Hi. Thanks for your query. Noted the history and understood your concerns. Since there is enlarging red lump in the armpit in spite of Sulfamethoxazole and local application of Hibiclens and warm water with formation of white head, this is definitely an enlarging abscess secondary to infected cyst or a boil. I would advise you the following in such a situation: Continue Sulfamethoxazole. Apply liquid povidone iodine locally. Apply a sterile dressing twice daily, the abscess may open up, drain and get alright. Going to ER helps in clinical examination, tests of blood, particularly blood sugar and others. If required a formal incision and drainage may be needed. Take an anti-inflammatory medication like Ibuprofen thrice daily if it suits you.