Symptomatic Dermographism: A Systematic Review of Treatment Options

Background Symptomatic dermographism (SD), the most common form of chronic inducible urticaria, presents with transient wheals accompanied by itching in response to scratching. Little is known about available treatment options and their efficacy in SD. Objective To systematically review the efficacy of treatment options for patients with SD. Methods Using predefined search terms, we searched for relevant literature published until September 2019. The systematic review process was consistent with Preferred Reporting Items for Systematic Reviews and Meta-Analysis recommendations. Results The 23 studies identified included 15 randomized controlled trials; 22 and 17 assessed treatment responses in patients with SD by provocation/threshold testing and patient/physician clinical assessment, respectively. Thirteen different treatments were investigated in a total of 430 adult patients. The most frequently studied therapy, first-generation H1-antihistamines, showed variable efficacy and significant side effects. In contrast, second-generation H1-antihistamines (2ndAH1), in all studies, were effective and well tolerated. Monotherapy with an H2-antihistamine (AH2) was not effective, whereas adding an AH2 increased the efficacy of treatment with an H1-antihistamine (AH1). SD improved with omalizumab. All other treatments were only investigated in small, unrepeated, and/or uncontrolled studies. There are no studies on updosing of 2ndAH1. Conclusions The available SD studies are heterogeneous, mostly monocentric, old, small, and unrepeated, pointing to a high need for more and better studies. We suggest that 2ndAH1 should be the first-line treatment. In uncontrolled cases, the combination of AH1 and AH2 may be tried. Even though there is no evidence of its efficacy over standard dosage, updosing of 2ndAH1 may be considered based on the extrapolation of evidence from chronic spontaneous urticaria; omalizumab should be added in recalcitrant patients. Symptomatic dermographism (SD), the most common form of chronic inducible urticaria, presents with transient wheals accompanied by itching in response to scratching. Little is known about available treatment options and their efficacy in SD. To systematically review the efficacy of treatment options for patients with SD. Using predefined search terms, we searched for relevant literature published until September 2019. The systematic review process was consistent with Preferred Reporting Items for Systematic Reviews and Meta-Analysis recommendations. The 23 studies identified included 15 randomized controlled trials; 22 and 17 assessed treatment responses in patients with SD by provocation/threshold testing and patient/physician clinical assessment, respectively. Thirteen different treatments were investigated in a total of 430 adult patients. The most frequently studied therapy, first-generation H1-antihistamines, showed variable efficacy and significant side effects. In contrast, second-generation H1-antihistamines (2ndAH1), in all studies, were effective and well tolerated. Monotherapy with an H2-antihistamine (AH2) was not effective, whereas adding an AH2 increased the efficacy of treatment with an H1-antihistamine (AH1). SD improved with omalizumab. All other treatments were only investigated in small, unrepeated, and/or uncontrolled studies. There are no studies on updosing of 2ndAH1. The available SD studies are heterogeneous, mostly monocentric, old, small, and unrepeated, pointing to a high need for more and better studies. We suggest that 2ndAH1 should be the first-line treatment. In uncontrolled cases, the combination of AH1 and AH2 may be tried. Even though there is no evidence of its efficacy over standard dosage, updosing of 2ndAH1 may be considered based on the extrapolation of evidence from chronic spontaneous urticaria; omalizumab should be added in recalcitrant patients.