Dermographic urticaria(DU)is a subtype of urticaria characterized by strong itch and wheals induced by mechanical scratching. Oral histamine H1-receptor antagonist (antihistamine) is recommended as the first line treatment and may reduce symptoms of a certain population of the patients. However, DU of many patients are refractory to antihistamines and seriously impair their QOL.
Several medications, such as high dose antihistamines, montelukast and cyclosporine, are suggested as the second line therapies in all Japanese, European and American guidelines. However, clinical evidences of these treatments were mostly obtained for chronic spontaneous urticaria, and the effectiveness of them has not been specifically studied on DU. We here report 27 cases of antihistamine-resistant DU treated with the second line medications suggested in the guidelines.
B) Methods:
Thirty-five patients who visited Hiroshima University Dermatology clinic from January 2009 to April 2015 for the treatment of DU were studied retrospectively.
C) Results:
DU in 27 patients were refractory to standard doses of antihistamines. However, all or most symptoms disappeared in 7 out of 27 patients who increased the dose of an antihistamine up to twice. Ten out of 21 patients who were treated with both an antihistamine and montelukast cleared the symptoms. Other 10 patients whose symptoms had not subsided by high doses of antihistamines and montelukast additionally took cyclosporine. In six of them, most symptoms diminished, but two of them did not show any change. The other two patients dropped out because of side effects.
D) Conclusions:
Approximately 77% (27 out of 35) of the patients with DU was refractory to a standard dose of antihistamine. However, 85 % (23 out of 27) were satisfactorily treated by a higher dose of antihistamine and/or a combination with other medications. The second line treatments suggested in the guidelines for urticaria are worth trying for DU refractory to antihistamines.