Hives, also known as urticaria, are a common skin condition characterized by itchy, raised welts or bumps that vary in size and appear anywhere on the body. These welts can be red, pink, or skin-colored and often appear suddenly.
Causes:
Hives occur when certain cells in the skin release histamine and other chemicals into the bloodstream. This release can be triggered by a variety of factors, including:
- Allergens: Foods (e.g., peanuts, shellfish, eggs, milk), medications (e.g., penicillin, aspirin), insect stings, latex.
- Physical stimuli: Pressure, cold, heat, sunlight, vibration, exercise. This is known as physical urticaria.
- Medications: Prescription and over-the-counter drugs.
- Infections: Viral, bacterial, or fungal infections.
- Insect bites and stings.
- Contact with certain substances: Plants (e.g., poison ivy), chemicals.
- Stress.
- Autoimmune conditions.
- In some cases, the cause of hives cannot be identified (idiopathic urticaria).
Symptoms:
The primary symptom of hives is the appearance of welts (wheals) on the skin. These welts can:
- Be itchy (pruritic), sometimes intensely so.
- Vary in size, from small spots to large patches.
- Appear anywhere on the body, including the face, lips, tongue, throat, and ears.
- Change shape, move around, and disappear within hours, only to reappear elsewhere.
- Sometimes join together to form larger raised areas.
- Be accompanied by angioedema, which is swelling in the deeper layers of the skin, often around the eyes, lips, or genitals.
Hives can be acute (lasting less than six weeks) or chronic (lasting more than six weeks). Chronic hives can be particularly frustrating and may have less identifiable triggers.
Diagnosis:
A healthcare professional can usually diagnose hives based on a physical examination and your medical history, including potential exposures to triggers. They may ask about:
- When the hives started and how long they last.
- Possible triggers, such as foods, medications, or environmental exposures.
- Other symptoms you may have.
In some cases, the doctor may recommend:
- Allergy testing: Skin prick tests or blood tests to identify specific allergens.
- Blood tests: To check for underlying medical conditions.
- Skin biopsy: Rarely needed, but may be done to rule out other skin conditions.
- Provocation testing: For physical urticaria, this involves exposing the skin to suspected physical triggers (e.g., applying pressure, ice).
Treatment:
The goal of treatment is to relieve itching and reduce the hives.
- Avoidance of triggers: Identifying and avoiding known triggers is crucial.
- Medications:
- Antihistamines: These are the first-line treatment for hives and work by blocking histamine release. Non-sedating antihistamines are usually preferred for daytime use.
- H2 blockers (histamine H2 receptor antagonists): May be used in combination with H1 antihistamines, particularly for chronic hives.
- Corticosteroids (oral or topical): May be prescribed for severe acute hives to reduce inflammation, but are not typically used long-term due to potential side effects.
- Leukotriene receptor antagonists: Can be helpful in some cases, especially when asthma or allergic rhinitis is also present.
- Omalizumab: An injectable medication that targets IgE antibodies and is used for chronic spontaneous urticaria that doesn’t respond to antihistamines.
- Cyclosporine and other immunosuppressants: May be used for severe chronic urticaria that is resistant to other treatments.
- Cool compresses or showers: Can help soothe itchy skin.
- Loose-fitting clothing: Avoid tight or irritating clothing.
Prevention:
Preventing hives involves identifying and avoiding known triggers. This may include:
- Keeping a food and symptom diary to track potential food allergies.
- Informing healthcare providers about any medication allergies.
- Avoiding known physical triggers if you have physical urticaria.
- Managing stress.
If you experience hives, especially if accompanied by difficulty breathing, swelling of the face or throat, dizziness, or wheezing, seek immediate medical attention as these could be signs of a severe allergic reaction (anaphylaxis). For persistent or chronic hives, schedule an appointment with us so that we can help you identify potential causes and develop an appropriate management plan.
