Treatment may not be needed if the hives are mild. They may disappear on their own. To reduce itching and swelling:

• Avoid hot baths or showers.
• Avoid irritating the area with tight-fitting clothing.
• Take antihistamines. Diphenhydramine is considered the most effective.

If your reaction is severe, especially if the swelling involves your throat, you may require an emergency shot of epinephrine (adrenaline) or steroids. Hives in the throat can block your airway, making it difficult to breathe.

Hives may be uncomfortable, but they generally are harmless and disappear on their own. In most cases, the exact cause of hives cannot be identified.

• Anaphylaxis (a life-threatening, whole-body allergic reaction that causes breathing difficulty)
• Swelling in the throat can lead to life-threatening airway blockage

Call 911 or your local emergency number if you have:

• Fainting
• Shortness of breath
• Tightness in your throat
• Tongue or face swelling
• Wheezing

Call your health care provider if the hives are severe, uncomfortable, and do not respond to self-care measures.