Anaphylaxis Management in Alpha-Gal Syndrome

Indications for Epinephrine

The American Academy of Otolaryngology-Head and Neck Surgery recommends epinephrine administration immediately for any systemic symptoms of alpha-gal syndrome, including urticaria with respiratory distress, hypotension, angioedema, or anaphylaxis, with no absolute contraindications to its use in life-threatening allergic reactions 1, 2
Cardiovascular involvement, such as hypotension, cardiovascular collapse, or signs of shock, requires immediate epinephrine administration 1, 2
Respiratory symptoms, including bronchospasm, wheezing, chest tightness, shortness of breath, or respiratory distress, necessitate epinephrine use 1, 2
Angioedema, particularly involving the face, lips, tongue, or throat, is an indication for epinephrine administration 1, 2
Multisystem involvement, such as urticaria combined with respiratory or cardiovascular symptoms, requires epinephrine treatment 1, 2

For adults and children ≥30 kg, the recommended dose is 0.3-0.5 mg (0.3-0.5 mL of 1:1000 solution) IM into the anterolateral thigh (vastus lateralis) 1
For children <30 kg, the dose is 0.01 mg/kg (0.01 mL/kg of 1:1000 solution), with a maximum of 0.3 mg IM 1
Epinephrine should be repeated every 5-15 minutes if symptoms persist or worsen 1, 2

The American Academy of Otolaryngology-Head and Neck Surgery advises that epinephrine should be used early when treating systemic reactions, as it is the only effective first-line treatment 1, 2
Most severe reactions occur within 30 minutes of symptom onset, but alpha-gal reactions characteristically occur 3-5 hours after exposure 2, 3
Antihistamines and glucocorticoids should never delay epinephrine administration and do not prevent biphasic reactions 1

All patients with alpha-gal syndrome who have experienced systemic symptoms must be prescribed an epinephrine auto-injector and referred to an allergist 3, 7
Patients should carry the epinephrine auto-injector at all times and be trained in its use 1, 2

Patients trying new medications should have antihistamines and epinephrine available, as some medications contain alpha-gal 7
High-fat dairy products pose a greater risk due to higher alpha-gal content 7
Gelatin-containing products and medications can trigger reactions 3, 7

The lack of pruritus in the presence of bradycardia and hypotension helps distinguish vasovagal syncope from anaphylaxis 1
Approximately 1-7% of patients experience biphasic anaphylaxis, with risk factors including severe initial presentation and requiring >1 dose of epinephrine 1, 2