Controlled therapeutic trials in polymorphic light eruption

Abstract

A series of controlled trials of treatments for polymorphic light eruption (PLE) with oral beta-carotene, ketoprofen and chloroquine, and topical benzimidazole sunscreen cream is described. Clinical features were recorded using diary cards filled out by the patients, and exposure to UVR was measured individually in all patients with film badges. Symptoms were found to be dependent on exposure. None of the treatments proved very effective, but beta-carotene seemed to give significant slight protection against irritation and erythema, though this was not confirmed in a repeat study using a higher dose. Chloroquine seemed to protect slightly against irritation. As the degree of improvement with chloroquine and beta carotene is quite small, equivalent to a protection factor of 2, it is arguable whether these treatments as used here are worthwhile and in the case of chloroquine, with its risk of adverse side effects, whether it is justifiable. Other treatment and dose regimes are possible and further trials seem worthwhile. Our studies have helped to define the special difficulties in collecting objective data in PLE and should improve the methods for assessing treatment in the photodermatoses.

Treatment of polymorphic light eruption

“…The severity of rash reduced by two points on the visual analogue scale ( P <0.01), but PLE was not abolished in most patients. An earlier study by Corbett et al (62) of 120 PLE patients taking chloroquine 400 mg daily for 12 weeks found only a modest reduction in skin irritation. In both studies, full autoantibody screening had not been available and it is possible that some cases of subacute lupus erythematosus, which is responsive to hydroxychloroquine, might have been misdiagnosed as PLE.…”

Influence of oral antioxidants on ultraviolet radiation‐induced skin damage in humans

“…Studies of the effects of β‐carotene on UVR‐induced inflammation in healthy humans have given conflicting results, some showing a reduction in erythema (37) and others no effect (38, 39). An open study of oral β‐carotene combined with canthaxanthin (a xanthophyll carotenoid) in 50 patients with polymorphic light eruption (PLE), suggested benefit (40), but controlled studies failed to confirm benefit of carotenoids in this photosensitivity condition (41, 42). A case–control study of 88 male patients found the incidence of NMSC was inversely related to serum β‐carotene levels (43), but cohort studies show no relationship between β‐carotene intake and development of basal cell carcinoma (BCC) (44, 45).…”

Polymorphous light eruption

“…Both have been shown to be somewhat effective in treating flares of PMLE and alleviating itch, but neither appear to offer much preventive benefit 8,17 , 37 . Similarly, oral antihistamines, antimalarials, and β‐carotene may provide some symptom relief, but have not been shown to be very effective 6–8,38 . Thalidomide has been used with some success, but the serious adverse side‐effects associated with this medication have limited its use 6 …”