Gut 55:1662-1663 doi:10.1136/gut.2006.104943
  • Letter

An exuberant inflammatory response to E coli: implications for the pathogenesis of ulcerative colitis and pyoderma gangrenosum

  1. D J B Marks1,
  2. F Z Rahman1,
  3. M Novelli2,
  4. R C Yu3,
  5. S McCartney4,
  6. S Bloom4,
  7. A W Segal5
  1. 1Department of Medicine, University College London, London, UK
  2. 2Department of Histopathology, University College Hospital, London, UK
  3. 3Department of Dermatology, University College Hospital, London, UK
  4. 4Department of Gastroenterology, University College Hospital, London, UK
  5. 5Department of Medicine, University College London, London, UK
  1. Correspondence to:
    Professor A W Segal
    Department of Medicine, University College London, London WC1E 6JJ, UK; t.segal{at}

    A recent study investigated acute inflammatory responses in patients with inflammatory bowel disease.1 Subjects received 1 mg of heat killed Escherichia coli subcutaneously into each forearm. The magnitude of the ensuing local inflammatory responses, measured as increases in local blood flow, peaked in healthy individuals by 24 hours and resolved within 48 hours. In contrast, the response in two patients with ulcerative colitis was abnormally protracted (supplementary fig 1; supplementary fig 1 can be viewed on the Gut website at

    Figure 1

     Macroscopic and microscopic appearances of the skin lesions. (A) A prolonged erythematous reaction developed at each injection site in this patient. These subsequently (B) blistered and (C) ulcerated. (D) Ulcers completely re-epithelialised after sequential treatment with infliximab, clobetasol, and topical tacrolimus. (E) Biopsies taken from the margin of the lesion showed granulation tissue, active inflammation in the subcutis, fibrin exudation into the superficial dermis, and pseudoepithelialomatous hyperplasia. High power images (inset) revealed a predominantly neutrophilic leucocyte infiltrate. …