Medium-dose UVA1 cold-light phototherapy in the treatment of severe atopic dermatitis

Recently, conventional high-dose UVA1 phototherapy (340-400 nm) has been shown to be more effective than combined UVA-UVB therapy in the treatment of severe atopic dermatitis (AD). However, there are limitations of this treatment, such as intense sweating caused by the immense heat load during therapy and the high cumulative UVA1 doses that are required. For this reason, lavish UVA1 equipment was developed containing an advanced filtering and cooling system resulting in almost complete absence of heat load and sweating during therapy.

In this study we compared the monotherapeutic efficacy of conventional medium-dose UVA1, medium-dose UVA1 cold-light, and combined UVA-UVB phototherapy in the treatment of severe AD.

The study involved 120 patients with severe AD. Fifty patients each received conventional UVA1 or UVA1 cold-light phototherapy (15 days, 50 J/cm(2)/day), and 20 patients were treated with combined UVA-UVB (15 days, minimal erythema dose dependent). Severity of AD was scored by means of the SCORAD score, and clinical improvement was additionally monitored by serologic cytokine markers.

Six (12%) of 50 patients treated with UVA1, 2 (4%) of 50 patients treated with UVA1 cold-light therapy, and 4 (20%) of 20 patients treated with combined UVA-UVB therapy discontinued treatment prematurely because of an unsatisfactory clinical outcome or adverse reactions. Skin status improved or even cleared completely in 77.3% of the patients treated for 3 weeks with conventional UVA1 therapy and in 85.4% of the patients treated for 3 weeks with UVA1 cold-light therapy, resulting in a significant decrease in the SCORAD score in both UVA1 groups (P <.05 each). In the group treated with combined UVA-UVB, the SCORAD score also decreased but significantly less than in both groups treated with UVA1 photo-therapy (P <.05 each). At follow-up after 4 weeks, the patients treated with UVA1 displayed a more prolonged therapeutic benefit than the patients treated with UVA-UVB therapy. Plasma levels of soluble interleukin 2 receptors and soluble interleukin 4 receptors significantly decreased under both UVA1 and UVA1 cold-light phototherapy but not under combined UVA-UVB phototherapy.

Our study demonstrates that medium-dose UVA1 cold-light phototherapy displays advantages compared with conventional UVA1 phototherapy caused by the almost complete absence of heat load and intense sweating and is more effective than UVA-UVB phototherapy in the treatment of severe AD.