Symptomatic dermatographism: current concepts in clinical practice with an emphasis on the pediatric population.

Symptomatic dermatographism reflects an exaggerated cutaneous response to the physical stimulus of pressure. Some consider it a common type of childhood physical urticaria. Its etiology can vary widely from drug reactions and infectious agents to systemic diseases and genetic inheritance. The mechanism is thought to be related to histamine degranulation due to a mechano-immunologic trigger, leading to the common symptoms of pruritus and burning in areas exposed to increased pressure, such as tight clothing, belts, and waistbands. The diagnosis typically is made with a blunt object such as a tongue blade or unopened ball-point pen pressed along the back and/or forearm, which elicits urtication. The mainstay of treatment is H1- and H2-receptor antagonists but also can include immunosuppressive agents, steroids, and phototherapy for refractory or severe cases.