A Study of the Use of Methotrexate in the Treatment of Chronic Idiopathic Urticaria

Multi-centre Prospective Randomised Double-blind Placebo-controlled Study of Methotrexate in the Treatment of Chronic Idiopathic Urticaria

The purpose of this study is to determine whether methotrexate produces significant improvement in chronic idiopathic urticaria, compared with placebo

Chronic idiopathic urticaria is thought to affect approximately 0.1% of the population. It can be very disabling and difficult to treat. Antihistamines are the only drugs licensed for treatment of urticaria, however there is a group of severely affected patients with chronic idiopathic urticaria who fail to respond. Previous trials have shown ciclosporin to be beneficial, and small studies support the use of intravenous immunoglobulins and plasmapheresis. However, not only are these options expensive, but since chronic idiopathic urticaria may persist for years, their prolonged use may be limited by adverse effects. We have previously published a report of 2 patients who responded to methotrexate, and wish to properly evaluate the efficacy of methotrexate in the treatment of CIU.

In the first part of the study patients will be given either placebo or methotrexate for 8 weeks and in the second part of the study, non-responders will be offered open labelled methotrexate for 8 weeks.

Inclusion Criteria:

• severe unremitting chronic idiopathic urticaria
• disease resistant to treatment with antihistamines
• aged 18 years or more

Exclusion Criteria:

• predominant physical urticaria
• urticarial vasculitis
• any contraindication to the use of methotrexate, eg. pregnancy / breast feeding, women wanting to conceive or man wanting to father a child within 12 months of entry, use of drugs which interact, underlying medical conditions
• use of immunosuppressant within 4 weeks of entry