Adrenaline intravenous therapy persistence grade I severe allergic reaction: A case report and literature review.

Rationale: At present, there is still insufficient understanding of the progression from persistent allergic reactions to severe reactions. Adrenaline remains the preferred medication for severe allergic reactions, and intramuscular injection of adrenaline can also be considered for patients with grade I reactions that are difficult to alleviate gastrointestinal symptoms. It is worth further discussing whether it is possible to break the conventional intramuscular injection recommended by the guidelines when the effect of intramuscular injection is not ideal for persistent grade I severe allergic reactions.

Patient Concerns: A young male, 20 years of age, was admitted to emergency department because of repeated rash for 3 days and abdominal pain for 6 hours after taking traditional Chinese medicine. After hormone therapy, the rash continued to recur and secondary gastrointestinal symptoms occurred on the 3th day. Adrenaline intramuscular injection was given to temporarily relieve the rash and abdominal pain, but symptoms still persisted.

Diagnosis: The patient was diagnosed with persistent severe allergic reaction (grade I).

Interventions: Continuous intravenous infusion of low-dose adrenaline under electrocardiographic monitoring, real-time monitoring of heart rate and blood pressure, and routine treatment with methylprednisolone, diphenhydramine, calcium gluconate, and cetirizine. During this period, adrenaline intramuscular injection is temporarily added when abdominal pain symptoms are obvious. The entire treatment process used a total of 6.8 mg of adrenaline.

Outcomes: During the entire period of adrenaline intervention, the patient did not experience any new discomfort, and there were no abnormal fluctuations in heart rate, rhythm, or blood pressure. The symptoms of rash and abdominal pain gradually improved.

Lessons: For patients with persistent grade I severe allergic reactions, intravenous administration of low-dose adrenaline under close vital sign monitoring is safe, feasible, and highly effective in preventing biphasic, persistent, or worsening allergic reactions.