Dermographism: Writing on the skin
The cause of dermographic urticaria is unknown, but appears to be related to a mast cell abnormality and is probably autoimmune in nature.
Due to a recent illness, I developed dermographism. Translated, dermographism means skin writing. It is a type of urticaria that usually occurs in teenagers and younger adults and can last a few weeks to a lifetime. Those that develop it later in life do so usually from trauma or an illness. It affects approximately 2% to5% of the population. There does not appear to be a racial predication or gender specificity, although there is some research that suggests females may be slightly more affected than males.
Also known as dermographic urticaria, the cause of this illness is unknown, but appears to be related to a mast cell abnormality and is probably autoimmune in nature. It is theorized that it is a histamine reaction, released by mast cells on the surface of the skin. Stress, infection, emotion, exercise, heat, and antibiotics such as penicillin can trigger a reaction. When patients with dermographism lightly scratch the surface of their skin, the area reddens and develops a wheal. This usually disappears completely with 30 minutes but has the potential to last for days.
Clinicians can diagnose dermographism easily by using a tongue depressor. Run it over the surface of the patient's skin. In a few minutes, a wheal should appear where the skin has been touched. Patients with dermographism have been known to use this nuisance creatively. One artist etches elaborate drawings and photographs them before they disappear.
Dermographism is usually treated with antihistamines to stop the reaction. The treatment uses a combination of H₁ antagonists and H₂ receptor antagonists. Statistically, about half of patients see marked improvement, though others may see no improvement at all. Patients should avoid harsh soaps, wool clothing that might irritate the skin, and scratching. Moisturizing the skin can be helpful. Sedating antihistamines such as hydroxyzine can be useful for those with symptoms that are keeping them from sleeping.
The differential diagnosis includes chronic urticaria, systemic mastocytosis and urticaria pigmentosa as well as latex allergy.
Dermographism is not life threatening but it can be troubling for those experiencing the symptoms. Young patients may be embarrassed when an outbreak occurs. Clinicians should reassure their patients that this is not life threatening and can be properly managed. Referrals to a dermatologist or allergist are recommended.
Sharon M. O'Brien, MPAS, PA-C, is a practicing physician assistant and health coach in Asheville, NC.
For more information, visit https://www.dermnetnz.org/topics/dermographism/
- Joanna Wallengren and Anders Isaksson. Urticarial Dermographism: Clinical Features and Response to Psychosocial Stress. Acta Derm Venereol 2007; 87: 493–498.
- Taskpan O., Harmanyeri Y, Evaluation of patients with symptomatic dermographism. J Eur Acad Dermatol Venereol. 2006 Jan;20(1):58-62.
- Dice, John P., Gonzalez-Reyes, Erika. UptoDate. Physical Urticarias.Dermographism.