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Flashcards in Hypersensitivity Deck (10):
1

A 22 year old woman presents with an intermittently itchy and desquamating skin rash on her abdomen which is unresponsive to antihistamines.

Contact hypersensitivity: typical rash, in area where belt rubs.

2

A 35 year old woman presents with a two day history of a red itchy skin rash which started soon after her first scuba-diving lesson. She is otherwise well.

Acute urticaria: suggestive rash, after ?latex.

3

A&E, tongue swelling and acute respiratory tract obstruction. Blood pressure stable, Normal breath sounds. Medication includes cyclosporine, azathioprine, captopril and nifedipine.

Angioedema: no generalised allergic reaction. Most is drug-induced, mostly ACEi like captopril.

4

Anaphylaxis Tx

500 micrograms adrenaline (0.5ml).
Under 12yo: 300 mcg
Under 6yo: 150 mcg

5

Angioedema Tx (without anaphylaxis)

IV or IM antihistamines

6

Non-autoimmune - Re-exposure, IgG, mast cells.

Type I hypersensitivity - allergy.

7

Ab (IgG/IgM) to self

Type II hypersensitivity

8

IgG/IgM immune complexes

Type III hypersensitivity

9

Delayed response, T cell-mediated reaction

Type IV hypersensitivity

10

Anaphylaxis

Mast cell degranulation:
- IgE mediated: peanuts, stings, penicillin, latex;
- non-IgE: NSAIDs, opioids, contrast, exercise.