Thanks for the query.
Yes it may be related.
There is a sympathetic and parasympathetic out flow of nerves from the spinal cord
If your fall has caused damage to these nerves their control over the vessels may lost.
In that case the vessels may remain dilated and produce redness
without any symptoms.
A photograph would have helped me in giving a closer diagnosis.
Please meet a dermatologist
and discuss regarding this.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.