What Is Dermatographism?

Dermatographism is a skin reaction in the hives family

Appearance of the word "Dermatographia" on a human arm 15 minutes after the letters have been traced with a blunt object on the skin. A type of urticaria or "hives", also known as dermatographic urticaria, dermatographism, or "skin writing".
R1carver/Wikimedia Commons/CC-BY-SA-3.0

People who have a physical urticaria, a raised skin rash also known as hives, often have a physical trigger such as pressure, heat, cold, sunlight, water, or exercise that causes their skin to react. Up to 20 to 30 percent of people with chronic urticaria (hives lasting more than six weeks) have a physical cause.

What Dermatographism Is

Dermatographism means the ability to write on the skin. Approximately 5 percent of the population lives with dermatographism.

People with this form of chronic urticaria are sensitive to touch and pressure, as well as scratching. The areas of skin that are touched or scratched get a raised, red and itchy rash. While many people with chronic urticaria have some features of dermatographism, for people with true dermatographism, pressure is the only trigger for their symptoms.

In some forms of dermatographism, symptoms occur after within a few minutes of stroking the skin with an object (such as a pen or tongue depressor), with the rash going away without treatment within an hour. Other forms of dermatographism, such as delayed pressure urticaria, result in a burning sensation and pain that may last for hours after the pressure was applied. Most dermatographism episodes manifest five to seven minutes after stimuli and take 15 to 30 minutes to clear. People with dermatographism may notice their dermatographism developed suddenly, lasts for several years, and then goes away on its own.

Doctors are not sure why dermatographism occurs. It may be a true allergy, meaning that allergic antibodies are present in the body that causes the reaction, but it is unknown what the antibodies are targeted against. It may also be caused by the immune system releasing too much histamine, which can cause red welts and hives.


Diagnosing and Treating Dermatographism

A dermatographism diagnosis can be made by stroking the skin with an object, such as a pen. The appearance of a red, itchy, and sometimes raised rash along the area of the pen stroke can alert your doctor to dermatographism. Delayed pressure urticaria is diagnosed by placing a weight on the skin or over the shoulder (such as a heavy backpack) for a certain period of time, with an area of swelling and redness appearing for a few hours and possibly lasting for days.

If you are not bothered by dermatographism, then no treatment is needed. Symptoms can be decreased with the use of various antihistamines. Many of the antihistamines that cause sedation, including hydroxyzine, seem to work especially well; however, there are non-drowsy formulas of antihistamines as well. 


American Osteopathic College of Dermatology. Dermatographism. 2017. 

Continue Reading