Correspondence

Absence of Toxicity of Avenin in Patients with Dermatitis Herpetiformis

N Engl J Med 1999; 340:321January 28, 1999

Article

To the Editor:

Several studies have shown that oats are not toxic in patients with celiac disease and dermatitis herpetiformis.1-4 Avenin is a protein in oats and has similarities to wheat gliadin. Both are prolamins and are rich in glutamine and proline. It has been argued that in large quantities avenin may still be toxic in patients with celiac disease because of the similarity of the peptide sequences in avenin and gliadin. We therefore conducted an avenin-challenge study in two patients with dermatitis herpetiformis and gluten-sensitive enteropathy. The two patients had been following a gluten-free diet for 28 and 26 years, and in both, rash and enteropathy had been completely controlled by diet alone. Both had undergone a gluten challenge 15 years earlier, and both had subsequently had a recurrence of rash and enteropathy.5 In both patients the rash and enteropathy cleared once they resumed a gluten-free diet. Our study was approved by the institutional review board at St. Mary's Hospital. The patients provided written informed consent for the intestinal biopsies.

Avenin was extracted from pure oats (Peter Kölln, Elmshorn, Germany). The avenin challenge consisted of the ingestion of 2.5 g of avenin (equivalent to 300 g of oats, or about 10 bowls of oatmeal) daily for five days and then a further 2.5 g nine days later. Biopsy specimens of the small intestine were obtained 24 hours before the challenge and again 24 hours and five days after the start of the challenge. Skin-biopsy specimens were obtained before the challenge and 16 days later. Blood was obtained before the challenge and 16 days later for the measurement of antiendomysial, antireticulin, and IgA antigliadin antibodies.

Examination of the intestinal-biopsy specimens showed that avenin did not change the ratio of the villous height to the crypt depth, the height of enterocytes, or intraepithelial-lymphocyte counts (Table 1Table 1Results of Duodenal Histologic Analysis and Intraepithelial-Lymphocyte Counts before and after Avenin Challenge.). IgA was absent in the skin-biopsy samples before and after the avenin challenge. No circulating antiendomysial, antireticulin, or IgA antigliadin antibodies were detected before or after the challenge.

We found that oat avenin had no toxic effects in two patients with dermatitis herpetiformis who were sensitive to gluten. Our results imply that the peptides that are toxic in celiac disease are not present in avenin and that patients with celiac disease and dermatitis herpetiformis can tolerate oats in their diet, even in large quantities. However, the latter is true only if the oats are pure — that is, uncontaminated by wheat, rye, or barley.

Catherine Hardman, M.R.C.P.
Lionel Fry, F.R.C.P.
St. Mary's Hospital, London W2 1NY, United Kingdom

Arthur Tatham, Ph.D.
University of Bristol, Bristol BS18 9AF, United Kingdom

Huw J.W. Thomas, F.R.C.P.
St. Mary's Hospital, London W2 1NY, United Kingdom

5 References

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Citing Articles (2)

Citing Articles

1. 1

   Diana Bolotin, Vesna Petronic-Rosic. (2011) Dermatitis herpetiformis. Journal of the American Academy of Dermatology 64:6, 1027-1033
   CrossRef

2. 2

   Flavia Fedeles, Michael Murphy, Marti J. Rothe, Jane M. Grant-Kels. (2010) Nutrition and bullous skin diseases. Clinics in Dermatology 28:6, 627-643
   CrossRef