Pediatric Pearl – Anaphylaxis

Posted on by Nick Mota

ANAPHYLAXIS

By: Hima Khamar, PGY3

4-year-old female presents to ED with parents due to 1 week of cough, fever, congestion, irritability, and decreased PO intake. CXR shows RLL pneumonia, patient is started on Ceftriaxone. 5 mins after the initiation of Ceftriaxone infusion, patient begins to complain of itchy scalp, starts coughing uncontrollably (much worse than throughout her entire ED stay), and some urticaria is noted on her abdomen. Per mom, patient has never been on antibiotics, but has allergies to many fruits and foods. THIS WAS A REAL PATIENT OF MINE*

GOALS:

-Correctly identify and diagnose anaphylaxis
-Don’t be afraid to give epinephrine and give it in a timely manner
-Monitor frequently and if not improving, don’t be afraid to take the airway
-Provide epinephrine auto-injector to go home with, if stable for discharge
-Give parents and patient (if old enough) education of anaphylaxis and how to use autoinjector

HISTORY AND PHYSICAL

HISTORY:
-What are the manifestations
-What time did attack(s) start
-How long did episode(s) last
-Treatments administered
-Potential causes
-Previous attacks, including severity
-Atopic status, particularly presence of asthma

PHYSICAL:
-Vital Signs
-Skin: Hives, pruritis, or flushing
-Edema: Mucosal tissue, lips, tongue, uvula
-Airway: Stridor, hoarseness, cough, trouble swallowing
-Breathing: Cough, dyspnea, wheezing, retractions, hypoxemia
-Circulation: Hypotension, tachycardia, delayed capillary refill, poor perfusion
-Neurologic: Change in mental status, syncope, sense of impending doom
-Gastrointestinal: Persistent vomiting, abdominal pain, diarrhea

Anaphylaxis Criteria

Criteria 1:

  • Acute onset of an illness with involvement of the skin, mucosal tissue, or both (e.g., generalized hives, pruritis or flushing, swollen lip-tongue-uvula)
  • AND AT LEAST ONE OF THE FOLLOWING:
    • Respiratory compromise, Reduced BP or associated symptoms of end-organ dysfunction, Persistent GI Symptoms, Significant abdominal pain and/or significant vomiting

Criteria 2:

  • Two or more of the following that occur rapidly after exposure to a LIKELY ALLERGEN
    • Involvement of the skin-mucosal tissue, Respiratory compromise, Reduced BP or associated symptoms, Persistent gastrointestinal symptoms

Criteria 3:

  • Reduced BP after exposure to KNOWN ALLERGEN

Anaphylaxis Caveats

  • While the majority of anaphylaxis cases involve skin symptoms, 10% of patients do not have hives or other skin manifestations; these patients often have the most severe symptoms.
  • Isolated skin findings alone (generalized hives) should not automatically be defined as anaphylaxis.
  • In a patient with exposure to a known allergen that has previously caused anaphylaxis that presented with hives alone, threshold should be low for the diagnosis of anaphylaxis.
  • The above signs/symptoms obviously can be due to non-allergic causes.
  • The absence of exposure to a known allergen should never preclude the diagnosis of anaphylaxis.
  • Patients on beta blockers should get glucagon if the first dose of epinephrine is ineffective.

VITAL SIGNS

(Very important in helping diagnose, so here is a quick review)

AGE GROUP RESP RATE HEART RATE SYSTOLIC BP DIASTOLIC BP WEIGHT (KG)
New born 30-50 120-160 50-70 30-60 2-3
Infant (<1 yr) 20-30 80-140 70-100 53-66 4-10
Toddler (1-3) 20-30 80-130 80-110 53-66 10-14
Preschooler (3-5) 20-30 80-120 80-110 55-69 14-18
School Age (6-12) 20-30 70-110 80-120 57-71 20-42
Adolescent (>13) 12-20 55-105 110-120 66-80 >50

*Every degree Celsius rise in temperature should show a 10% rise in HR

MEDICATIONS

Albuterol

  • <5 kg – 5mg/hr cont
  • 5-10 kg – 5mg/hr cont
  • 10-20 kg – 25mg/hr cont
  • >20 kg – 15mg/hr cont

Steroids

  • Methyprednisolone IV 2mg/kg (max 60mg)
  • Prednisone PO 2mg/kg (max 60mg)
  • Dexamethasone PO 0.3-0.6mg/kg (max 12mg)

Racemic Epi (stridor)

  • <5 kg: 25 mL
  • 5-10 kg: 5 mL

 Antihistamines

  • Diphenhydramine IV/PO 1mg/kg (max 50mg)
  • Ranitidine IV 1mg/kg (max 50mg) or PO 4mg/kg (max 150mg)
  • Cetirizine PO <24mths 2.5mg/day, 2-5yrs 2.5-5mg/day, >6yrs 5-10mg/day

Vasopressors

  • Epinephrine 01-0.1 mcg/kg/min

Glucagon (if on beta blockers) à 20-30 mcg/kg (max 1mg) over 5 mins

Anaphylaxis Red Flags

-History of biphasic or severe reactions
-Progression of / or persistent symptoms
-History of severe asthma
-1 ICU admission and/or 3 in-pt admissions/year
-Current asthma flare
-Hypotension during ED stay
-Requires >1 Epinephrine dose
-Requires fluid bolus
-Upper airway obstruction i.e. stridor

Discharge Criteria

  • Complete clinical resolution of all serious symptoms (rash may persist)
  • If epinephrine was administered, observe 4 hours from time of epinephrine administration
  • Parental comfort with discharge with good access to ED if symptoms recur
  • Epinephrine auto-injector physically available to family
  • Counseling regarding allergen avoidance
  • Allergist referral