Anaphylaxis in Infants

Clinical Presentation and Diagnosis

The American Academy of Pediatrics recommends that anaphylaxis is likely when any one of the three criteria is met: acute onset with skin/mucosal involvement plus respiratory compromise or reduced blood pressure, two or more of the following occurring rapidly after allergen exposure, or reduced blood pressure after exposure to a known allergen 1
Anaphylaxis in infants presents with unique symptoms, including skin manifestations, respiratory compromise, cardiovascular symptoms, and gastrointestinal symptoms 1
Behavioral changes specific to infants, hypotonia, and incontinence are also potential signs of anaphylaxis in infants 1

The American Academy of Pediatrics recommends epinephrine as the first-line treatment for anaphylaxis in infants, administered immediately via intramuscular injection in the mid-outer thigh 2, 1, 3
The recommended dose of epinephrine for infants is 0.01 mg/kg of 1:1000 solution 3
For infants weighing >7.5 kg but <15 kg, the 0.15 mg epinephrine auto-injector is recommended despite being a higher dose than calculated 2
Adjunctive treatments, such as H1 antihistamines, H2 antihistamines, bronchodilators, supplemental oxygen, and IV fluids, may be used after epinephrine administration 4, 5

All infants who receive epinephrine should be transported to an emergency facility for observation, with an observation period of 4-6 hours being reasonable for most patients 4, 1
Infants who have experienced anaphylaxis should be sent home with an anaphylaxis emergency action plan, an epinephrine auto-injector, and education for caregivers about anaphylaxis recognition and first-aid treatment 4, 1, 6