did you have allergy testing done?
You should avoid using a deodarant directly to your under arm skin, avoid shaving or waxing the area for some time. These could be the cause of your symptoms.
Try to avoid sweat accumulation at the sites and use a powder.
Since when have you noticed the lesion?
This could be some insect bite, eczema or bacterial skin infection or dermatitis.
You could take oral antihistamine medications for the itching and apply calamine lotion at the site.
It would be best to consult a skin specialist as nothing can be said with surety without having a look at the lesions.
Let us know about what the doctor advises and post us if you have any other doubts.
wow i have the exact same thing im a 17 year old female...did you figure out what it was? its driving me crazy