I have frequent episodes of flushing. At first it was mostly on my neck, shoulders and chest with it less frequently on my face and head. Now, however, I am flushing almost everywhere on my body. Is this symptomatic of small fiber neuropathy? My neurologist's nurse fielded my question and said you would pass it on to the doctor, but he has not returned my phone call in a week.

Serotonin reuptake inhibitors will do this.
Synthetic opiates also.

MSG in foods. Histamine releasing foods.

Niacin products.
ACE inhibitors for blood pressure .
And perhaps gabapentin/ Lyrica.

Serotonin is a biogenic amine also made
by some tumors in the body, and also
In an uncommon disease called Carcinoid
Syndrome.

Some foods contain serotonin -- pineapple and
bananas.

Here's another list of possible causes of flushing:

Flushing (physiology): Causes of flushing

Doc

Steroids are notorious for causing this pattern of flushing as well.

I was on my phone last night, so linking is very difficult for me.

If this is a "new" event, then you need to be a detective to see what is new for you.

Things like mastocytosis would be present since childhood, so this extreme form of histamine release would not be new to you.

But carcinoid and tumors would come on slowly. Carcinoid tumors in the GI tract would dump the serotonin in the liver for a long time until they metastasize outside the liver, and then the symptoms of flushing, wheezing, etc begin. Hidden lung tumors typically show up with flushing and sometimes behavior changes as the serotonin builds up in the body.

The major cause, would be the various drugs. Next comes foods.
In children often the first sign of food intolerance is bright red ears and/or face.

In adults the single most common flushing cause is alcohol use.
This can change with time and severity to become a purplish hue of the head neck and face which some advanced alcoholics display.

I think the only thing new to me is that I have been taking Gabapentin, but I think the flushing started occuring before that. Soon afterwards is when my body-wide burning sensation started.