Severity of polymorphic light eruption in pre- and post-menopausal women: a comparative study

BackgroundPolymorphic light eruption (PLE) is approximately four times more common in women than in men and often begins in young adult life. It is hypothesized that patients with PLE have an inherent resistance to UVL-induced immunosuppression, which is a physiological phenomenon in normal healthy individuals. Consequently, in PLE there is a delayed-type hypersensitivity reaction to a UVL-modified skin antigen, which results in an inflammatory reaction and a variable rash. The female hormone, 17-oestradiol, has been shown to inhibit UVL-induced physiological suppression of contact hypersensitivity responses. This has been postulated to account for the female preponderance of PLE. If 17-oestradiol plays a significant part in the disease, one might hypothesize that the severity of PLE might reduce in women after menopause. ObjectivesTo compare the severity of PLE in pre-menopausal women with that in post-menopausal women. MethodsEighteen pre-menopausal and 18 post-menopausal women with PLE had their Polymorphic Light Eruption Severity Index (PLESI) scored by a single investigator. ResultsPre-menopausal women (mean age 40years; range 25-50) had a mean PLESI of 54.8 (range 0-86, SD 20.2). Post-menopausal women (mean age 63years; range 53-78) had a mean PLESI of 36.8 (range 0-74, SD 18.2). A significant difference in mean PLESI values between pre- and post-menopausal women was noted (18.0; 95% CI 4.9-31.0; P = 0.008). At the time of the study, three subjects in the pre-menopausal group and one subject in the post-menopausal group were on oestrogen preparations. Even after excluding the four patients on oral oestrogens, there remained a statistically significant difference in the mean PLESI scores between the pre-menopausal and post-menopausal groups (55.10 vs. 36.64; difference of 18.46, 95% CI: 4.0-32.91; P = 0.014). ConclusionsThe severity of PLE was significantly less in post-menopausal women as compared with pre-menopausal women.