Both of my armpits are very tender, bordering on painful, with small lumps formed under the skin, at one point the areas were blotchy and red. I've been sweating a lot lately because it's been unusually hot in Phuket for a couple of weeks and I seem to recall that the problem may be caused by the heat and the sweat glands working too hard or similar. Anyone else come across this one, before I decide to take a trip to the doctor? Cheers.

Do you have any fever?

How big are those lump?

From what you said I would think that it is blocked sweat glands and are turning into infection.

If not improved in a day or two then make your trip.

I had something like this about 5 years ago in one armpit. The doctor lanced me 6-7 times and put in pieces of gauze sticking out to act as drains, bandaged me up and put me on antibiotics for a few days.

Thanks for that, it's not a big problem, just very aggravating. It seems that the answer, courtesy of Mrs CM, is baby powder under the armpits after you shower, an old Thai remedy I suppose but it does work.