Hi,
This reactions is known as
alcohol flush reaction.
When we consume alcohol, it gets metabolised in body by liver enzymes into acetaldehyde and then into acetate.
Alcohol causes vasodilatation of small blood vessels and capillaries and some times bursts this capillaries under skin leaving behind broken capillaries and red spots.
Also,alcohol causes diuresis by suppressing
vasopressin release from
kidney leading to extra work to the kidney and by this water comes out in bladder leading to depletion of water in body leaves skin dry,rough and itchy.
This all is direct effect of alcohol in body when consumed in excess,you can consider it as a
allergy.
The best way to cure allergy is avoidance of contact with allergen rather than taking antiallergic drugs like
steroids or antihistamines.
Some people(commonly Chinese,Japanese)have inability to convert this excess acetaldehtde into acetate leading to accumulation of this acetaldehyde into blood causing blood vessels to dilate more.
And because of this,our skin turns red and slightly burning to touch till this substance clears from the blood by kidney.
Best treatment is to curtail this alcohol consumptions.
Thanks.