Hello and welcome to the forum
The first thing that came to mind for me is a virus called lymphocystis. Please google image it to compare pics. of infected fish. There is no true cure for it unfortunately. This doesn't necessarily mean a death sentence for the fish either.
There are other less common diseases and parasites that can look similar and would be more of a concern. Did you purchase these fish very recently? If so, can you contact the supplier and see if they have other fish showing the same symptoms? Here's a little blurb about treatment for you if you think that is what the fish has. Can fish with lymphocystis be treated?
Currently, there is no good treatment that will speed up recovery from this disease. Most often, the disease must run its course in an affected fish. Fortunately most cases of lymphocystis in warmwater fish will resolve on their own after a few weeks, as long as husbandry is good (good water quality/chemistry, good nutrition, correct population densities, optimal social groups) and as long as other stressors have been eliminated. Although it is not an ideal solution, at present, the best option is to hold fish for several weeks (longer for cool and cold water fish) until the lesions have cleared.
Because lymphocystis disease tends to develop in parts of tissues that are less exposed to the immune system (e.g., at the periphery, away from blood vessels that carry immune cells) and in tissues with a thick hyaline membrane that may "hide" these cells, an immune response normally does not develop until after cells have burst and released virus. There is some evidence that fish infected with lymphocystis will develop less pronounced lesions if they are re-infected or if lesions recur.
Culling (removing) infected fish from a population may help reduce overall loads of virus in the system as well as infection rate, but it is difficult to cull all affected fish because some infections may not be visible with the naked eye, and many less severely infected fish may remain in the population to potentially infect other fish. Culling, therefore, may not be as effective a measure for aquacultured populations as for hobbyists or display aquaria. Culled fish can be isolated until their lesions resolve, but lesions may recur. If they do, they will most likely be less severe.