertiary butylphenol (n = 2), captan (n = 1) and diphencyprone (n = 1). Conclusion  The majority of the patients with vitiligo from this study did not mention provoking factors, but the ones who did point to emotional stress in more than half of the cases. Of the 29 patients who assigned chemical provoking factors, solvents were mainly indicated. However, a presumed relationship with the chemical could be corroborated in only four patients.