My husband had this thing appear 4 weeks ago, gp did a virtual appt gave him cream said it looks like a bite. It didn’t go completely and it’s come up, any ideas what this is? Any experiences? I googled it and what’s come up is cyst? Ingrown hair? Boil and when boil came up it said causes can incluse things like hiv and diabetes can cause them so I’m worried as never seen anything like this before thank you.