ANAPHYLAXIS

ANAPHYLAXIS

The first documented case of anaphylaxis was in 2641 B.C., when Pharaoh Menes of Egypt died from a Wasp sting.  While the first fatal reaction to peanuts was described by a Canadian researcher Dr Evans in 1988.

Allergy to venom from wasp stings can cause anaphylaxis as can allergy to latex and drugs such as penicillin and aspirin. Bee sting allergy is less common in the UK.

ANAPHYLAXIS

The most common cause of anaphylaxis in the community is from eating a food to which you are allergic such as nuts, peanuts, eggs, mammalian milk, soya, wheat, fish and shellfish.  These 8 foods account for 90% of cases of food induced anaphylaxis.  Peanuts and tree nuts (such as Brazil nuts, Hazelnuts, Almonds and Walnuts) are the foods most likely to provoke a reaction.

ANAPHYLAXIS

Some people may develop anaphylaxis after eating certain foods such as celery, shrimps, wheat, apple, hazelnut, squid and chicken and then exercising shortly after ingesting the food – triggering Exercise Induced Anaphylaxis.

SYSTEMIC ANAPHYLAXIS

* Most extreme over-reaction of immune system * Caused by allergens which reach bloodstream

* Venomous insect stings * IV and IM drugs * PO drugs (rapid absorption and high

bioavailability)

Anaphylaxis- IgE-mediated

Antibiotics and other medications

Penicillins, β-lactams, tetracyclines, sulfas, vaccines, immunotherapy

Foreign proteins

Latex, hymenoptera venoms, heterologous sera,

protamine, Foods

Shellfish, peanuts, and tree nuts Exercise induced

SYSTEMIC ANAPHYLAXIS

* Mechanism is widespread activation of mast cells throughout body resulting in * Vascular permeability (circulatory collapse /

anaphylactic shock) * Constriction of smooth muscles

* Death by constriction of airways and swelling of epiglottis

ANAPHYLAXIS

Signs within 5 to 30 min (very rarely hours) Recurrent (biphasic) anaphylaxis – occurs 8-10h after the

initial attack Persistent anaphylaxis – can last for up to 32h

SIGNS AND SYMPTOMS OF

SYSTEMIC ANAPHYLAXIS

Signs/Symptoms :

* Skin and soft tissue* Flushing, pruritis, urticaria and angioedema

* Cardiovascular : * Syncope, tachycardia or no pulse, hypotension, cardiac arrhythmias

* Nervous * Apprehension, convulsions , headache, unconsciousness

* Gastrointestinal * Vomiting, diarrhea, abdominal cramps, nausea,

* Respiratory * Wheezing, dyspnoe, bronchospasm

Anaphylaxis

Skin signs:

- erythema, urticaria, pruritis,

Anaphylaxis Skin signs:

- pruritis, angioedema

ANAPHYLAXIS The most common symptoms were urticaria and

angioedema, occurring in 88% of patients. The next most common manifestations were respiratory symptoms, such as upper airway edema, dyspnoe and wheezing. Cardiovascular symptoms of dizziness, syncope, and hypotension, were less common, but it is important to remember that cardiovascular collapse may occur abruptly, without the prior development of skin or respiratory manifestations.

Other symptoms of rhinitis, headache, substernal pain, and pruritus without rash were less commonly observed.

Most Common Clinical Manifestations of Anaphylaxis

Symptom… How often? Urticaria /Angioedema 88% Upper airway oedema 56% Dyspnoe / bronchospasm 50% Flushing 51% Cardiovascular collapse “Anaphylactic shock” 30% GI 30%

ANAPHYLAXIS TREATMENT

Prevention- avoid the allergen People with asthma and/or allergy have the

risk of anaphylaxis, especially those with un-controlled asthma and/or severe allergy risk. These people should consult to an allergy specialist. When the anaphylaxis trigger has been identified by allergy testing, you must avoid the allergen very carefully.

TREATMENT OF SYSTEMIC ANAPHYLAXIS

* Epinephrine is drug of choice* Sympathicomimetic drug acting on

* Alpha receptors of vascular endothelium * Beta receptors of bronchial smooth muscles

* Administered by I.M. injection into antero - lateral thigh * Do not inject into buttock * Do not inject I.V.

* Cerebral hemorrhage * Epinephrine Auto-Injector (EpiPen)

* Adult (0.3 mg) and pediatric (0.15)

How to Give Epinephrine?

Howto Give Epinephrine?

In the muscle….

Which Muscle?

LateralThigh

How to Give Epinephrine?

