What is dermatographism?
Dermatographism is a common, benign skin condition. People who have this condition develop welts or a localized hive-like reaction when they scratch their skin. It can also happen when the skin is exposed to pressure or rubbing. This condition is also called skin writing, dermographia, or dermatographic urticaria.
How common is dermatographism?
Dermatographism affects about 2% to 5 % of the general population.
Symptoms and Causes
What are the causes of dermatographism?
Dermatographism is most likely caused by an inappropriate release of histamine in the absence of a typical immune signal. The red welts and hives are caused by the local effects of histamine.
Other causes include:
- Cold exposure
A person with dermatographism may also have an allergy to an external substance. However, this is uncommon.
What are the symptoms of dermatographism?
The symptoms of dermatographism vary from person to person. Symptoms of dermatographism include:
- Raised red lines
- Hive-like welts
Diagnosis and Tests
How is dermatographism diagnosed?
Dermatographism appears within 5 to 7 minutes after skin is irritated. If the skin is stroked and hives appear, they will occur in the same direction and orientation as the irritation. The doctor will likely use a tongue depressor to scratch or press on the skin of your arm or back and see if welts appear a few minutes later.
Management and Treatment
What are the treatments for dermatographism?
Symptoms of dermatographism usually go away within 30 minutes. If they do not go away, treatment includes use of antihistamines. In addition, moisturizers and proper skin care can help to soothe dry, itchy skin.
What are the complications of dermatographism?
Generally, dermatographism leaves no lasting marks, causing only minor, short-lived irritation and symptoms.
How can you prevent dermatographism?
Dermatographism can be prevented by:
- Wearing loose-fitting clothing
- Avoiding interaction with very hot water
- Using a towel to pat dry after bathing
- With a doctor’s permission, refraining from use of a drug if that is the cause of dermatographism
Outlook / Prognosis
What is the prognosis/outlook for patients who have dermatographism?
For patients who have dermatographism, the condition may last anywhere from months to years, or last throughout their lives. For many, it clears up in a year or two, or in such a way that the skin irritation does not create substantial symptoms.
Who is at risk of developing dermatographism?
Dermatographism is most common in young adults. Generally, people with this condition are healthy and live a normal life.