Doxycycline Evaluated in Patients with Potentially Life-Threatening Form of Chronic Urticaria
(HealthDay News) — Just over one-third of chronic cold urticaria patients benefit from treatment with doxycycline, according to a research letter published online June 25 in the British Journal of Dermatology.
Marina Gorczyza, from Charité Universitätsmedizin Berlin, and colleagues assessed the effects of antibiotic treatment in 26 patients (20 female; mean age, 41 years; mean disease duration, 7.2 years) with cold urticaria. All patients were treated with doxycycline 200 mg/day for a mean of 18.5 days. Cold provocation tests with TempTest 3.0 (24 patients), ice cube test (one patient), or 15-degree C hand bath (one patient) were used to assess treatment response before and 10 minutes after therapy.
The researchers found that doxycycline treatment did not significantly reduce critical temperature thresholds (CTTs) of cold urticaria patients (baseline 14 degrees C versus post-treatment 12 degrees C; P = 0.5). However, full remission (no wheal development after provocation with 4 degrees C after treatment) in response to therapy was seen in a subpopulation of cold urticaria patients (19 percent). Partial responses were seen in another 15 percent of patients (CTT reduction of ≥4 degrees C after therapy). Disease duration or severity, age of the patients, and duration of the treatment were not associated with treatment responses to doxycycline, although complete responders had lower pre-treatment CTTs than partial responders (P = 0.01).
"Further studies should be done to investigate the mechanism of action and the duration of treatment responses, and to identify markers that allow for treatment outcome prediction," the authors write.