Rash

[Ellen V. Nelson]

Hello, all. Although I am very strict about my gluten-free diet, I get rashes behind my knees. When I have them biopsied, the dermatologist reports they are bug bites. I don’t agree with this diagnosis as these are like blisters with fluid inside. Does anybody else deal with this? I was diagnosed with Celiac two years ago with positive blood work and the endoscopy.

[trents]

Welcome to the forum, Ellen!

If they were bug bites, why would they only show up behind the knees? From your description of the bumps, it sounds like it could very well be dermatitis herpetiformis  ("DH"), a rash whose only known cause is celiac disease. When a biopsy is done for DH, my understanding is that the tissue samples need to be taken from between the bumps, not on them. Many dermatologists don't know anything about DH and so either don't biopsy them correctly or don't know what tests to order.

 

Edited July 31, 2023 by trents

[trents]

How to correctly biopsy DH: https://www.mdedge.com/familymedicine/article/27546/dermatology/biopsy-location-key-dermatitis-diagnosis

[Ellen V. Nelson]

Thank you so much for this. I am truly racking my brain to think of where I could have ingested gluten. I am so careful-the rash is a real setback.

[Russ H]

In addition to what trents has posted above, it can take 2 years or more to recover from dermatitis herpetiformis. Your rash could also be something else such as weeping eczema or an allergic reaction.

[trents]

Ellen, it might be wise to go back to your dermatologist armed with new information and request another biopsy done correctly. Or, seek out another dermatologist who is competent to perform a biopsy correctly.