Urticaria, commonly known as hives, is a skin condition characterized by itchy, raised welts on the skin.
Urticaria is essentially a skin reaction that manifests as itchy welts, sometimes described as wheals. These welts can vary in size and shape, and they often appear suddenly. The underlying cause of urticaria can be diverse, ranging from allergic reactions to infections, stress, or even physical stimuli. Chronic urticaria is defined as hives that persist for more than six weeks and recur frequently over a period of months or even years.
Key Characteristics of Urticaria:
- Welts: The hallmark of urticaria is the appearance of raised, swollen patches on the skin, known as wheals.
- Itchiness: Intense itching is a common symptom, though sometimes a burning or stinging sensation can be present.
- Appearance: Hives can vary in size and shape, and they may appear red or skin-colored. They can also blanch (turn white) when pressed.
- Transient Nature: Individual hives typically resolve within 24 hours, but new ones can appear as older ones fade.
- Angioedema: Urticaria can sometimes be accompanied by angioedema, which is swelling in deeper layers of the skin, often affecting the face, lips, tongue, or throat. Angioedema can be dangerous if it affects breathing.
Types of Urticaria:
- Acute Urticaria: This type lasts less than six weeks and is often triggered by an allergic reaction to food or medication. Infections can also cause acute urticaria.
- Chronic Urticaria: Hives that persist for more than six weeks are classified as chronic. The cause is often difficult to identify and may involve autoimmune factors.
- Physical Urticaria: This type is triggered by physical stimuli such as pressure, cold, heat, sunlight, vibration, or exercise.
Causes of Urticaria:
Urticaria can be triggered by a variety of factors:
- Allergies: Foods (e.g., nuts, shellfish), medications (e.g., antibiotics, NSAIDs), insect stings, and latex are common allergens.
- Infections: Viral, bacterial, or fungal infections can sometimes trigger hives.
- Physical Stimuli: Pressure, cold, heat, sunlight, and vibration are common physical triggers.
- Medical Conditions: Autoimmune diseases, thyroid disorders, and some cancers can be associated with urticaria.
- Stress: Emotional stress can sometimes worsen or trigger urticaria.
Treatment of Urticaria:
Treatment for urticaria focuses on relieving symptoms and identifying and avoiding triggers:
- Antihistamines: These medications block histamine, a chemical released during an allergic reaction that causes itching and swelling.
- Corticosteroids: These medications can reduce inflammation and are sometimes used for severe cases of urticaria.
- Epinephrine: For severe allergic reactions that cause breathing difficulties (anaphylaxis), an epinephrine injection (EpiPen) may be necessary.
- Other Medications: In cases of chronic urticaria that don't respond to antihistamines, other medications such as omalizumab (Xolair) may be prescribed.
- Trigger Avoidance: Identifying and avoiding triggers is crucial for preventing future outbreaks of urticaria.
In summary, urticaria is a common skin condition characterized by itchy welts that can be caused by various triggers, ranging from allergies to physical stimuli. Treatment typically involves antihistamines to relieve symptoms and identifying and avoiding potential triggers.
