Photodynamic Therapy for Granuloma Annulare: More than a Shot in the Dark

Granuloma annulare (GA) is a benign granulomatous and inflammatory
skin disorder. The pathogenesis remains enigmatic and convincingly
effective treatment options are not available. Inspired by a report
showing photodynamic therapy (PDT) to be effective in a single
patient with GA, we sought to evaluate this benefit in a series of
patients with GA. Observations: PDT was performed in 7 consecutive
patients with histologically confirmed GA located at the
extremities. First, 20% ALA gel was applied under an occlusive
dressing for 5 h, followed by illumination with 100 J/cm(2) by a
standard red-light source. In total, 2-3 PDT sessions were
performed, with an interval of 2-4 weeks between each session.
Treatment was stopped when complete remission was achieved or when
GA lesions remained unchanged after 2 consecutive PDT sessions. The
overall response rate was 57%. In 2 patients (29%), GA cleared
completely, in 2 patients ( 29%) the skin lesions improved markedly
and in 3 patients (43%) no clinical response could be observed.
Conclusion: These promising results should be evaluated in larger
controlled studies. In selected patients, PDT might be a valuable
recruit for the sparse armory available to treat GA. Copyright (c)
2008 S. Karger AG, Basel