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July 21, 2008

UV-A1 Phototherapy for Sclerotic Skin Diseases: Implications for Optimizing Patient Selection and Management

Arch Dermatol. 2008;144(7):912-916. doi:10.1001/archderm.144.7.912

Phototherapy is among our most powerful weapons for fighting against chronic inflammatory skin diseases. Since the middle of the past century, numerous controlled studies of broadband UV-B, narrowband UV-B, and psoralen plus UV-A have demonstrated that phototherapy is highly effective in treating cutaneous diseases, such as psoriasis and atopic dermatitis. In 1981, the development of a new lamp that emits radiation predominantly between 340 and 400 nm was described, introducing the era of UV-A1 phototherapy.1 Three different dosage regimens of UV-A1 are distinguished: high-, medium-, and low-dose UV-A1, emitting 90 to 130, 30 to 89, and less than 30 J/cm2, respectively. In contrast to UV-B, which penetrates into the papillary dermis only, longer wavelengths in the UV-A region can reach the subcutis as well. In 1992, UV-A1 was first introduced as a highly potent treatment option for acute atopic dermatitis.2 Three years later, a letter reported that UV-A1 was capable of reducing skin sclerosis in patients with localized scleroderma (LS).3 Since then, a variety of case reports and uncontrolled open studies have been published on UV-A1 phototherapy for sclerotic skin diseases.