Yellow Gourami White Lumps...help?

[Sazi]

I just noticed on my yellow gourami that it has a line of white spots on its top fin but I have no idea what it could be. None of my other fish from what I can see have anything but I am worried it will spread to them so have separated it. I took a photo but it won't upload due to being too big. Will try and get a smaller one

Any ideas what it is and how to treat it please?

Than