Type 1 HSR Flashcards
HSR 1 also known as?
Anaphylactic or Immediate Hypersensitivity reaction
Most important cell goin to be required at the start of Stage 1 in HSR1?
T helper cell, subtype 2
Important cytokine involved in the release of IgE antibody
IL4
Which antibody increases at the time of type 1 HSR?
IgE
Which is the WBC that increases with the action of IL5?
Eosinophils
Which connective tissue has receptors for IgE antibodies?
Mast cells
True/False: At the sensitization stage of HSR1, The patient is asymptomatic.
True.
Most common antigen, in India, responsible for immune cell activation in HSR1 in Bronchial Asthma. How about in western countries?
House dust in India and Pollen in western countries.
Inflammatory chemicals responsible for the clinical symptoms in HSR1.
Histamine, Prostaglandins, and Leukotrienes
In the second stage, how does the mast cell get activated?
When the antigen forms and Ag-Ab complex on the surface of mast cells
What are the two inflammatory chemicals release by mast cells upon activation?
Histamine & Arachidonic acid (gives rise to prostaglandins and Leukotrienes)
Enzyme responsible for production of the two chemicals formed by Arachidonic acid
1) COX enzyme for AA ——- Prostaglandins
2) 5-LOX enzyme for AA——- Leukotrienes
What symptoms are produced by Histamine and Prostaglandins in HSR1?
Vasodilation and increased mucous secretion ——- Cough
What symptoms are produced due to Histamine and leukotrienes?
Bronchospasm —- dyspnea
How does penicillin cause HSR1?
Penicillin administration ———— Anaphylactic shock ————— inc. BP, laryngeal edema, dyspnea
Laryngeal edema - chokes the patient ——- death
How do you manage a px. with anaphylactic shock?
- Give Adrenaline 1:1000, 0.5ml, IM
Drug that may cause Type 1 HSR
Some antibiotics, especially Penicillin
Leukotriene receptor antagonist used for Asthma.
Montelukast
Drug that inhibits the formation of Leukotrienes . Also, whats the side effect due to which it’s not commonly used?
A 5 LOX inhibitor: Ziluton. S/E: Liver toxicity
Drugs that inhibits the formation of Arachidonic acid in bronchial asthma.
Phospholipase A2 inhibitor: Steroids
Drugs that reduces the activity of mast cells (mast cell stabilizers), used for bronchial asthma.
1) Sodium cromoglycate
2) Olopatadine
Drug that’s a mast cell stabilizer and also a anti-histamine, used for bronchial asthma, as well as spring catarrh (allergic conjunctivitis)
Olopatadine
How do you diagnose atopic dermatitis?
- Clinically diagnosed.
- White scratch appears on skin when scratched with a blunt object. Known as “white dermographism”.
Casoni’s test is done for detecting HSR1 caused by what organism?
Eccinococcus granulosus (dog tapeworm)
Primary and secondary hosts in E. granulosus? Human?
Primary: canine
Secondary: Sheep
Human: accidental host
Radiographic findings of E. granulosus
Water lily sign (cysts, most commonly present in the liver)
Other sites of cyst: Lungs > Spleen
Management of E. granulosus
- Anti-helminthic drugs (Albendazole)
- PAIR (Percutaneous Aspiration and Infusion of Reagent)
Reagent used: 95% Ethanol
Hypertonic saline (20% saline)
Examples of conditions having HSR1
A —- Allergies,Atopy
B —- Bronchial Asthma, Bee (insect) sting
C —- Casoni’s Test
D —- Drugs (antibiotics, especially penicillin)
Classification system used to classify HSR.
Gel Coombs Classification
HSR 1 - Free antigen, Fixed antibody
HSR2 - Free antibody, Fixed antigen
HSR 3 - Free antigen and antibody
HSR 4 - Not antibody mediated, but CELL MEDIATED HSR.
Antibody mediated: HSR1, HSR2, HSR3
Cell mediated: HSR4
