I have had syringoma for years and have also had several dermatologists tell me they can't help me and don't know what it is. Syringoma is caused by an over production of oil and it's a harmless tumour caused by a blockage. Normally they are skin coloured and look like flat bumps.
I also have milia, it is distinctive in how it looks, it has a white ball within it, which is keratin. It can be removed with a sterile needle but would recommend going to a professional for this.
Diathermy can be used for both issues, I've had this treatment several times.
It does help but you may need several treatments to get rid of them. Mine have reduced but it's likely I will always have them.
It does hurt but it's over very quickly, a bit like plucking eyebrows. I had a lot so asked for numbing cream.
The plus side is there is very little down time. I was red immediately after but this settled after day 2 and it looked like tiny scabs, the syringoma shrink and fade.
You should avoid the sun, hot showers, saunas etc (I didn't cook after my treatment, just in case, hehe)
I hope that helps.