contact hypersensitivity
Quick Summary
Contact hypersensitivity is a type IV, or delayed, hypersensitivity reaction. This means it's a cell-mediated immune response, primarily involving T cells rather than antibodies.12
The pathology begins when a sensitizing chemical, such as from poison ivy or certain metals, contacts the skin. This chemical alters body proteins, making them appear foreign to the immune system. These altered proteins migrate to lymph nodes, stimulating T cells to multiply. Upon re-exposure to the chemical, these T cells return to the site of contact, triggering inflammation and leading to contact dermatitis. Symptoms typically appear 18 to 24 hours after exposure. Treatment involves corticosteroids and avoiding the sensitizing agent.12
- immune system disorder - Contact hypersensitivity and dermatitis
- immune system disorder - Tuberculin-type hypersensitivity
- immune system disorder - Sensitization, activation, and effector phases
- immune system disorder - Typical type I allergens
- immune system disorder - Treatment of type I allergic responses
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