Prostaglandin synthetase inhibitors and food intolerance

12 patients with adverse reactions to foods are discussed, including 1 with biopsy-proven ulcerative proctitis. 10 had predominantly gastrointestinal symptoms (diarrhoea, abdominal pain, vomiting) and two had rhinitis and headache. Skin tests (in all but two) and radioallergosorbent tests (RAST) in some patients were negative. All of the patients were challenged in hospital with the offending food, either alone or preceded by a prostaglandin synthetase-inhibiting drug (aspirin, indomethacin or Ibuprofen). In 11 of the 12 patients this premedication prevented both the gastrointestinal and the more remote symptoms. Blood and stool prostaglandin measurements (PGE2 and PGF2 alpha) showed changes which correlated with clinical symptoms and did not occur if one of the inhibiting drugs had been given prior to challenge.