Possibly an ingrown feather... it needs to be treated somehow... and those feathers look horrid like some kinda bugs have ravaged them.. maybe lice or mites. I bred Silkies for a while and what I'm seeing when I scroll in close is not standard Silkie feathering as to reference for my suggestion. Are you able to seek veterinary care?
Can you please add you general location so we can make the best suggestions possible at a glance.. as it helps to know what resources might be available to you.
In regards to treating somehow... I have never faced this YET. So I THINK maybe a warm wash cloth soak to the effected area... trying to soften it and maybe draw anything to the surface... for a possible lancing to help release the feather... IF veterinary care is not an option. JUST brainstorming here.. please use you best judgement according to what YOU are seeing.