Medium-dose is more effective than low-dose ultraviolet A1 phototherapy for localized scleroderma as shown by 20-MHz ultrasound assessment

Background

Recent studies suggest that ultraviolet (UV) A1 phototherapy is an effective treatment for localized scleroderma (LS); however, the optimum UVA1 dose remains to be determined.

Objective

We sought to compare the immediate and long-term efficacy of low- versus medium-dose UVA1 phototherapy for plaque-type LS.

Methods

Three comparable plaques in 16 patients were treated with 20 J/cm² UVA1, 70 J/cm² UVA1, or no irradiation. In total, 30 treatments were given. Skin thickness was determined by high-frequency ultrasound examination and clinical scoring. Assessments were done at baseline, immediately after treatment, and 3, 6, and 12 months thereafter.

Results

Ultrasound measurement showed a significantly greater reduction of skin thickness with 70 J/cm² than with 20 J/cm² at all time points of the study except immediately after UVA1 treatment. The clinical score of the irradiated plaques also decreased substantially but failed to detect a significant difference between the two dose regimens.

Limitations

Our results only pertain to plaque-type LS and are limited by a small sample size.

Conclusion

Medium-dose provides for better long-term results than low-dose UVA1 in LS as shown by ultrasound assessment. With clinical scoring, no significant difference between the two UVA1 dose regimens was detected, indicating that ultrasound measurement is a more sensitive method for quantifying treatment-induced skin changes in patients with LS.

Key words: comparison of low- and medium-dose UVA1, high-frequency ultrasound, long-term follow-up, LS, UVA1 phototherapy