Approach to Anaphylaxis and Hypersensitivity Reactions

Immediate Assessment and Stabilization

• The American College of Oncology recommends stopping the suspected drug immediately and assessing for anaphylaxis using the ABC approach, positioning the patient appropriately based on symptoms, and administering intramuscular epinephrine 0.01 mg/kg (maximum 0.5 mg) into the lateral thigh if any criteria for anaphylaxis are met 1, 2, 3
• The British Journal of Dermatology suggests immediately discontinuing the suspected medication while maintaining intravenous access for potential resuscitation 1, 2, 3, 4
• The Annals of Oncology recommend assessing vital signs including blood pressure, pulse rate, oxygen saturation, and level of consciousness 1, 3, 4

Distinguish Reaction Severity and Type

• The Annals of Oncology suggest administering epinephrine 0.01 mg/kg (1 mg/mL dilution, maximum 0.5 mL) intramuscularly into the lateral thigh muscle immediately if the patient meets any anaphylaxis criteria 1, 2, 3
• The Journal of the National Comprehensive Cancer Network recommends repeat epinephrine every 5-15 minutes if needed, and initiate rapid fluid resuscitation with 1-2 liters normal saline at 5-10 mL/kg in first 5 minutes 1, 2, 3

Diagnostic Workup

• The Annals of Oncology recommend obtaining serum mast cell tryptase at specific timepoints for suspected anaphylaxis, with the first sample taken as soon as feasible during resuscitation (within 5 minutes to 3 hours) 2, 3, 9
• The British Journal of Dermatology suggests full blood count, ESR, CRP, electrolytes, liver function, coagulation studies, and skin biopsy from lesional skin for histopathology for severe cutaneous reactions 4

Monitoring and Follow-Up

• The Annals of Oncology recommend monitoring vital signs until complete resolution, with 24-hour observation required for severe reactions 1
• The Journal of the National Comprehensive Cancer Network suggests that if previous life-threatening reaction occurred, never use the implicated drug again, and consider desensitization for patients with prior reactions 5, 6, 7

Critical Pitfalls to Avoid

• The Annals of Oncology warn against delaying epinephrine administration while waiting for IV access or other interventions, and recommend having updated resuscitation protocol and equipment immediately available before any high-risk drug administration 1, 2, 3, 5, 6, 7