Urticaria

Definition

Urticaria, commonly known as hives, is a skin condition characterized by raised, itchy welts that can vary in size and shape. It is caused by an allergic reaction or other triggers that lead to the release of histamine and other chemicals in the skin, disrupting normal immune function and resulting in inflammation.

5 Must Know Facts For Your Next Test

1. Urticaria can be acute, lasting less than six weeks, or chronic, lasting for six weeks or longer.
2. Common triggers for urticaria include certain foods, medications, insect stings, and environmental factors like heat or pressure.
3. The itchy welts associated with urticaria are often temporary and can appear and disappear within hours.
4. Treatment for urticaria typically involves antihistamines to reduce itching and inflammation.
5. In severe cases, especially if accompanied by other symptoms like swelling of the throat, urticaria may indicate anaphylaxis and requires immediate medical attention.

Review Questions

• How do allergens contribute to the development of urticaria?
  • Allergens trigger an immune response in susceptible individuals that leads to the release of histamine from mast cells. This histamine release causes blood vessels to leak, resulting in the characteristic raised welts and itching associated with urticaria. Understanding this connection highlights the importance of identifying specific allergens to prevent outbreaks.
• Discuss the differences between acute and chronic urticaria and their implications for treatment.
  • Acute urticaria lasts less than six weeks and is often linked to identifiable triggers like food or medication. In contrast, chronic urticaria persists for six weeks or longer without a clear cause. The treatment approach may differ; acute cases often respond well to antihistamines, while chronic cases may require a more thorough investigation and long-term management strategies.
• Evaluate the role of histamine in urticaria and discuss potential treatments that target this pathway.
  • Histamine plays a central role in the development of urticaria by causing vasodilation and increased permeability of blood vessels, leading to swelling and itchiness. Treatments like antihistamines directly block histamine receptors, reducing these symptoms. Understanding this mechanism allows for targeted therapeutic approaches, such as using newer antihistamines that provide longer-lasting relief or exploring alternative therapies that modulate immune responses.

Related terms

Histamine: A chemical released by the immune system during an allergic reaction, causing inflammation, itching, and other symptoms associated with urticaria.

Allergen: A substance that can trigger an allergic reaction in susceptible individuals, potentially leading to conditions like urticaria.

Anaphylaxis: A severe, potentially life-threatening allergic reaction that can occur rapidly and may include symptoms such as difficulty breathing, swelling, and widespread hives.