Approach Considerations
Dermographism can be distressing but is not life threatening. Patients with simple dermographism are asymptomatic and require no therapy. Patients with symptomatic dermographism should be treated until the problem is adequately controlled or resolved.
Recognition of the problem, avoidance of precipitating physical stimuli, reduction of stress and anxiety are important factors in medical care. In addition, scratching because of dry skin can be reduced through good skin care and the use of emollients.
Pharmacologic therapy
H1 antihistamines are the drugs of choice; however, higher-than-standard doses (up to 4-fold) are often required to achieve symptom control. In some patients, a combination of 2 antihistamines may be required. Sedating antihistamines such as hydroxyzine can be helpful. Regular treatment may have to be continued for several months. In a self-reported questionnaire of patients taking H1 antihistamines,18 (23%) of 79 were completely free from symptoms, 39 (49%) of 79 had a marked improvement, and only 3 (4%) of 79) reported no effect. [14] The addition of H2-receptor antagonists appears to result in little symptomatic benefit, although some studies have shown a further small reduction in the whealing response. [15]
Omalizumab, a recombinant humanized monoclonal antibody against immunoglobulin E (IgE), has been successfully used in patients with physical urticaria, including symptomatic dermographism. A 2018 review of the medical literature identified seven publications on omalizumab use in 54 patients with symptomatic dermographism. [16] A phase 2 placebo-controlled trial involving 55 patients showed that 72% of patients treated with 150 mg omalizumab and 58% patients treated with 300 mg omalizumab compared with 32% of placebo-treated patients improved at least 4 points in the Dermatology Life Quality Index (DLQI) scale, representing minimal clinically important difference. [17]
Adverse events appear generally low, with omalizumab being well tolerated by most patients, including children. Some patients have reported complete symptom resolution within days after the first injection. [18] Omalizumab was successfully used in a woman with three subtypes of chronic urticaria, including symptomatic dermographism. [19] Treatment was continued throughout the patient's pregnancy without any complications or obvious adverse effects, although the frequency of injections had to be increased to every 15 days.
Reinitiation of omalizumab treatment after relapse of disease appears to result in rapid and complete symptom control again after the first injection within the first 4 weeks, and no relevant adverse effects have been reported. [20]
Light therapy
Narrowband ultraviolet (UV)-B phototherapy and oral psoralen plus UV-A light therapy have both been used as treatments for symptomatic dermographism. Subjective relief of pruritus and whealing and objective reduction of wheals have been reported. [21] However, the improvement is short-lived, and most patients relapse within 2-3 months of completing phototherapy.
-
Dermographism or skin writing on forearm.
-
Appearance of the word "Dermatographia" on a human arm 15 minutes after the letters have been traced with a blunt object on the skin. A type of urticaria or "hives", also known as dermatographic urticaria, dermatographism, or "skin writing".
-
Dermographism urticaria. Courtesy of Professor Raimo Suhonen and DermNet New Zealand (http://www.dermnetnz.org/assets/Uploads/reactions/s/dermographism2.jpg).
