I’ve had it and continually look out for a recurrence. It’s like nothing’s there one day, the next day...a pimple...a few days later a good sized wart...quarter to three-eights inch tall soon. Itchy and painful. My dermatologists/plastic surgeon cuts it out. Had several...chest, arm, leg. The doc tells me, when I hit ten, he’ll give me 25% off a facelift. He gave me a punch card. LOL.
Oh man, that’s so awful! Seriously! I am sorry you have been going through this! I have an in-law who had it and still careful, but he only had it the one time some years ago.
My Dad kept getting squamous cell carcinomas and also melanomas.
I don’t know if it helps or not for Merkel cell, but I found this in the NEJM and asked his surgeon about it and he said he had seen it, too, and enthusiastically recommended it (Vitamin B3 prevents recurrence of squamous cell by 70%). This is a quality study:
https://www.nejm.org/doi/full/10.1056/nejmoa1506197
NAC is effective against non-metastatic melanoma cell lines, but can actually cause proliferation of metastatic cells, as it interferes with the body’s natural cytotoxic T cells. Resveratrol is effective against both:
https://iovs.arvojournals.org/article.aspx?articleid=2149048
In case they have the same effect in Merkel cell, something to consider and discuss with your doctor. (As in, you might want to think twice about taking NAC without asking your doctor about it first.)
The above is not anywhere near the calibre of the NEJM study. There are mainly only in vitro and mouse studies available on NAC and Resveratrol re skin cancers. Still, something to consider.