Dermatographic urticaria

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Dermatographic urticaria
Classification & external resources
Dermatographic urticaria is sometimes called "skin writing".
ICD-10 L50.3
ICD-9 708.3
OMIM 125635
DiseasesDB 12736
eMedicine derm/446 

Dermatographic urticaria (also known as dermographism, dermatographism or "skin writing") is a skin disorder seen in 1.5 to 23.5 percent of the population[1], in which the skin becomes raised and inflamed when stroked or rubbed with a dull object[2]. Dermatographic urticaria is caused by mast cells in the surface of the skin releasing histamines without the presence of antigens, due to the presence of a weak membrane surrounding the mast cells. The histamines released cause the skin to swell in the affected areas.

This weak membrane easily and rapidly breaks down under physical pressure causing an allergic-like reaction, generally a red welt to appear on the skin. It can often be confused with an allergic reaction to the object causing a scratch, when in fact it is the act of being scratched that causes a welt to appear. These welts are a subset of hives that appear within minutes, accompanied by a sensation of burning, and/or itchiness. The first outbreak of hives can lead to others on body parts not directly stimulated, scraped or scratched. The redness and swelling stays from anywhere upwards of 10 minutes. Often this leads to difficulty sleeping, irritability, and general discomfort.

It can be treated by antihistamines or cromoglicate, as they prevent the histamine from causing the reaction. The underlying cause of dermographism is not known, and can last for many years without relief. 95% of chronic cases are never solved. Sometimes the condition goes away, sometimes it stays forever. It is not a life threatening disease.

[edit] References

  1. ^ Jedele KB, Michels VV. "Familial dermographism." American Journal of Medical Genetics 1991;39:201–3.
  2. ^ Kontoi-Fili K., Borici-Mazi R., Kapp A., et al. "Physical urticaria: classification and diagnostic guidelines." An EACCI position paper. Allergy 1997;52:504–13.

[edit] External links