I Have Hives from Scratching! Am I Allergic to Myself?
Q. I’ve noticed recently that when I scratch myself I’m breaking out in hives in that area! Am I allergic to myself, should I be worried? What type of treatment is available for this?
A. No you are not allergic to yourself; exposure to certain types of physical stimuli like pressure (like scratching yourself), cold, and heat can cause hives. Doctors refer to this type of skin condition, which accounts for nearly 20 percent of hives as physical urticaria (the medical term for hives). One of the most common mechanisms of physical urticarial that has been identified is dermatographism. The name of this skin condition means “skin writing” in Greek (derma is “skin”, graphe is “writing”). The ability to write letters or symbols by stroking your skin (with your fingernails or a retracted ball point pen, for example), which results in blanching (whitening of your skin) that’s followed by redness and swelling (hives), is the most obvious sign of this often harmless form of hives. Dermatographism affects approximately 5 percent of the U.S. population and can persist for years until the outbreaks disappear. Common triggers for dermatographism include rubbing, scratching, or stroking the skin. Tight clothing or pressure from leaning against hard surfaces (a chair or desk) can also cause this form of hives. A rarer, more severe form of dermatographism can occur following bacterial, fungal, or scabies infections, or after treating a bacterial infection with penicillin. If you feel you have any of these then you should speak to your allergist.