Dermographism is the most common form of physical urticaria and manifests as an exaggerated wheal and flare reaction of the skin induced by pressure. In dermographism, inadvertent stroking or rubbing of the skin will result in corresponding linear wheals. The wheals usually persist for about 15-30 minutes. The condition is usually asymptomatic, but some forms are associated with pruritus. The exact cause of dermographism is unknown, but clinically it appears similar to urticaria. Agents that are known to cause or exacerbate urticaria also may cause dermographism (eg, angiotensin converting enzyme [ACE] inhibitors).

An increased incidence has been reported during pregnancy and in individuals with Behçet syndrome, thyroid disorders, infections, and atopic dermatitis. Dermographism affects approximately 2%-5% of the population and is more common in young adults.