High Quality Content by WIKIPEDIA articles! Enzyme potentiated desensitization, or EPD, is a treatment for allergies developed in the 1960s by Dr. Len McEwen in the United Kingdom. EPD uses much lower doses of antigens than conventional treatment, with the addition of an enzyme, beta glucuronidase. EPD is available in the United Kingdom and Canada for the treatment of hay fever, food allergy and intolerance and environmental allergies.