A Repeated Itchy Rash on Elbows or Knees: Eczema or Dermatitis Herpetiformis?
A new itchy rash on the elbows or knees might be blamed on workout clothing, kneepads or eczema. Another, less common possibility is dermatitis herpetiformis, a skin manifestation of celiac disease. The two conditions have different evaluations and care plans; appearance alone does not settle the question.
A name that can be confusing
Despite its name, dermatitis herpetiformis is not caused by the herpes virus, according to NIH MedlinePlus. It is associated with an immune response to gluten, a protein found in wheat, barley and rye. The rash can cause very itchy bumps or blisters, commonly in a symmetrical pattern. Scratching may make intact blisters hard to see.
Not everyone with this condition has obvious digestive symptoms. An NIDDK clinical overview noted that fewer than 20% of people with dermatitis herpetiformis reported symptoms of celiac disease in the source it reviewed. Estimates and individual experiences vary; the absence of digestive complaints does not rule it out.
| Situation | Next step |
|---|---|
| Repeated itchy bumps or blisters | Photograph them if practical and make a dermatology appointment. Note their locations and how long they last. |
| You are considering removing gluten | Discuss testing with a clinician first. A gluten-free diet can change celiac test results. |
| You already avoid gluten or have a wheat allergy | Tell the clinician. Do not reintroduce a food without individualized advice. |
| You have an established diagnosis | Follow the care plan from your clinician and dietitian; a moisturizer is not a replacement for that plan. |
What might an evaluation involve?
A dermatologist may use a skin biopsy and blood tests as part of the evaluation, depending on the clinical picture. NIDDK explains that the skin sample for direct immunofluorescence is commonly taken from skin adjacent to a lesion. Ask your clinician which tests fit your situation and what to do before testing.
Do not assume that eczema means a food allergy or that every athlete needs to eliminate gluten. Unnecessary dietary restriction can make eating and training harder, and it may complicate testing. Get prompt care for a rapidly spreading, painful or infected-appearing rash.
Read our related articles on eczema, food allergy and elimination diets and safer snack planning for youth sports.
Dr. Arsy Hydration Recovery Moisturizer #003 is a fragrance-free cosmetic moisturizer for dry, sensitive and eczema-prone skin. Follow the label; it does not replace medical treatment.
Sources and further reading
- NIH MedlinePlus: Dermatitis herpetiformis.
- NIDDK: Dermatitis herpetiformis overview.
- NIDDK: Celiac disease testing for healthcare professionals.
Educational information from Dr. Arsy; not a diagnosis or individual medical advice. The researchers and organizations cited do not endorse Dr. Arsy products.