Symptomatic dermographism in Thai patients

Abstract

Background : Symptomatic dermographism (SD) is a type of physical urticaria in which the patient has hyperreactivity to a stroke or scratch applied to the skin which produces an itchy wheal. There is no data concerning the incidence of symptomatic dermographism in the Thai population.

Materials and methods : We retrospectively reviewed the medical records of patients attending the urticaria clinic of the Department of Dermatology, Siriraj hospital, Mahidol University, during the period January 2000 - December 2001. Demographic data, causative agents, aggravating factors, the natural course of the phenomenon and treatment were analyzed.

Results : Twelve cases were diagnosed with SD. All were women, with an age range from 12 to 61 years (mean± SE=36.9±4.42 years). A possible cause was found in 1 out of 12 cases (8.3%). This was carcinoma of the sigmoid colon. Other co-incidental findings in other patients were a positive personal history of atopy in 4 cases (33.3%) and a positive family history of atopy in 4 cases (33.3%), dental caries in 2 cases (16.6%), dyspepsia in 2 cases (16.6%), one each case (8.3%) of diabetes mellitus, myoma uteri, and eosinophilia.  Our patients   responded

well to H  antihistamines, which were second and third generation antihistamines in the majority of cases. Clinical improvement was seen in 3-6 months. Some needed the addition of doxepin, a tricyclic antidepressant. The average duration of the disease was 55.6 months.

Conclusions : The prevalence of SD in Thai patients presenting to our dermatology clinic was low when compared with other studies. Most patients had no associated conditions, and responded to the usual regimen for treatment of urticaria . A geographically-based study is furthur recommened.