What is the Difference Between Type I and Type IV Hypersensitivity?
🆚 Go to Comparative Table 🆚Type I and Type IV hypersensitivity reactions are both immune responses that can cause harm to the host, but they differ in their mechanisms, clinical manifestations, and response times.
Type I Hypersensitivity Reaction
- Mediated by IgE antibodies
- Produces an immediate response after exposure to an antigen
- Involves the sensitization stage and the effect stage
- Common triggers include food products, animal sources, environmental sources, and allergic conditions
- Symptoms include rash, flushing, hives, itching, edema, wheezing, rhinitis, and stomach cramps
Type IV Hypersensitivity Reaction
- Mediated by T cells as a delayed cell-mediated response
- Occurs 48–72 hours after exposure to an antigen
- Subdivided into Type IVa, IVb, IVc, and IVd based on the type of T cell involved
- Triggered by a wide variety of causes, such as contact dermatitis, poison ivy, certain metals, and drugs like antibiotics or anticonvulsants
- Clinical manifestations include contact dermatitis, tuberculin-type hypersensitivity, and granulomatous-type hypersensitivity
In summary, Type I hypersensitivity reactions are mediated by IgE antibodies and produce immediate responses, while Type IV hypersensitivity reactions are mediated by T cells and result in delayed responses. Both types of reactions can cause harm to the host, but they differ in their mechanisms, clinical manifestations, and response times.
Comparative Table: Type I vs Type IV Hypersensitivity
Here is a table comparing Type I and Type IV hypersensitivity reactions:
Feature | Type I Hypersensitivity | Type IV Hypersensitivity |
---|---|---|
Mediated by | IgE antibodies | T cells |
Timeframe | Immediate (minutes) | Delayed (24 to 72 hours after antigen exposure) |
Examples | Allergy, anaphylaxis, atopy | Contact dermatitis, tuberculin-type hypersensitivity, granulomatous-type hypersensitivity |
Mechanism | Involves the production of effector molecules capable of ingesting foreign particles, association with parasite infection | Involves T-cell regulated actions and effector cells, leading to tissue damage mediated by activated macrophages |
Type I hypersensitivity reactions are mediated by IgE antibodies and typically occur immediately after antigen exposure, such as in allergic reactions and anaphylaxis. On the other hand, Type IV hypersensitivity reactions are T-cell mediated, delayed in nature (occurring 24 to 72 hours after antigen exposure), and can involve tissue damage mediated by activated macrophages.
- Immediate vs Delayed Hypersensitivity
- Hypersensitivity vs Autoimmunity
- Type I vs Type II Interferon
- Innate vs Adaptive Immunity
- MHC I vs II
- Inflammation vs Allergy
- Anaphylaxis vs Allergic Reaction
- Type 1 vs 2 Collagen
- Cell Mediated vs Antibody Mediated Immunity
- Allergy vs Intolerance
- IgG vs IgE
- Primary vs Secondary Immune Response
- Blood Types
- Humoral vs Cell Mediated Immunity
- Type 1 vs Type 2 Diabetes Mellitus
- Allergens vs Allergies
- Allergen vs Antigen
- Type I vs Type 2 Citrullinemia
- ITP vs TTP