LAUSR

ceased (Fig. S1). He experienced a recurrence of two small patches on the posterior right thigh 6 months later, and these were treated with intralesional steroids with good response. Numerous treatment modalities for GA have been described in the literature; however, there have been only limited reports regarding the efficacy of pentoxifylline in GA (Table 1). Our three cases of generalised, perforating and localised GA showed some response after 1 month of treatment with pentoxifylline and continued improvement after 3 months of treatment. In the first case, a dose– response pattern was evident with small recurrences occurring on a lower dose and then clearing when pentoxifylline was increased. The improvement in all cases was striking suggesting that spontaneous regression would be an unlikely explanation. Pentoxifylline is a methylxanthine derivative that has been used in the treatment of various dermatological conditions. It has anti-inflammatory effects including modulation of immune cell activity and inhibition of proinflammatory cytokines such as TNF-a which is known to induce granulomatous inflammation. Pentoxifylline also decreases blood viscosity and improves tissue oxygenation. It has been hypothesised that GA pathogenesis potentially involves an immune-mediated vasculitis. The exact mechanism of action of pentoxifylline in GA is not known and may relate to a combination of immune modulation and TNF-a blocking action. Pentoxifylline is generally safe and well tolerated; side effects are predominantly dose related with the most common being nausea and vomiting (1–10%). Particular caution should be taken in patients with pre-existing coagulopathy or renal impairment, and patients should also be monitored for bleeding. With a good safety profile compared to systemic immunosuppressive therapies, pentoxifylline is worth considering in GA. Some patients may achieve long-term remissions but others may recur after weaning or cessation of therapy, in which case a maintenance dose could be considered to maintain clearance.