EpiPen/EpiPen Jr: Directions for Use

EpiPen/EpiPen Jr: Directions for Use

EpiPen/EpiPen Jr: Directions for Use

Use of Epi Pen….

No contraindications in anaphylaxis !!!

Failure or delay associated with fatalities

I. M. may produce more rapid, higher peak levels vs S. C.

Must be available at all times

ADMINISTRATION OFintramuscular ADRENALINE

Intramuscular injection of epinephrine intothe tigh – more effective than injection intothe arm or subcutaneous administration

When to Repeat Epinephrine?

• Practice Parameter Update - US – Repeat every 5 minutes as needed to control

symptoms and blood pressure – Some guidelines suggest liberalizing the

frequency if deemed necessary – no absolute contraindication for epinephrine

• UK Consensus Panel on emergency Guidelines and

International consensus guidelines for emergency

cardiovascular care – May judiciously be repeated as often as every 5

minutes

Who Should Get Epinephrine?

Everyone with rapid progression of symptoms Laryngeal edema Bronchospasm Severe GI symptoms Hypotension Highest fatality rates when epinephrine is

delayed Age is not a limiting factor

Anaphylaxis Treatment –First Line

ESTABLISH AIRWAY and supplemental O2

• I.V. fluids

• Pulmonary symptoms: Albuterol by

nebulization or MDI

• Deterioration of pulmonary symptoms :

Racemic epinephrine by nebulization;

Consider intubation or tracheostomy

After The Epi –Second Line Therapy For Everyone

Antihistamines: H1 + H2 blockers Diphenhydramine 25-50 mg IV/IM/PO

1 mg/kg PO/ IM/ IV (kids) Ranitidine •50 mg IV…….. 4 mg/kg PO

up to 300 mg

1.5 mg/kg IM/IV up to 50 mg (kids)

What About Non-Sedating H-1 blockers? Cetirazine (Zyrtec) 10 mg po q day Loratidine (Claritin) 10 mg po q day Desloratadine (Clarinex) 5 mg po q day Fexofenadine (Allegra)180 mg po q day Only available in oral form, long record

of efficacy with urticaria

Other Second Line Considerations

Inhaled beta-agonists - if wheezing Corticosteroids

– 1-2 mg/kg prednisone PO

– 1-2 mg/kg methylpredisolone IV (max 250 mg)

Not helpful acutely ? Prevent recurrent anaphylaxis Glucagon ( if beta blocked) 1-5 mg slow IV,

1-5 ug/min

Treatment of Anaphylaxis… Observe for a minimum 8-12 hours Rebound or persitant symptoms

Repeat epinephrine, repeat antihistamine ± H2

blocker

This is a simple instruction of injecting EpiPen:

Pull the seal cover.

Put the black tip on your upper thigh (no need to undress

the patient, unless the fabrics is too thick).

Strongly press the EpiPen into your thigh until you feel the

injection done.

Hold the EpiPen for 10 seconds.

Release the EpiPen while slowly massage the injected

area.

Call for medical help/ambulance.

If the symptoms have not reduced after 30 minutes while

you are waiting for medical help, give the second injection.

Anaphylaxis Fatalities Estimated 500–1000 deaths annually 1% risk Risk factors:

Failure to administer epinephrine immediately Peanut, Soy & tree nut allergy (foods in general)Beta blocker, ACEI therapyAsthmaCardiac diseaseRapid IV allergenAtopic dermatitis (eczema)

Miller RL. Epidemiology of anaphylaxis. Presented at: Anaphylaxis: Safely Managing Your Patients at Risk for Severe Allergic Reactions. Postgraduate Institute for Medicine; October 8, 1999; Washington, DC.Bocher BS. Anaphylaxis. N Engl J Med 1991:324:1785–1790

Food-induced Anaphylaxis: Incidence

35%–55% of anaphylaxis is caused by food allergy

6%–8% of children have food allergy

1%–2% of adults have food allergy

Incidence is increasing

Accidental food exposures are common and unpredictable

Kemp SF, et al. Anaphylaxis. A review of 266 cases. Arch Intern Med 1995; 155:1749–54.

Pumphrey RSH, et al. The clinical spectrum of anaphylaxis in northwest England. Clin Exp Allergy 1996; 26:1364–1370.

Bock SA. Prospective appraisal of complaints of adverse reactions to foods in children

during the first 3 years of life. Pediatrics 1987;79:683–688.

