Anaphylaxis

Anaphylaxis is the Most Severe form of Allergy and can be life threatening.

What is Anaphylaxis or Severe Allergic reaction ?

Anaphylaxis/ Severe allergic reaction is a severe, life-threatening allergic reaction. Anaphylaxis is the severe form of allergy. It require urgent management.

The term anaphylaxis was first proposed by physiologist Charles Robert Richet  and Paul Portier in the year 1902. “Ana” means “against” and “phylaxis” meaning “protection”.

Urgent attention is needed to save the life of the individual who is suffering from anaphylaxis. 

Symptoms of Anaphylaxis

Generalized urticaria and angioedema are the most common manifestations of anaphylaxis

Following are the symptoms of anaphylaxis

Throat:  Itching, tightness in the throat, hoarseness of voice

Skin: Itching, hives/ Urticaria, redness, swelling, angioedema

GIT:  Vomiting, diarrhea, cramp in the abdomen

Lung:  Respiratory difficulty/shortness of breath, cough, wheeze

Heart:  Weak pulse, dizziness, reduced BP

Only a few symptoms may be present. Severity of symptoms can change quickly.

Incidence of Anaphylaxis

Exact incidence of anaphylaxis is unknown. Anaphylaxis is often underreported, under diagnosed. The lifetime prevalence may be as high as 2 percent.

Causes of Anaphylaxis

Atigen/ allergen that can lead to anaphylaxis include but not limited to

Food

These include peanuts, tree nuts,  fish, shellfish, cow’s milk, soy products, eggs, wheat.

Insect stings

Stinging insects like honeybees, yellow jackets, fire ants, hornets and paper wasps

Medication

Medicines like β-lactams like penicillin,  Nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin and ibuprofen Biologic modifier.

Blood transfusion

 Anaphylaxis can occur in approx 1 in 20,000 to 1 in 50,000 transfusions.

Natural Rubber Latex

Latex is a common component of many medical and dental supplies including gloves, intravenous tubing, syringes, catheters. Latex is also used in condoms.

Radiocontrast media

Treatment

Anaphylaxis is a medical emergency. It can be fatal if left untreated.

If someone has symptoms of anaphylaxis, you should:

  • Use an adrenaline/epinephrine auto-injector. Give another adrenaline injection after 5-15 minutes if the symptoms don’t improve and a second auto-injector is available
  • Call emergency number for an ambulance immediately
  • Remove any trigger if possible – for example, carefully remove any wasp or bee sting stuck in the skin
  • Lie the person down flat. The left lateral position is recommended for patients who are pregnant.

Dose of Adrenaline/Epinephrine

Dose of Adrenaline / Epinephrine

 10-20 kg (~1-5yrs) – 0.15mg (green labelled on autoinjector)

>20kg (~>5yrs) – 0.3mg (yellow labelled on autoinjector)

Pregnant woman- 0.3mg (yellow labelled on autoinjector)

If do not have autoinjector or in hospital settings

Give INTRAMUSCULAR (IM) injection of Adrenaline/ Epinephrine as follows:

  • 1:1000 solution of Adrenaline in IM into outer aspect of mid-thigh in right site.
  • 0.01mg per kg up to maximum of 0.5mg per dose can be used.
  • Repeat every 5 minutes as needed.

Prevention of Anaphylaxis

It is extremely crucial to alert all the time and follow few preventive measures to reduce the risk of anaphylaxis.

The following can help:

  • Identify any triggers – Attend any allergy clinic to know what the substances you are allergic to. This will help you to plan your management strategy.
  • Avoid triggers whenever possible – Once you identified the possible factors for triggering anaphylaxis then you can take avoidance measures to reduce the risk. For example if you are allergic to certain food then you have to shop very carefully.
  • Carry your adrenaline auto-injector at all times with you– use it in emergency situation.

Differential Diagnosis

A variety of condition may mimic sign symptoms of Anaphylaxis. Few differential diagnosis of Anaphylaxis include

  • Vasovagal syncope
  • Acute exaggeration of Bronchial Asthma
  • Panic attack
  • Cardiovascular events like Myocardial ischemia
  • Systemic mastocytosis
  • Neurological events like stroke, seizure episode
  • Basophilic leukemia
  • Shock due to any cause like hypovolemia, sepsis etc
  • Hereditary angioedema

Also read

FAQs Frequently asked questions on Anaphylaxis

Symptoms of anaphylaxis are diverse

Causes of Anaphylaxis

Treatment of Anaphylaxis