Causes of urticaria
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Pathophysiology and Immune Mechanisms in Urticaria
Urticaria is primarily caused by the activation and degranulation of mast cells in the skin, which release histamine and other inflammatory mediators, leading to the characteristic wheals and sometimes angioedema Chen2024Kolkhir2022Elieh-Ali-Komi2023. This process increases the permeability of subcutaneous capillaries, resulting in localized skin swelling . Both immunoglobulin E (IgE)-mediated and non-IgE-mediated pathways can trigger this mast cell activation .
Common Causes and Triggers of Urticaria
Infections
Infections are a leading cause of acute urticaria, especially in children, where they account for over half of cases . Viral infections, particularly respiratory tract infections, are well-recognized triggers for both acute and chronic urticaria in all age groups Kocatürk2023Imbalzano2015. In children, herpesviridae infections are most frequently associated, while hepatitis viruses are more common triggers in adults . Urticaria often resolves after the infection is controlled .
Allergens: Foods, Drugs, and Inhalants
Exposure to certain foods, medications, and inhalants can also cause urticaria, though these are less common than infections. In pediatric populations, food and inhalant triggers are more likely in those with underlying allergic diseases . Drug-induced urticaria is another recognized cause, particularly in acute presentations Techasatian2021Kolkhir2022.
Insect Stings
Insect stings are a rare but possible cause of urticaria, especially in children .
Chronic Urticaria: Autoimmune and Idiopathic Causes
Chronic urticaria, defined as symptoms lasting more than six weeks, is often idiopathic, meaning no clear cause is found in most cases Kolkhir2022Schaefer2017Wedi2009. However, up to half of chronic spontaneous urticaria (CSU) cases are believed to have an autoimmune basis, involving autoantibodies (IgG or IgE) that target mast cell or basophil receptors, leading to their activation Chen2024Bracken2019Asero2017+2 MORE. Other biological systems, such as inflammation and coagulation, may also contribute to the pathogenesis of chronic urticaria .
Less Common and Unproven Causes
There is currently no scientific evidence linking malignancy or persistent infections as direct causes of urticaria . Chronic urticaria is rarely associated with serious systemic diseases, but it can sometimes be a sign of underlying autoimmune conditions .
Conclusion
Urticaria is most commonly triggered by infections, especially in children, but can also be caused by allergens such as foods, drugs, and inhalants. Chronic urticaria is frequently idiopathic or autoimmune in nature, with mast cell activation as the central mechanism. While most cases are benign and self-limited, identifying the underlying cause is important for effective management, especially in persistent or severe cases Chen2024Techasatian2021Bracken2019+7 MORE.
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Most relevant research papers on this topic
How Infection and Vaccination Are Linked to Acute and Chronic Urticaria: A Special Focus on COVID-19
Viral infections and vaccinations, particularly COVID-19, can trigger and cause acute and chronic urticaria, with potential mechanisms including viral signals, medications, and stress.
Association between urticaria and virus infections: A systematic review.
Urticaria may be triggered by or primarily caused by viral infections, with herpesviridae infections being the most common in children and hepatitis virus infections in adults.
Acute and Chronic Urticaria: Evaluation and Treatment.
Urticaria is often self-limited and benign, with avoidance of triggers and pharmacotherapy being the mainstay of treatment.
Urticaria and infections
Successful treatment of persistent infections, particularly Helicobacter pylori, can significantly benefit patients with chronic urticaria.
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