Objective: Although symptomatic dermographism (SD) is the most common subtype of chronic inducible urticaria (CIndU), little is known about the differences between SD and chronic spontaneous urticaria (CSU). Information about the etiopathogenesis and underlying causes of SD are scarce. In our study, we aimed to evaluate the differences between the SD and CSU in terms of demographic, clinical, laboratory characteristics, and comorbid conditions.

Materials and Methods: This was a retrospective study and we examined the medical records of CSU and SD patients referred to our Urticaria Center of Reference and Excellence center. Differences in demographic and clinical characteristics, laboratory parameters, accompanying conditions, and response to standard doses (single dose) of second-generation antihistamines (sg-AH) between the SD and CSU groups were determined. Treatment responses were evaluated by the urticaria control test (UCT).

Results: A total of 856 patients (231 with SD and 625 with CSU) were included in the analysis. Patients with SD were younger (age; median 34 vs 37; p<0.001) and had less accompanying systemic symptoms (4.3% vs 25%; p<0.001) than patients with CSU. Systemic diseases (36.7% vs 27.4% vs p=0.017), elevated C-reactive protein and erythrocyte sedimentation rate and positive anti-thyroid peroxidase antibody were found to be more frequent in CSU patients compared to SD patients (p<0.001, p=0.003, p=0.03). Accompanying atopy, stress and infections were found to be similar between the two groups (p>0.05; for all). Patients with SD showed better response to standard doses of sg-AHs than patients with CSU (UCT ≥12 in 59.6% vs 47.4%; p=0.005).

Conclusion: SD differs from CSU in terms of fewer systemic components and better response to antihistamines.