Dermatitis Herpetiformis

More detailed version of  DH lecture by Dr. Papp

Speaker Dr. K. Papp
- a graduate of University of Calgary and Toronto
by Marie Smith

Dermatitis Herpetiformis has been around for as long as 1000 years.  It was first diagnosed by a German Doctor of dermatology, in 1884, as consisting of  very itchy, blistered bumps.

Dermatitis Herpetiformis was first associated with wheat in 1941 in Holland.  During the war, there was no grain products available.  It took only two years from 1939-1941 to realize that the incidence of not having wheat was beneficial to DH patients.  they appeared to clear up quite well.  Once grain was reintroduced to the diet, symptoms again appeared.

Of those afflicted with DH, the eruptions appear most commonly on the buttocks, elbows, knees, scalp, face, arms, and upper back.  Very unusual to appear on the hands.  We do not know why more men than women have Dermatitis Herpetiformis.

All people with Dermatitis Herpetiformis have small bowel disease, but for some reason not all people with Small Bowel Disease have Dermatitis Herpetiformis.

Dermatitis Herpetiformis is usually found second hand by small bowel biopsy.  Dermatitis Herpetiformis is mediated by the immune system.  You need genetics to get either Dermatitis Herpetiformis or celiac Disease.  A trigger is needed to set either one off.

How does it present?

Usually thought to be eczema, poison ivy, psoriasis, seborrhea, blistered skin, skin eruptions, or in very young children as a diaper rash.  Specifically, a constant irritating itch.  Also presented by a calcium and B-12 deficiency, blunted or flat villi.

Who are affected?

This is not really known, as not enough are affected for government to do a check. The only reason Great Britain and the U.S. have larger numbers is because they do more testing.

Diagnosis

  1. Clinical Presentation - As in how does it present?
  2. Regular biopsy - H & E biopsy - immunofluorescence testing.  Confusion of DH with IgA disease.  Needs fluorescence to see the difference.  IgA does not worsen with gluten.
  3. Biopsy has to be done by a dermatologist, on an appropriate lesion, or very near an eruption.
  4. If on a Gluten free diet for any length of time before a test, it will be negative.  Florescence was first used for DH in 1967-68.  Only three hospitals in Ontario use this technique, two in Toronto, and one in Hamilton.  Specimens must be properly prepared for diagnosis.

Treatment

  1. The Gluten free Diet is an avoidance.  It may take 2 to 10 years before DH eases.
  2. Dapsone - one dose may give some results.
  3. Sulfapyrdine Medication -  Dapsone alters how the body responds.  White cells infiltrate the skin.  The drug stops cells from leaving blood.  Dapsone is also used to treat leprosy.  
  4. Follow the Gluten Free Diet.
The side effects of Dapsone include rash, Gastro & blood changes, neurological numbness, & tingling.  These will reverse.  Dapsone is like a Band-Aid for rash, but does not help gut problems.  Dapsone should be started, then switch to Sulfapyrdine.  They do not cross react, and are for short term use.

Complications

Long term changes in gut and small bowel, also Lymphomas.

Follow Up

Blood test every 2-3 or 3-6 months.

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