Narrow-band UVB phototherapy and psoralen–ultraviolet A photochemotherapy in the treatment of cutaneous mastocytosis: a study in 20 patients

Background: In mastocytosis, the skin is almost invariably involved, and cutaneous symptoms deeply affect patients' quality of life. Methods: A retrospective observational analysis of patients affected by cutaneous mastocytosis (CM) and indolent systemic mastocytosis (ISM) treated with phototherapy/photochemotherapy (PUVA or NB-UVB) has been conducted. For each patient, total numbers of PUVA or NB-UVB exposures, the cumulative UV dose (J/cm2), serum tryptase profile, and pruritus, before and after treatment, according to the visual analogue scale (VAS) were considered. Skin lesions of each patient were assessed, before and after treatment, according to a cutaneous scale score. Results: Twenty patients affected by CM and ISM were studied; in particular, 10 patients received NB-UVB therapy, and other 10 patients received PUVA. A statistically significant mean reduction of pruritus in both groups (P < 0.01) was observed. The number of treatments necessary to obtain symptom relief was significantly lower in the PUVA group, but the mean exposure dose was significantly higher, if compared to the NB-UVB group. Serum tryptase levels showed a downward trend. The cutaneous score improved in both groups. Limitations: This study was a retrospective study with a small sample size and without a control group. Conclusion: This work provides evidence that both NB-UVB and PUVA represent a safe and useful second-line therapy of the cutaneous symptoms in mastocytosis.