Anaphylaxis symptoms
Anaphylaxis symptoms begin within 20 minutes to a few hours. From person to person, symptoms may differ. Symptomatology is also different for different mode of exposure to the allergen. The presentation of anaphylaxis can worsen with multiple exposures, and may ultimately result in shock. The symptoms of shock are more complicated than allergy or anaphylaxis. [2]
Uniphasic or biphasic onset of symptoms
Most commonly, the patients may have monophasic presentation; anaphylactic symptoms, which occur and are resolved within a few hours. There is no correlated episode occurring afterwards.
However, in some cases, an initial phase of anaphylactic reactions may be accompanied by another episode later on, even after resolution of the earlier spell. It is also characterized by the fact that within the gap phase of normalcy, there has not been another exposure to allergen. The time lapse between the two episodes is variable. But at least 4-6 hours of observation are recommended in this aspect.