Dermatology 101: Dermatographism - The most interesting form of hives

Dermatographism showing a prominent raised hive following very light tracing on the skin with a tongue depressor.

Dermatographism showing a prominent raised hive following very light tracing on the skin with a tongue depressor.

Dermatographic Urticaria

Overview

Dermatographism is the most common form of inducible urticaria.  The diagnosis is a descriptive one describing hives (urticaria) induced by writing (graphism) on the skin (dermis). Unlike other forms of hives, itching is not frequently present.

Cause

The exact cause is unknown but the symptoms are a result histamine release from a special type of immune cell.  

Treatment

Asymptomatic cases may not require treatment.  H1 Antihistamines such as (Allegra and Zyrtec) taken daily can help prevent or blunt the effect of the dermatographism.  Avoiding trauma and wearing loose fitting clothing may help prevent exacerbations.