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We have looked at a single anaphylactic reaction, but now we're going to look at the possible biphasic anaphylactic response. A biphasic response is where there are two separate and distinct responses that are separated in time. With anaphylaxis, this would be an immediate reaction to the trigger, which was followed by a recurrence of symptoms after an interval of time, and in that gap, no signs or symptoms. This reaction can occur between two and 72 hours and can happen after discharge from a hospital. These second reactions can occur in as many 20% of cases. The biphasic reaction can be less severe than, equal to, or more severe than the initial reaction, ranging from mild symptoms to fatality. Biphasic reactions happen in up to 1/3 of patients who have had an initial near-fatal reaction. These patients seem to have made a full recovery when severe bronchospasms suddenly reoccur. Predicting if a second reaction will occur is not easy. A higher chance of recurrence is more likely when the severe reaction has occurred and in cases where two auto-injectors were initially used. Being aware of a possible biphasic response is important if you are caring for someone so you can monitor the patient just in case. If you are administering first aid, it may be worth telling them, or their parent, to watch for additional symptoms even after discharge from a hospital. Knowing this is important. But remember, every anaphylactic patient is sent to a hospital and they will advise on the actual care they think is needed after discharge from the hospital. Finally, always make sure you have spare auto-injectors once discharged from hospital as a precaution, and the patient is monitored closely for up to 72 hours after the first attack.
Biphasic Anaphylactic Response: Understanding the Two-Phase Reaction
The Biphasic Anaphylactic Response
Two Distinct Phases:
Anaphylaxis is typically associated with a single reaction, but it's essential to explore the potential of a biphasic anaphylactic response.
Immediate and Recurrent Reactions
Exploring the Concept:
Biphasic response entails two separate and distinct reactions, with the initial response followed by a recurrence of symptoms after a time interval.
Recurrence Without Re-Exposure
Crucial Distinction:
Unlike a standard allergic reaction, a biphasic reaction can occur without re-exposure to the allergen, making it especially unpredictable.
Timing and Severity
Varied Onset and Impact:
A biphasic reaction may manifest within 2 to 72 hours after the initial incident, sometimes long after hospital discharge, affecting up to 20% of cases.
Severity Levels
Ranging Effects:
The subsequent reaction can be milder, equally severe, or even more severe than the initial response, presenting a wide spectrum of symptoms, including potentially fatal ones.
Unpredictable Symptoms
Changing Clinical Presentation:
It's essential to note that biphasic reactions may not exhibit the same symptoms as the initial reaction, adding to the challenge of predicting a second occurrence.
Assessing the Risk
Estimating Recurrence Probability:
Predicting a second reaction is complex, but higher initial reaction severity or the use of two auto-injectors may elevate the chances of a recurrence.
Care and Monitoring
Vigilant Observation:
If you're responsible for someone's care, close monitoring is essential. When providing first aid, consider informing the individual, parents, or guardians to watch for additional symptoms after hospital discharge.
Professional Guidance
Expert Advice:
While understanding biphasic reactions is crucial, it's important to remember that all anaphylaxis patients receive hospital care and are advised on necessary post-discharge precautions.
Preparedness and Monitoring
Securing Safety:
Upon hospital discharge, always ensure that a spare auto-injector is available. Vigilantly monitor the patient for up to 72 hours post the initial attack to be fully prepared for any possible recurrence.