Hypersensitivity Type I: Immediate

Examples of local (atopic) reactions

Allergic rhinitis

Example of systemic reaction

Anaphylaxis

Is there a genetic predisposition to allergy

YES! (If both parents have allergies, there is an 80% chance the child will have allergies)

Potential allergens

Foods

Meds

Insect bite/sting

Contrast media

Blood

Primary mediator of type I hypersensitivity reaction

IgE

When does the reaction happen in type 1?

The SECOND exposure to the allergen

(1st exposure → IgE antibodies attach to mast cell → 2nd exposure → allergen attaches to IgE that is on the mast cell → HISTAMINE released → reaction occurs)

How can you avoid reaction with blood types?

Double check blood compatibility

• Right pt

• Right type

• Right blood

Clinical Manifestations of Allergic Rhinitis

Nasal Discharge

Sneeze

Pruitis (itch) of upper airway

HA

Sinus pressure

Itchy Watery Eyes

Clinical Manifestations of Anaphylaxis

Dyspnea/SOB → AIRWAY

Wheezles/Crackles

Rash

N/V or Diarrhea

Anxiety 

Feel flush of heat

Angioedema

Cool/clammy skin

Clinical manifestations of EXTREME anaphylactic reaction

Brochospasm with extreme dyspnea & SOB → AIRWAY!!!

Hoarseness and stridor → Narrow AIRWAY

HYPOtension & TACHYcardia

Restless/Confusion

How may the patient in anaphylaxis sound?

Wheeze/Crackles on ausculation

Hoarseness & Stridor (HIGH PITCH) → NARROW AIRWAY

Vital signs in Anaphylaxsis

HYPOtension

TACHYcardia

Due to vasoDILATION and capillary leak

What does the release of histamines cause?

Smooth muscle CONTRACTION (Bronchioles → Bronchoconstriction)

VasoDILATION (Lower BP → Fluid shifts→ angioedema)

Increased Vascular permeability

Edema

BronchoCONSTRICTION

Important teaching for Corticosteroids

TAPER!!! (prevent adrenal insufficiency)

Not for long term (immunosuppression

In PEDS, how should you introduce new foods (potential allergens)

1 at a time

What WBC may be elevated in an allergic response?

Eosinophils (WNL = 1-2%)

Eosinophils in severe seasonal allergic rhinitis

As high as 12%

What does skin testing determine?

Specific allergen (scratch test)

Cause of allergic rhinitis, urticaria (hives), and asthma

Key points of allergy management

IDENTIFICATION

Tx

PREVENT → Avoid when the allergy has bee nidentified

Diphenhydramine Hydrochloride

Benadryl (antihistamine)

MOA of Benadryl

Decrease Edema

Decrease constriction of smooth muscle (respiratory)

Pt teaching for Diphenhydramine Hydrochloride (Benadryl)

May cause DROWSINESS

Prednisone

Corticosteroid

MOA of corticosteroids

Inhibit inflammatory response and decrease mast-cell degradation

Albeuterol

Beta-agonist bronchodilator

MOA of Albeuterol

Ease respiratory distress by causing smooth muscle relaxation

What to monitor with Albuterol (Beta agonist/bronchodilator)

Heart rate

can cause TACHYcardia

Most common clinical manifestations of anaphylaxis

Urticaria (rash/hives)

Angioedema

Respiratory Distress 

1st line tx for anaphylaxis

IM epinephrine

MOA of Epinephrine

Respiratory smooth muscle relaxant (DILATES bronchioles)

CONSTRICTS blood vessels

Improves CO

How often can Epi be repeated?

q 5 - 15 mins

Typical dose of Epi

0.3 - 0.5 mL of 1:1,000 Epinephrine

If the offending agent is in an IV infusion, what should the nurse do?

Stop the IV medication, change the IV TUBING (don’t need a new IV), hand NS

How should O2 be administered?

as ordered via 100% nonrebreather

How should the pt be positioned?

HOB elevated: Fowlers or high-fowlers

Tripod position

S/S of initial reaction that the patient should be educated on

Rash and Itching

Teaching for the patient

Avoid exposure

S/S of initial reaction

Epipen use

Medic Alert Bracelet

Epipen education

How to give

Check expiration date

Keep out of sun

Make sure the vial isn’t cloudy

Educate Family