Association between giardia lamblia infection and the occurrence of chronic urticaria in children in Kirkuk: A case-control study

Background: Chronic Urticaria (CU) is a debilitating condition affecting 0.5-5% of children globally. In Kirkuk, Iraq, high rates of intestinal parasitic infections (31.7% prevalence) and endemic Giardia lamblia (6.4-30.9%) suggest a potential link to CU via IgE-mediated mast cell activation and epithelial barrier dysfunction.Objective: To evaluate the association between G. lamblia infection and CU in children, and assess immunological correlates.Materials and Methods: A case-control study (2024-2025) included 140 CU patients and 42 healthy controls (age/gender-matched). Stool samples were analyzed microscopically for parasites; blood samples quantified CBC parameters and total IgE (ELISA).Results: G. lamblia prevalence was significantly higher in CU patients (17.1% vs. 4.8%; p<0.05). CU patients exhibited elevated total IgE (mean 361.05 ng/ml vs. 186.31 ng/ml; P=0.001), with Giardia-positive cases averaging 442.8 ng/ml. CU patients showed higher rates of abdominal pain (75.71%), fever (78.57%), and itching (72.86%) vs. controls (p<0.001). Hematological indices (platelets, WBCs, neutrophils, lymphocytes, monocytes) also differed significantly (p<0.05).Conclusion: G. lamblia infection is significantly associated with CU in children, likely via IgE-mediated immune activation. Routine parasite screening is recommended for pediatric CU in endemic regions.