What could cause a small, sore nodule just inder the skin in my armpit?
Sure, it could be an infected follicle, or it could be an infected lymph node. Keep it clean. If it gets bigger and more painful, go see your doctor ASAP. Hopefully it is just an infected follicle. Another worse possibility is that it could be a symptom of a systemic Staph infection (look up “MRSA” on Wikkipedia). It is getting much easier to catch nowadays from the community. If it is staph, you would have more and worse cysts to look forward to in the near future. Note that if the cyst gets big enough, they like to send you to a surgeon and have it cut out, leaving behind a large hole that will of course become a scar. Also, if you get to the point where it is draining pus, I’d suggest saving yourself a few steps and ask them right away to do a culture test. That way they can diagnose you early and get you on THE RIGHT antibiotics (if necessary) and save you a lot of trouble. Good luck.
