Anaphylaxis

Anaphylaxis is the Most Severe form of Allergy

What is Anaphylaxis ?

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.

Risk Factor for Anaphylaxis

Following are the risk factors for anaphylaxis:

  • Previous history of anaphylaxis. If you already had anaphylaxis once, then your chance of having anaphylaxis second times increases. Second time reaction may be more severe.
  • Atopy: Atopy is the inherited tendency to develop allergy.
  • Gender: Risk of anaphylaxis is more in male under 15 years of age whereas the risk is more in female of more than 15 years of age.
  • Allergies or asthma. Those who are already had asthma or some form of allergic disorder at increased risk of anaphylaxis.

Causes of Anaphylaxis

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

Diagnosis of Anaphylaxis

Treatment of Anaphylaxis

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 of Anaphylaxis

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

Read in-depth of Anaphylaxis

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Point to be remembered in managing Anaphylaxis

Avoidance of the offending agent is very important. One must know the causative food to which he is allergic. Always check twice while  eating in  restaurants and in social events.

Follow these steps:

  • Know what you’re eating and drinking. Always read the food labels while you eating something.

  • If you have already had a severe reaction/anaphylaxis, wear a medical alert bracelet or necklace that will alert others and you have a food allergy.

  • Have an action plan ready. Always have a action plan of your Anaphylaxis. This action plan will be prepared by your Allergist.

  • Always have your Epinephrine / Adrenaline Autoinjector with you.

  • Do not hesitate to inject intramuscular adrenaline / autonjector even you are in doubt.

  • Always attend hospital even the symptoms get improved after taking adrenaline autoinjector

If your child has allergy/anaphylaxis, you must follow few steps to ensure your child is safe:

  • Always notify key people about the child’s allergy/anaphylaxis. Inform your child care providers, school personnel, parents of your child’s friends and other adults who regularly interact with your child. Tell them that anaphylaxis is a life threatening form of allergy which require urgent intervention to save life of the child.
  • Explain the anaphylaxis symptoms to persons who spend time with the child.
  • Have a written action plan of Anaphylaxis. This plan should include the appropriate management strategies to care the child in emergency case of anaphylaxis. One copy of the plan must be given to school authority.
  • Have your child wear a medical alert bracelet or necklace to display that he/she has Food Allergy.

In-depth reading of Anaphylaxis

What is Anaphylaxis:

Anaphylaxis is a severe, life-threatening allergic reaction. 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.

Mechanism of Anaphylaxis:

Anaphylaxis is a life-threatening syndrome resulting from the sudden release of mast cell- and basophil-derived mediators into the circulation.

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.

Risk factors for Anaphylaxis:

Following are the risk factors for anaphylaxis:

  • Previous history of anaphylaxis. If you already had anaphylaxis once, then your chance of having anaphylaxis second times increases. Second time reaction may be more severe.
  • Atopy: Atopy is the inherited tendency to develop allergy.
  • Gender: Risk of anaphylaxis is more in male under 15 years of age whereas the risk is more in female of more than 15 years of age.
  • Allergies or asthma. Those who are already had asthma or some form of allergic disorder at increased risk of anaphylaxis.

Incidence and prevalence 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:

Food

  • Food can cause anaphylaxis.  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 can cause anaphylaxis.  Less commonly, biting insects.

Medication

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

Blood transfusion

  • Blood transfusion can cause mild allergic reaction to severe form of allergy. 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

  • Allergy reactions to IV dye can occur ranging from mild to moderate reaction to more severe  life-threatening anaphylatic reaction.

Differential diagnosis of Anaphylaxis:

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.

Management of anaphylaxis:

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

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.
  • 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.

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.