Poison ivy

Definition

Poison ivy is a plant that produces urushiol, an oily resin causing allergic reactions in most people. Contact with urushiol can lead to a rash characterized by itching, swelling, and redness.

5 Must Know Facts For Your Next Test

1. The immune response to poison ivy is primarily mediated by T cells recognizing urushiol-modified skin proteins.
2. Urushiol acts as a hapten, binding to skin proteins and forming complexes that trigger an adaptive immune response.
3. CD8+ T cells play a crucial role in the inflammatory response seen in poison ivy exposure.
4. The severity of the reaction can vary based on individual sensitivity and amount of exposure.
5. Previous exposure to poison ivy can sensitize the immune system, leading to more severe reactions upon subsequent exposures.

Review Questions

• What component of poison ivy causes allergic reactions?
• How does urushiol function as a hapten in the immune response?
• Which type of T cell is primarily involved in the reaction to poison ivy?

Related terms

Hapten: A small molecule that elicits an immune response only when attached to a large carrier such as a protein.

CD8+ T Cells: A subtype of T cells that play a critical role in killing infected or cancerous cells.

Allergic Contact Dermatitis: An inflammatory skin condition caused by contact with an allergen, such as urushiol from poison ivy.