The use of folic acid supplementation in psoriasis patients receiving methotrexate: a survey in the United Kingdom.

There is little literature on the use of folic acid supplementation in psoriasis patients being treated with methotrexate. Under the auspices of the British Association of Dermatologists we surveyed, using a questionnaire, the use of folic acid supplementation with methotrexate therapy for psoriasis by dermatologists in the UK. Six-hundred and fifteen questionnaires were sent and 153 responses were received (25%). One-hundred and fourteen of the responders (75%) used folic acid supplementation with methotrexate in psoriasis patients. Thirty (26%) of these used folic acid supplementation in all patients taking methotrexate and 84 (74%) used folic acid only under certain circumstances, the most common of which was an elevated erythrocyte mean corpuscular volume. Forty-six per cent of respondents believed that folic acid supplementation reduced nausea and 60% believed that folic acid did not interfere with the efficacy of methotrexate. A wide variety of dosing regimens were used for folic acid supplementation. In the absence of guidelines and controlled trials, there is great variation in the indication for use, dosing regimens used and beliefs regarding methotrexate supplementation for psoriasis. Randomized controlled trials are necessary to address these questions.