Food-induced Anaphylaxis: Common Symptoms

Oropharynx: Oral pruritus, swelling of lips and tongue,

throat tightening

GI: Crampy abdominal pain, nausea, vomiting, diarrhea

Cutaneous: Urticaria, angioedema

Respiratory: Shortness of breath, stridor, cough, wheezing

Food-induced Anaphylaxis: Fatal Reactions

Fatal reactions are on the rise

~150 deaths per year ( in US )

Usually caused by a known allergy

Patients at risk:

Peanut and tree nut allergy

Asthma

Prior anaphylaxis

Failure to treat promptly epinephrine

Many cases exhibit biphasic reactionAnaphylaxis Committee, AAAAI. Anaphylaxis. Teaching Slides. 2000.

Venom-induced Anaphylaxis: Incidence

0.5%–5% (13 million) Americans are

sensitive to one or more insect venoms Incidence is underestimated Incidence increasing due Incidence rising due to more outdoor activities At least 40–100 deaths per year

Venom-induced Anaphylaxis: Common Culprits

Hymenoptera Bees Wasps Hornets

Hymenoptera

Venom-induced Reactions: Common Symptoms

Normal: Local pain, erythema, mild swelling Large local: Extended swelling, erythema Anaphylaxis: Usual onset within 15–20

minutes Cutaneous: urticaria, flushing, angioedema Respiratory: dyspnoe, stridor Cardiovascular: hypotension, dizziness, loss of

consciousness 30%–60% of patients will experience a

systemic reaction with subsequent stings

Venom-induced Anaphylaxis: Prevention

Risk Management

Keep EpiPen or EpiPen Jr on hand at all times

Educate and train on EpiPen use

Develop emergency action plan

Wear a MedicAlert braceletConsult an allergist to determine need for venom immunotherapy

Venom-induced Anaphylaxis: Immunotherapy

Medical criteriaVenom immunotherapy is medically

indicated in any adult with a history of a systemic reaction to an insect sting, and in children who have had life-threatening sting reactions.

Positive venom skin test & sIgE 97% effective Can be discontinued in most after 3–5 years;

Exercise-Induced Anaphylaxis

First reported in 1979 Mechanism of action is unclear Predisposing factors:

ASA , Food, including: shell fish, cheese, dense

fruits, snails. Triggered by almost any physical

exertion Most common in very athletic children

Exercise-Induced Anaphylaxis

Four PhasesProdromal phase is characterized by fatigue,

warmth, pruritus, and cutaneous erythema The early phase: urticarial eruption that

progresses from giant hives may include angioedema of the face, palms, and soles.

Fully established phase: hypotension, syncope, loss of consciousness, choking, stridor, nausea, and vomiting ( 30 minutes to 4 hours.)

Late or postexertional phase, Prolonged urticaria and headache persisting for 24-74 hours.

NON-IgE ANAPHYLAXIS

Drugs Opiates NSAIDs ACE inhibitors

Foods Strawberries Fish e.g. Tuna (Scrombotoxin)

Diagnosing Anaphylaxis

Based on clinical presentation, exposure

Cutaneous, respiratory symptoms most

common

Some cases may be difficult to diagnose

Vasovagal syncope

Systemic mastocytosis

Diagnosing Anaphylaxis

Careful history to identify possible causes

Can be confirmed by serum tryptase

Specific for mast cell degranulation

Remains elevated for up to 6-12 hours

Serum histamine - rises w/in 5 minutes, returns to baseline after 30-60 minutes

Other labs to rule out other diagnoses

Refer to allergist for specific testing

Diagnosing Anaphylaxis

Skin tests/RASTFoodsInsect venomsDrugs

Challenge testsFoodsNSAIDsExercise

Allergists can identify specific causes by:

Anaphylaxis summary…

Signs and Symptoms of Anaphylaxis: Urticaria, itching, hives Rash Rhinitis Bronchospasm Laryngeal Edema Syncope Cardiac Arrest

Treatment: Basic Life Support:

○ Airway○ Breathing○ Circulation

Epinephrine 0.3-0.5 ml of 1:1000 IM Repeat of no response

Oxygen Diphenhydramine

(antihistamine) 50ml IM Corticosteroids Intubation or cricothyrotomy

Can I Predict Severe Anaphylaxis?

Risk Factors Male Consistent antigen administration Shorter time elapsed since last reaction < 1 year Asthma

Meet M. J.

A 13 y/o girl with a bee sting to hand one hour ago

Symptoms: swelling, erythema and pain Treatment and advice?

Treatment and Advice

Clean area, ice for comfort Remove stinger Anti-histamines ? Topical intermediate potency

corticosteroid cream (triamciniline 0.1%) ? Systemic steroids Education/Plan Referral to allergist EpiPen