2024年10月1日 · Chronic hives are welts that last for more than six weeks and return often over months or years. Often, the cause of chronic hives isn't clear. The welts often start as itchy patches that turn into swollen welts that vary in size.

2023年10月27日 · Hives — also known as urticaria (ur-tih-KAR-e-uh) — is a skin reaction that causes itchy welts that range in size from small spots to large blotches. Hives can be triggered by many situations and substances, including certain foods and medications. Angioedema can arise with hives or alone.

2024年10月1日 · Where hives appear and how long it takes a welt to fade and whether it leaves behind a bruise or other mark. Whether your hives come with painful swelling. You also may need blood tests to determine the cause of your symptoms.

2023年10月27日 · To diagnose hives or angioedema, your doctor will likely look at your welts or areas of swelling and ask about your medical history. You may also need blood tests or an allergy skin test. Treatment. If your symptoms are mild, you may not need treatment. Hives and angioedema often clear up on their own.

2016年2月16日 · Hives (urticaria) are raised, red or white itchy welts on your skin. A sudden onset of hives (acute hives) usually has an identifiable cause or trigger — such as insect stings or bites, medications, certain foods, allergens, or infections.

2017年3月24日 · Chronic hives are a condition in which the welts last more than six weeks or recur over months or years. Chronic hives usually aren't life-threatening, but the condition can be very uncomfortable and interfere with sleep and daily activities.

2021年12月15日 · Cold urticaria (ur-tih-KAR-e-uh) is a skin reaction to cold that appears within minutes after cold exposure. Affected skin develops itchy welts (hives). People with cold urticaria experience widely different symptoms. Some have minor reactions to the cold, while others have severe reactions.

2024年10月23日 · Dermatographia is a condition in which lightly scratching your skin causes raised, inflamed lines or welts. These marks tend to go away in less than 30 minutes. The condition is also known as dermatographism and skin writing.

2018年12月29日 · For the past five nights, including tonight, I have been experiencing a reaction of some sort. I assume that they are hives. The weird thing is that it only happens, well 95% of the time, the breakout starts in the evening. I know it's not from a bite or something because they are in different spots each night...

Illustration of hives on different skin colors. Hives can cause swollen, itchy welts. Hives also is called urticaria.