Contribution of Patch Tests with Occupational Handled Products in the Diagnosis of Occupational Contact Dermatitis: A 10-year Review

Abstract

Introduction. Allergic contact dermatitis (ACD) is a common occupational disease. Its diagnosis is essentially based on interrogation and patch tests. However, commercially available batteries are sometimes not appropriate for the working conditions and the handled products, which must then be tested. In Tunisia, no previous study has focused on the contribution of patch tests with handled products in the workplace. The objective of this study is to establish the sociodemographic and occupational profile of the patients benefiting from patch tests with handled products in the workplace to identify the characteristics of these products as well as to evaluate the relevance of their positivity and their contributions in terms of aetiological diagnosis of occupational ACD. Methods. This is a retrospective descriptive epidemiological study conducted for a period of 10 years from January 1st, 2006, to December 31, 2015, among patients exercising a professional activity and consulting the Dermato-Allergology Unit of the Occupational Medicine ward of the University Hospital Farhat Hached of Sousse for the exploration of ACD. Results. During the study period, 113 patients received patch tests of handled products in the workplace with a prevalence of 7.3% of patch-tested patients during the same period. The mean age was 35.79 ± 9.45 years with a male predominance (sex ratio = 1.35). The most represented activity sectors were the health sector in 30.1% and the textile sector in 21.2%. The majority of patients were professionally active (61.9% of the study population) with an average professional seniority of 10.28 ± 8.49 months. In total, 138 patch tests with handled products were carried out of which 46 tests were positive (33.3%). After the analytical study, variables independently significantly associated with the positivity of patch tests with handled products in the workplace were the male gender and the working in the plastics industry. An occupational disease was declared to the National Health Insurance Fund for 8 patients, i.e., 7.1% of cases. Conclusion. Patch tests with handled products in the workplace can provide strong arguments for the professional origin of the ACD.

Contact allergens in African countries: A review of published patch test studies

“…Nickel, cobalt, potassium dichromate, fragrance mix and PTBP were common allergens that gave a positive reaction in the majority of the studies. Figure 1B shows the frequencies of patch tested patients from the first group with a positive reaction for each of the five dominating allergens in Lagos [12][13][14] and Abuja, 15 Nigeria, Addis Ababa 16,17 and Mekele, 18 Ethiopia and Sousse, 19 Tunisia, respectively. Put together, nickel, cobalt, potassium dichromate, fragrance mix and PTBP were identified as contact allergens in approximately 40%-90% of the patch tested individuals in Africa not selected for specific skin sites except from the eldest study from Nigeria from 1985.…”

New causes of occupational allergic contact dermatitis

“…This means not only testing with a screening series, but also industry or job specific allergens and possibly custom testing with the worker's own workplace materials. Alouli et al [60] examined testing with workplace products done between 2006 and 2015. One hundred and thirty-eight patch tests were done with workplace materials of which 46 (33.3%) were positive.…”