Thanks for writing to us.
After an analysis of the history described by you it could be an infection of sweat glands and hair follicles in the arm pit coalased , a term applied to it called "Hydradenitis
The infection could have been caused by gram positive "Staphylococci" It could also be a Staphylococcal Impetigo
You have to undergo detailed routine blood and urinalysis
including a culture and sensitivity for the Pus .Depending upon the report ,a treatment can be instituted. The investigations are essential to establish /rule out co morbid conditions such as Diabetes/immunodeficiency
In the meanwhile ,when the reports are being awaited, cleaning and dressing of the area/prophylactic antibiotics/anti inflammatories/vitamins
Supplimentation/Hot fomentation can continue.
Wishing you Speedy recovery.
Dr Lt Cdr ASN Bhushan,