Friday, 21 August 2020

Acute Emergencies : Anaphylaxis

 

ANAPHYLAXIS

Anaphylaxis means a  severe allergic reaction to an allergen to which an individual has previously been exposed to.

It occurs due to antigen specific cross linking of IgE on surface of tissue mast cells and peripheral basophils.

History Taking

Usually there is a clearly identifiable allergen / precipitant which has caused anaphylaxis.

If the allergen is not identifiable  we have to ask the following points in History :

Any past history of similar allergic reaction

Any known allergies.

Did this reaction occur after eating a particular food ?

Was the patient bitten by an insect eg bee, wasp, ant etc?

Did he wear any new jewelry or used any new cosmetic product ,hair dye etc.

Any latex / rubber allergy?

Any history of allergy in the family?

Investigations

Full blood count including Eosinophils

Skin prick testing

Serum mast cell tryptase : Elevated after anaphylaxis

C1 inhibitor deficiency

Clinical features

Patient develops symptoms within seconds to minutes.

These occur due to development of tissue oedema as a result of release of inflammatory mediators.

The common Signs and Symptoms include :

Difficulty breathing

Facial and tissues swelling

Rash over body

Itching of eyes

Sneezing and conjunctivitis to name a few.

Sometimes if the reaction is severe, it will prove to be life threatening.

Management :

Assessemnt of ABC : Airway , Breathing , Circulation

Administer High Flow Oxygen

Monitor Oxygen Saturations

Establish iv access / cannulation

In case of respiratory distress or wheeze / stridor, give adrenaline /epinephrine  0.5 ml of 1:1000 solution intramuscularly.

This can be repeated in 5 minutes if no improvement.

Administer iv hydrocortisone from 100 mg upto 500 mg depending on the severity of anaphylaxis.

Administer Chlorpheniramine 10 mg iv .

In case of  wheeze / bronchospasm , give nebulization by salbutamol / ipratropium or Clenil .

If patient is hypotensive give iv fluids eg Normal saline 0.9 % 1 litre straight away.

 

 

No comments:

Post a Comment