Not sure about your friend's symptoms OP, as others have said he needs to see his GP.
However, on the subject of moles generally, and melanoma follow up, can I advise readers that the NHS provision for skin checks is now extremely limited and it is best to go private. There are quite a few providers offering skin checks (depending where you live) and a casual look at some suggests a price in the region of £150.
I have a sister in Australia who had major surgery for melanoma and is lucky not to have had recurrence due to the staging at the time. So as a family we do have heightened awareness. Another sister had a melanoma removed from her nose.
This is her recent experience after she sought advice regarding a mole her husband had seen in her back: (edited from her email)
"they then wasted their own appointment by sending me to see a useless ‘specialist skin care nurse’ who first of all lectured me for not going to see my gp if I had concerns about a mole , and then reluctantly agreed with the private consultant who had referred me for surgery, filled in a whole new set of forms and said I’d now have to wait for yet another letter which will most likely be delayed again by strikes and Xmas rush before I know when the surgery will finally take place! It seems they can send text messages when it suits, but not to arrange appointments 🤪
When I pointed out that it’s impossible to check for moles on your own back, hence I had no reason to see my gp, if indeed a face to face appointment could have been made, she came out with some guff that the immune system is very good at coping with melanomas so there was no need to worry. Plus, the NHS no longer follows up with mole checks as it is too stressful for most patients to keep going for appointments. I said I found it reassuring and certainly not stressful- but she was having none of it - said it was new NICE guidelines based on best practice blah blah blah .
(My bold).
I have advised her to complain about the nurse who appears to need education regarding the serious nature of melanoma.