This is not acne, so you may wish to re-post this in the dermatology forum as I am only an expert on acneic skin.
This is probably caused by damage to the hair follicle under the arm. Do you remove the hair there?
The skin is good at healing itself and a lesion measuring 1mm doesn't need stitches.
However, due to the length of time this has been a problem you should see your doctor incase a biopsy is indicated.
In the meantime, do not squeeze it. This will spread bacteria causing secondary infection and make diagnosis harder. It will also delay healing time.
I experience from acne under my armpits at times. Well, not any more. More in my teenagers years. But what you have is not acne and like loiloi say's you should see a dermatologist to get your problem fixed immediately.
In the meantime, don't do anything (touch, squeeze, pinch). Just go see your dermatologist.
Take care and let me know how it went!
Do a search on Hidradenitis Suppurativa, also called Acne Inversa.
Hidradenitis Suppurativa ( HS ), is a recurrent skin disease usually found in inverse areas and around hair follicles where apocrine sweat glands are located. It is characterized by boil-like lesions or abscesses on the groin, buttocks, thighs, scalp, neck, nipples, penis, vagina, scrotum, and armpits, with subsequent scarring and chronic seepage.
May want to go see a Doc to take a look and possible biopsy to be safe.
Best of luck
Your symptoms definately fit the description of Hidradenitis Suppurtiva. I too have this chronic condition and would highly recommend you see a dermatologist right away in order to start a treatment plan that can hopefully keep this condition under control for you. Best of luck to you.
I had a similar condition - very painful pimple-like nodule in each armpit. I stopped using deodorant and started using Goldbond powder several times a day. Over the last 4 weeks, the nodules have stopped hurting and disappeared.
I had the same problem so I went to my doctor, and it turns out it was a MRSA staph infection. First of all, don't panic. He prescribed antibiotic, which helped but didn't get rid of it entirely. It really just takes time for your body to fight the infection. I've had mine for almost four months and its finally clearing up. I suggest cleaning the infected area twice a day with hydrogen peroxide (to help keep the boils open) and alcohol, and then applying an antibiotic ointment and covering it with gauze and tap. I also scrubbed the area with salt occasionally, which hurts but seemed to help, and would apply a hot compress of salty water every few days to help the boils burst.
I am pretty sure I got the infection through a lack of hygiene, lack of sleep, overabundance of stress, and a poor diet. You might have to change your lifestyle a bit to help your body fit the infection. A helpful article is about this:
all my doctors are idiots and want EVERYTHING done with some crazy way, if that's the case, just wait a bit, put a damp cloth on it, or push anything hard out of it, it may hurt and show raw skin sometimes, but if you do it right, it will at lease leave a scar the size of the blemish or nothing a all, but its under your arm, so don't worry about a scar