Dermographism is a common form of chronic hives called physical urticaria, which gets its name because the hives are caused by a certain stimulus on the body. In this case, the stimulus is stroking the skin with an object. Dermographism is also known as "skin writing" and it occurs in about 5% of the population. A person who gets dermographism usually has it for several years, and then it goes away on its own.
Appearance of DermographismPeople with dermographism will get an itchy hive within minutes of scratching the skin or at sites of friction with clothes, such as under collars or cuffs. A dermographism hive doesn't have the typical round appearance you see with regular hives. Instead, this hive is straight like a line, and it goes away within hours.
Dermographism tends to occur in bouts. A person might get hives frequently for a period of time, but then occurrences may space out and appear to stop for some time only start up again at a later date.
DiagnosisDermographism is diagnosed clinically based on the typical appearance of the rash. To make the diagnosis, the doctor may take a tongue blade and draw it over the skin of the arm or back to cause a hive.
TreatmentUnless the skin is highly sensitive and reacts frequently, treatment is not needed. If hives are occurring frequently, an antihistamine like Zyrtec, Claritin, Allegra, or Hydroxyzine may be recommended.
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Habif, Thomas. "Urticaria and Angioedema." Clinical Dermatology, 4th Edition. Ed. Thomas Habif, MD. New York: Mosby, 2004. 129-61.