Hives (Urticaria)

Introduction to Hives

The medical term for hives is urticaria. Hives are pink welts or swellings that can burn, itch, and/or sting. Hives can vary in size from as small as a pen tip to as large as a dinner plate. Generally, hives resolve on their own within 24 hours. Hives can appear on any part of the skin. When the hives appear around the eyes, lips, or genitals, swelling may be greater than normal. Anyone can get hives. Hives are typically the result of an allergic reaction; however, there are many nonallergic causes. Finding the exact cause can be difficult. In some cases, testing, such as allergy tests, bloodwork or a skin biopsy may be helpful.

Causes of Hives

Anyone can develop hives, with approximately 10 to 20 percent of people experiencing at least one episode in their lifetime. Hives are often triggered by an allergic reaction, but there are many nonallergic causes as well. Common causes include:

  • Allergic Reactions: These can be triggered by foods, medications, insect stings, or other allergens.
  • Nonallergic Triggers: Stress, infections, exercise, sun exposure, and temperature changes can also cause hives.
  • Infections: Upper respiratory infections, colds, and various bacterial, viral, or fungal infections can lead to hives.

Types of Hives

Hives can be classified into different types based on their duration and triggers:

  • Acute Hives: These are usually the result of an allergic reaction and may appear within minutes to hours after exposure to the trigger. Acute hives typically last less than six weeks.

  • Chronic Hives: When hives persist for more than six weeks, they are considered chronic. This condition may be linked to underlying health issues, such as autoimmune disorders.

  • Physical Hives: These hives are caused by physical stimuli such as sunlight (solar urticaria), cold (cold urticaria), pressure, or friction (dermographism).

Diagnosing and Treating Hives

Diagnosing the cause of hives can be challenging, and your dermatologist may recommend various tests, including allergy tests, blood work, or a skin biopsy.

Treatment options include:

  • Antihistamines: Over-the-counter antihistamines can help relieve itching and reduce the appearance of hives. In cases where these are not effective, your dermatologist might prescribe stronger antihistamines or combine them with other medications.

  • Corticosteroids: For severe cases, corticosteroids may be prescribed to reduce inflammation. However, they are generally used for short periods due to potential side effects.

  • Biologics: In cases of chronic idiopathic urticaria (CIU), a biologic medication such as omalizumab may be prescribed.

If you experience hives that do not go away within 24 hours or have difficulty breathing or swallowing, seek immediate medical attention. A board-certified dermatologist can help diagnose the cause of your hives and recommend an appropriate treatment plan.