pits may be due to several things. It may be due to a sweat rash, atopic and seborrheic dermatitis , contact and allergic dermatitis , folliculitis and hidradenitis suppurativa.
How would you describe the rash?
Is this itchy
For how long has this been present ?
Do you have any known allergies?
Avoid using any deodorant at this point. Wash the area only with mild and bland cleansers. If excessive sweating occurs ,try deodorant sprays instead of roll ons.