Urticaria is a common disease with 20% of prevalence and marked effects on quality of life. The burden of chronic urticaria for patients, their family and friends, the healthcare system and society is substantial. Triggering of urticaria by infections has been discussed for many years but the exact role and pathogenesis of mast cell activation by infectious processes is unclear. The remission of annoying spontaneous chronic urticaria has been reported after successful treatment of persistent infections. Chronic viral infections including hepatitis B and C have been reported to be associated with CSU. More research is needed to make definitive recommendations regarding the role of infections and their management in case of urticaria and urticarial vasculitis. The routine screening of parasitic, bacterial or viral infections in CU is not recommended, however, testing a patient with urticaria for certain infections is a physician's choice based on the specific characteristics of the patient, such are clinical symptoms and laboratory results, dietary and cultural habits, country of origin and residency, traveling history.