Hives
Hives, known medically as urticaria, are raised red welts (bumps) or splotches on the skin that are usually caused by an allergic reaction, environmental factors, or stress, although some people get hives without an obvious cause. Hives can be acute, lasting less than 6 weeks, or chronic, occurring 2 or more times a week for more than 6 weeks. People who react to allergens may get hives frequently compared to others who may only get hives a few times ever. According to the American Academy of Allergy, Asthma, and Immunology, about 20% of the population will experience hives at some point in their lives.
Symptoms
Hives are often immensely itchy but might also sting or burn. They may cause swelling or puffiness in the surrounding skin, turn pale in the center when pressed, and vary in shape and size. They can show up anywhere on the body and may look different depending on the situation and person affected. Hives lesions typically evolve over minutes to hours and fade within 24 hours; however, they may be noticeable for several days or more.
Risk Factors
People with conditions like asthma, allergic rhinitis, and atopic dermatitis (eczema) may be more prone to developing hives. People may also be more prone to developing hives during periods of extreme stress.
Complications
Some people with hives may develop painful swelling of the lips, eyes, mouth, throat, and airways. People may also experience shortness of breath, wheezing, vomiting, and low blood pressure. These symptoms are indicative of anaphylaxis and can be life-threatening. The presence of any of these symptoms requires immediate medical evaluation and treatment. Learn more about anaphylaxis.
When to Seek Care
Hives don’t have to be present to have a medical evaluation; however, pictures of the lesions can provide insight that may be helpful for diagnosis. Providers can generally diagnose hives by inspecting the skin. In some situations, allergy testing can be helpful for people to know what allergens or environmental triggers they should avoid.
Contact a healthcare provider if:
- Hives or swelling last more than a week
- Lesions appear infected (red, swollen, pus-filled)
- Hives recur (reappear after they initially resolve)
- Itching interferes with activities of daily living
- Signs of anaphylaxis develop (wheezing, shortness of breath, vomiting, or swelling in the face, eyes, lips, mouth, or throat)
Treatment
Usually, hives will resolve without treatment, but a healthcare provider may recommend or prescribe medications that can help reduce the symptoms, like oral antihistamines or corticosteroids. Taking a cool bath or shower, wearing loose-fitting clothes, and applying cold compresses can also be beneficial. People with moderate to severe reactions may require administration of epinephrine and aerosolized bronchodilators. People with known allergies or a history of allergic reaction/anaphylaxis should carry an EpiPen (epinephrine injection) for immediate use.
Prevention
The best way to prevent hives is to avoid substances known to cause the reaction. This can include removing certain foods from the diet, limiting/eliminating exposure to airborne allergens, changing detergents or soaps to reduce exposure to dyes, avoiding extreme changes in temperature, wearing loose-fitting clothes, and lowering stress. It is also recommended to avoid taking aspirin-containing medications, narcotics, and alcohol as these can make the condition worse.
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