<s>[INST] My 22 year old son had a lump about 1 inch below his armpit painful had for about a week thought was zit tried to pop but it just got bigger finally went to dr an$ they said it’s mersa huh? I thought mersa was detected through a nose swab test should I be concerned? [/INST] Hi and welcome to Healthcaremagic.  I understand your concerns and I will try to help you as much as I can.This looks like swollen lymph nide. In many cases there are glands (lymph nodes) commonly swell when you have a cold or sore throat. More serious infections may cause the glands to enlarge and become very firm and tender. Also, considering your description this may be some other  benign subcutaneous lesion such as lipoma, fibroma or atheroma and if there are no skin changes such as redness, pus discharge or pain and fever then you should not be worried since it can be easily surgically removed under local anesthesia. Infections should be treated with antibiotics. If there is no improvement you should see ENT doctor.I hope I have answered you query. If you have any further questions you can contact us in every time.Kindly regards. Wish you a good health. </s>