Urticaria (hives) is usually caused by allergic reactions or bodily sensitivities and is generally not contagious from person to person. If you experience symptoms, it is recommended to identify the cause and consult a doctor promptly.

Specific reasons may include:

1. Food or medication effects: Some people experience an immune system reaction after consuming seafood, nuts, or taking certain medications, which can trigger skin rashes and itching.
2. Environmental factors: Contact with pollen, dust mites, or physical stimuli such as temperature changes or sunlight exposure may induce local skin abnormalities.
3. Infection and internal condition: Viral colds, excessive stress, or fatigue may cause fluctuations in the body's immune system, resulting in urticaria symptoms.
In daily care, you can keep a record of your diet and activities to help identify potential triggers; avoid scratching your skin and wear loose cotton clothing to reduce friction. If flare-ups recur, please see a dermatologist for a professional examination. The doctor will recommend antihistamines or other soothing methods based on the situation. Maintaining a regular sleep schedule and moderate exercise also help maintain a stable physical condition.