If this is occuring in the armpits and groins recurrently and always painful, you may be suffering from hiadrenitis suppurativa.
It is a condition that affects apocrine sweat glands, that can cause chronic scarring
and pus formation. Several treatment options are available including surgical resection.
Tight cloting, obesity exacerbate the condition, and humid climate conditions do not help.
Combination of rifampicin
helps in most cases, and 2nd line drugs include Vit A agents like roaccutane
Hope that helps.