What causes allergic urticaria?

Allergic urticaria is a skin allergic reaction caused by various factors. The main causes include: 1. Food allergy: Animal proteins such as fish, shrimp, seafood, milk, and eggs, as well as plant-based foods like strawberries and mushrooms, and even food additives such as salicylates, may trigger allergic reactions leading to urticaria. 2. Infectious factors: Infections caused by various viruses, bacteria, fungi, and parasites. These pathogens and their metabolic products may act as allergens, stimulating the body to produce allergic reactions. 3. Drug allergy: Medications such as penicillin, serum products, and vaccines, as well as preservatives and excipients within the medications, may also cause urticaria. 4. Inhalant and contact allergens: Inhalation of airborne particles such as pollen and dust mites, or contact with chemicals and insect venoms, may also trigger urticaria. 5. Physical factors: Physical stimuli such as cold, heat, sunlight, friction, and pressure may lead to the development of physical urticaria. 6. Psychological and endocrine factors: Emotional fluctuations, mental stress, depression, and other psychological factors, as well as disorders of the endocrine system, may also act as triggers for urticaria. 7. Systemic diseases: Chronic digestive system diseases, rheumatic fever, lupus erythematosus, tumors, and autoimmune thyroiditis may also be associated with the development of urticaria.