Question

why is an untreated acute allergic reaction a life - threatening situation?
vomiting and diarrhea may cause dehydration
airway constriction may lead to low blood pressure and shock
peripheral vasoconstriction elevates blood pressure
none of the above

Explanation:

In an untreated acute allergic reaction, airway constriction can severely limit oxygen - intake. This lack of oxygen can lead to low blood pressure and shock, which are life - threatening. Vomiting and diarrhea causing dehydration is a concern but not the most life - threatening aspect here. Peripheral vasoconstriction elevating blood pressure is not the main life - threatening factor in acute allergic reactions.

Answer:

Airway constriction may lead to low blood pressure and shock