What to do if you suddenly develop hives

Generally, sudden onset of rashes may be caused by factors such as exposure to allergens, temperature changes, acute urticaria, rubella virus infection, or systemic lupus erythematosus. It is recommended to seek medical attention promptly, identify the underlying cause, and receive symptomatic treatment under a doctor's guidance. Specific causes are analyzed as follows:

1. Exposure to allergens: Contact with allergens such as pollen, dust mites, or cosmetics can trigger an immune response leading to rashes accompanied by itching. Immediately avoid the allergen, rinse the affected area with clean water, and take antihistamines such as cetirizine hydrochloride tablets, loratadine syrup, or ebastine tablets as directed by a physician.

2. Temperature changes: Sudden environmental temperature fluctuations can cause abnormal constriction and dilation of skin blood vessels, triggering rash similar to urticaria. Maintain proper warmth or cooling, avoid drastic temperature changes, wear loose and breathable clothing, reduce skin friction, and the rash usually resolves on its own.

3. Acute urticaria: Caused by food, medication, or infections leading to edema of the skin and mucous membranes, characterized by sudden appearance of wheals with significant itching. Avoid scratching, apply calamine lotion topically as prescribed, and take oral medications such as chlorpheniramine maleate tablets, fexofenadine hydrochloride tablets, or desloratadine dry suspension under medical guidance.

4. Rubella virus infection: After infection with the rubella virus, fever appears first, followed by light red rashes all over the body, commonly seen in children. Home isolation is required until the rash subsides. Use physical methods to reduce fever; take medications such as acetaminophen suspension drops, ibuprofen granules, or pediatric paracetamol-phenyl-cold granules as directed by a doctor.

5. Systemic lupus erythematosus: An autoimmune disorder causing systemic damage, with skin manifestations such as butterfly-shaped rashes or urticarial-like eruptions, often accompanied by fever and fatigue. Follow medical advice to use medications such as prednisone tablets, methotrexate tablets, and hydroxychloroquine sulfate tablets. In severe cases, intravenous immunoglobulin therapy may be administered to modulate immune function.

Maintain a light diet and avoid spicy foods, seafood, and other allergenic foods. Keep the skin clean and use gentle skincare products. Follow a regular作息 (sleep-wake) schedule to enhance immunity, avoid excessive fatigue, and support recovery from skin symptoms.