What should you know about giant hives?

Hives are raised, itchy areas that can join together into broad patches. Individual welts may change shape or appear in new places while the episode continues. Angioedema presents with deeper swelling, often around the lips, eyelids, hands, feet, or throat, and may accompany hives.

Triggers can include an infection, food, medicine, heat, pressure, or a cause that is not identified. A history of timing, new exposures, and associated symptoms helps distinguish hives from other rashes.

Move away from a suspected trigger when possible and keep the skin cool. Wear loose clothing and avoid scratching, hot showers, and strenuous activity until symptoms settle. Photograph the rash and note when each flare began, how long welts lasted, and whether swelling affected the mouth or eyes.

An antihistamine treatment is commonly used for itchy hives when suitable for the person. An oral corticosteroid treatment may be prescribed for selected severe flares. Use medicines as directed, and do not test a suspected food or medicine at home.

Call emergency services immediately for difficulty breathing, wheezing, throat tightness, tongue swelling, faintness, sudden weakness, or trouble swallowing. These signs can indicate a serious allergic reaction. Seek same-day medical advice for rapidly spreading hives, repeated episodes, painful swelling, or symptoms that do not settle with the advised plan.

Ask whether the pattern fits hives or another rash, whether angioedema is present, which triggers to avoid, what medicine to use at the first sign, and what emergency plan your household should follow.