Even if the initial symptoms and signs of an anaphylactic reaction completely resolve with treatment, it is critically important to keep patients under observation in a hospital setting for specific durations. Patients presenting with respiratory distress should be monitored for 6-8 hours, while those presenting with circulatory disturbance should be monitored for 12-24 hours. This precaution stems from the risk of 'biphasic anaphylaxis,' defined as the reappearance of symptoms even after contact with the triggering factor has ceased. The primary risk factors for biphasic anaphylaxis, which can occur in approximately 21% of anaphylaxis cases, are:

* Delayed administration of adrenaline
* Low blood pressure (hypotension)
* Age group 6-9 years
* Wheezing (noisy breathing)
* Diarrhea
* Anaphylaxis due to drug allergy
* Idiopathic (unknown cause) anaphylaxis