Armpit Rash and bumps

4 weeks ago, i got back from a one week vacation from my friend's house out on the lake, when i got home, i started noticing an itchiness in my right armpit. It started to look like a little tiny patch of a rash of some sort, as a week went by and it didn't go away, then i started getting bumps or "boils" that started appearing and hurting, a few zits here and there. But i didn't think nothing of it, so 2 weeks later, i started applying Tinactin antibacterial cream thinking it might had been some kind of bacteria of some sort. Then the "rash" started appearing pink and seemed like it was disappearing, but it still itched, The third week, i started getting more bumps underneath my armpit. During last week, 3 new bumps showed up, 2 extremely close to one another and they grew quite large, now it feels like i have a big knot in the middle of my armpit and its kinda painful to raise my arm.
I've never shaven my armpits.
i've used the same deodorant for the past year, no new detergent is being used.
i DO wear tighter t-shirts and my brother is 13 and has acne problems and likes using my towel to wipe his face with. could that be a cause also?
my friends suggested i just use cortisone.
but i want to be cautious and not use something that i'm not sure what it is and cause the rash to get worse.
I need help, what is this?
and how can i make it better?

[Bhupinder Kaur, MD]

Hello,
From the symptoms it can be boils or hidradenitis suppurativa. Hidradenitis suppurativa is a skin disease that affects areas bearing apocrine sweat glands and hair follicles; such as the underarms, groin and buttocks especially in women.

Apply warm compresses on the lumps and keep the area clean. Topical antiseptic treatment and topical antibiotics such as mupirocin or neomycin containing ointment is very useful.If still the lumps persist then specific treatment like antibiotics,vit A supplements,corticosteroid injections,isotretinoin,antiandrogens and sometimes excision and drainage ,laser therapy and radiotherapy are found useful. I feel that you should consult a dermatologist and discuss these options with him.

It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.

[Davyjones1993]

Well, is this contagious? Is it safe to scratch it when it itches, should i wash my hands when i touch it?

[Bhupinder Kaur, MD]

Hello,
Hidradenitis suppurativa occurs when sweat glands and hair follicle openings become blocked. It is not contagious and you cannot pass it to anyone. I hope it helps. Take care and regards.