3 doctors weighed in:
Do allergic reactions constrict or dilate blood vessels?
3 doctors weighed in

Dr. John Overholt
Internal Medicine - Allergy & Immunology
2 doctors agree
In brief: Dilate
In the nose this leads to congestion and runny nose.
If the reaction is systemic, then blood vessel dilation leads to low blood pressure.

In brief: Dilate
In the nose this leads to congestion and runny nose.
If the reaction is systemic, then blood vessel dilation leads to low blood pressure.
Dr. John Overholt
Dr. John Overholt
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