Lichen ruber planus in occupational groups in total populations.

Distributed on 66 occupational groups (and 170 individual occupations) the prevalence of lichen ruber planus within the groups was determined by examining nearly every person in the total populations of 39,418 persons in five different areas in Sweden. The prevalence of l.r.p. in the total population was 0.3 per cent for males and 0.1 per cent for females. When l.r.p. prevalences were compared between different occupational groups, disturbing influences from age differences between the groups were eliminated by the standard population method. The indices calculated by aid of computer were used for direct ranking of the occupational groups from those with the highest to those with the lowest prevalences. In 33 of the 66 occupational groups (and in 129 of 170 individual occupations) no l.r.p. was found. In 24 male and 6 female occupational groups an overaverage high prevalence of l.r.p. was found. In two occupational branches, i.e. agriculture and forestry work (male agricultural workers, farmers, gardeners, garden workers and forest workers) and engineering and building metal work (steel-workers, plate-workers, machine and engine repairers, machine and engine mechanics, engineering workers, plumbers, metal workers) an overaverage high prevalence of l.r.p. was found in nearly all occupational groups. The results indicate that l.r.p. is more prevalent in occupational groups, in which the work dirties the skin (with i.e. soil, oil, cement dust), while in occupational groups with "clean work" the disease was less prevalent. However, there were exceptions. 67.7% of the males, 55.5% of the females had their debute lesions on the lower legs; in 21% of the males and 22.2% of the females the l.r.p. lesions debuted on the wrists. These are areas liable to exposure for different chemical substances and trauma.