Ultraviolet therapy in lupus

Sunlight is a well-established factor in the induction and exacerbation of lupus erythematosus. Although experimental reproduction of lupus erythematosus lesions with wavelengths shorter than 320 nm was demonstrated previously, the effect of wavelengths longer than 320 nm was not investigated adequately. In this study we show that the action spectrum of lupus erythematosus reaches into the UVA region. A total of 128 patients with lupus erythematosus underwent phototesting with the use of polychromatic UVB and long-wave UVA. Subsets of the disease consisted of discoid lupus erythematosus (n = 86), subacute cutaneous lupus erythematosus (n = 22), and systemic lupus erythematosus (n = 20). Skin lesions clinically and histologically compatible with lupus erythematosus were induced in 64% of patients with subacute cutaneous lupus erythematosus, 42% of patients with discoid lupus erythematosus, and 25% of patients with systemic lupus erythematosus. The action spectrum of the induced lesions was within the UVB range in 33% of patients, in the UVA range in 14%, and in the UVB and UVA range in 53%. In positive test reactions patchy dark erythema and urticarial plaques developed within a few days. In some patients typical discoid lesions persisted for months.

We studied 72 patients with subacute cutaneous lupus erythematosus (SCLE). Forty-nine of the patients had been part of an earlier study. The cutaneous disease was primarily annular in 17 patients, papulosquamous in 48, and a combination in 7. Although the major feature of SCLE is nonscarring, non-atrophy-producing lesions, scarring discoid lesions were observed in 21 patients. Thirty-six patients fulfilled criteria for systemic lupus erythematosus. Cytoplasmic antibodies were present in only 22 patients. However, in the group of 23 patients recently analyzed, 13 of 22 tested had anti-Ro (SS-A) and/or anti-La (SS-B). HLA-DR3 was present in 22 of 59 patients. Neither anti-Ro (SS-A) nor HLA-DR3 correlated with any clinical finding. Forty-seven patients have had continued activity of their disease, but in most patients, the disease has been controlled with sunscreens, topical and intralesional corticosteroids, and oral hydroxychloroquine. A broad spectrum of systemic lupus erythematosus-associated phenomena can occur in patients with SCLE. The disease is frequently easily controlled, and may become quiescent. This subset of lupus patients is less distinctive than has been previously suggested.

Photosensitivity was assessed in 125 patients with systemic lupus erythematosus (SLE) and in 281 patients with rheumatoid arthritis (RA) as controls. Photosensitivity was reported by 87/119 (73%) patients with SLE and in 62/269 (23%) patients with RA; involving the face in 72/122 (59%) patients with SLE, then arms, chest, and neck. Patients with SLE reported that sun exposure could exacerbate various systemic symptoms, 51/121 (42%) reported medical treatment for photosensitivity and 41/118 (35%) reported that photosensitivity had a significant impact on their lifestyle. There was no significant difference in disease severity, as judged by physician or laboratory results, between patients scoring high or low on the photosensitivity scale.