Seems like you have developed an allergic skin reaction to deodorants.
Discontinue the use of the same.
Use some topical steroid
cream over the affected area.
Take oral antihistamines to relieve the burning sensation.
You might need oral antibiotics
if there is any infection.
are also needed in severe cases.
See a dermatologist
if the lesions tend to persist.
Hope it help,
Dr Geetika Paul