Dermatographism on the arm

Dermatographism on the arm

Dermatographism is a condition where lightly scratching the skin raises wheals or welts. Histamine is released at the site, causing the small blood vessels (capillaries) to dilate, producing redness and localized swelling.


Review Date: 04/27/2006
Reviewed By: Michael Lehrer, M.D., Department of Dermatology, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network.


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