Parasitic Infections in Children with Chronic Spontaneous Urticaria.

BACKGROUND Parasites have been proposed to be an underlying cause of chronic spontaneous urticaria (CSU) in childhood, but a clear causal relationship between them has not been established. This study aimed to investigate the prevalence of parasitic infection-related CSU (PIRCSU) in children and to determine the factors associated with PIRCSU. METHOD Data from 211 children with CSU were analyzed. Information on stool examination, antiparasitic medications received, and response to treatment was recorded. The disappearance of urticaria for more than 6 months is defined as remission, and remission of urticaria after antiparasitic treatment is defined as PIRCSU. RESULTS Parasites were detected in 21 (10%) patients. Blastocystis hominis was the most common parasite. After antiparasitic medication, all samples became normal; urticaria continued in 5, was reduced in 6, and disappeared in 10 patients. The latter 10 patients were considered as cases of PIRCSU (4.7%). The erythrocyte sedimentation rate was significantly higher in patients with PIRCSU than in those without [8.5 mm/h (3.5-14.5) vs. 2 (0-7), p = 0.011]. Gastrointestinal complaints were significantly more frequent in patients with PIRCSU than in those without. The occurrence of abdominal pain was a significant risk factor that increased the probability of PIRCSU [OR = 6.60, 95% CI = 1.35-32.23, p = 0.020]. CONCLUSION Parasites may cause CSU even in nontropical countries, and remission may only be possible with the treatment of the parasitic infection. The occurrence of abdominal pain points to parasitic infection in patients with CSU. Therefore, we suggest that parasites should be investigated routinely, especially if the patient has gastrointestinal symptoms of CSU in childhood.