Background/purpose: Disseminated granuloma annulare is a benign granulomatous skin disease of unknown etiology. Recently, UVA1 (340-400 nm) phototherapy has been found effective in a small series of four patients. The purpose of this two-center study was to determine the rate and duration of clinical response to UVA1 phototherapy in a larger cohort of 20 patients with disseminated granuloma annulare.
Methods: Twenty patients with long-standing, stable disease (median 42 months, 95% CI 23-105) underwent UVA1 phototherapy. Sixteen patients were treated with a high-dose regimen (median single dose 110 J/cm2, 95% CI 103-121) and four patients with a medium-dose regimen (median single dose 50 J/cm2, CI 50-50). The clinical response was graded on a 5-point scale [0 = none, 1 = poor, 2 = moderate, 3 = substantial, 4 = (near) complete]. After cessation of therapy, patients with a clinical score of 3 or 4 were followed up to evaluate the duration of clinical improvement.
Results: At the end of treatment, five patients each had substantial improvement or (near) complete clearance. Another five patients had a moderate response, three patients were considered as poor responders and two patients as treatment failures. Out of the 10 patients with good or excellent response nine were available for follow up. Of these, two patients were still clear after 3 and 6 months, and seven patients relapsed after a median of 3 months (95% CI 1.68-6.46).
Conclusions: UVA1 phototherapy provided good or excellent results in half of our 20 patients with disseminated granuloma annulare. In the majority of patients with a satisfactory response, however, discontinuation of treatment was followed by early recurrence of disease.