Very small but tender lump under left arm

[ag3982]

I just noticed today that I have a small, somewhat tender lump under my left arm.  It's very small and I really didn't notice it at first, but over a few hours it felt like a had a dull pain in my armpit and when I went to "check it out" I noticed the bump.  It's just under the skin and probably no bigger than 4 to 5mm (under a centimeter).  It's located near the "edge" of my armpit, closest to my chest/pec muscle, just inside the armpit.

This is the second time this has occurred and I think it's the exact same area as before - if not exact, it's very close.  The last time this happened (2 to 3 months ago) the lump and pain went away after about 1 to 2 days.

Throughout this year I've been struggling with severe allergies and just next week I'm seeing an MD/allergy/asthma specialist to begin allergy testing (and eventually allergy shots0.  A few questions:

1.  Would a "tender" or painful lump typically be an infection or ingrown hair or something like that?

2.  How often would pain/small lumps be something to be concerned with (i.e. cancer)?

3.  How long should I let this go until I contact my doctor for examination?

4.  Could this be related to my allergies?  Is this something to bring up with the MD (board certified allergy-immunology) next week or should I just go to my primary care physician with this?  Today I stopped my allergy medication in prep for the testing next week.

5.  If this was something "nasty," I'm assuming it probably wouldn't "come and go" and would either stay the same size or grow over time.  Correct?

Any input/advice is appreciated.

[Kevin Pho, MD]

To answer your questions:
1) Folliculitis or a cyst can be one cause of the lump.

2) Other, more serious, causes would be a lymphoma (cancer of the lymph nodes).

3) If there is any concern, I would not hesitate in having this evaluated by your personal physician.

4) I would go to your PCP.  I am not aware of an allergy leading to this symptom.

5) Not necessarily.  Enlarged lymph nodes and sometimes cancer can result in fluctuating lymph node size.

These questions should be discussed with your personal physician.

Followup with your personal physician is essential.

This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.

Kevin, M.D.
kevinmd_

[spade22]

Hi,

I have a current situation that bears some simularity to yours.

I noticed a small, painless, hard, pea-sized lump just shy of my arm pit 10 days ago.  After a week, it hadnt changed in size, so I went to my family doctor who said that it was most likely due to fluid drainage (and then build up) which can be more prevalent at different times of the month.  His recommendation was to wait a full month (for my cycle to complete itself) and then return if the lump is still there and doesnt decrease in size.  In my case, it was well worth going to the doctor for this diagnosis/reassurance.  Incidently, my doctor was able to make this determination based solely on feeling the lump and its location - no invasive procedures were required.

I have also had similar lumps, which were painful, as an immune reponse to Shingles and a bladder infection.  In each case only one lump was present and was located either on the breast tissue or under the arm; both lumps took about 10 days to subside.

Take care.

[DaleJrFanCar8]

I've had these cyst like things uder my armpit & on the bottom side of my arm. I have been puting hot compresses on them & they will come to a head & pop. When it pops it will have some puss & some blood. After a while though it will come back. Do you think this is somekind of infection & need antibiotics? Thank you.

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