Fumaric acid esters in the treatment of psoriasis - commentary on ‘Treatment of severe, recalcitrant, chronic plaque psoriasis with fumaric acid esters: a prospective study’ by Wain et al.

ORIGINAL ARTICLE, p427 The study by Wain et al.1 on use of fumaric acid esters (FAE) in psoriasis is timely, as this treatment is increasingly prescribed by U.K. dermatologists for moderate to severe psoriasis. An unlicensed and expensive drug, it has yet to be exposed to head‐to‐head randomized clinical trials with licensed drugs such as acitretin, methotrexate and ciclosporin. FAE is licensed for the treatment of psoriasis in Germany, where most of the clinical studies and experience with this drug have originated.2 The risk of organ toxicity with FAE is less than for ciclosporin and methotrexate, yet efficacy appears to be similar to these licensed drugs.3 Importantly, Wain et al. highlight that some patients respond to FAE having previously failed to respond to ciclosporin or methotrexate. However, Wain et al. also highlight that the side‐effect profile limits acceptability of FAE in some patients; gastrointestinal upset and intermittent, but severe flushing are the main problems. Weekly small dosage increments allow patients to accommodate gradually to FAE; first signs of efficacy occur after 4–6 weeks of treatment.3 Those who respond well with clearance of psoriasis tend to make light of the gastrointestinal upset and flushing.3 However, about 30–40% experience these side‐effects to an unacceptable degree before efficacy has occurred and discontinue treatment.3 For those who respond, maintenance treatment is used; in many patients the dose of FAE can be gradually decreased without loss of efficacy. Blood monitoring at 2‐monthly intervals is less frequent than for ciclosporin and methotrexate, reflecting the better toxicity profile for this immunosuppressive drug.3 Although the cost of this drug is high, it is much lower than the cost of biological therapies.4