It can be due to heat rash or milaria. Prickly heat (miliaria) is an itchy skin rash caused by trapped sweat. It tends to occur on areas of the body where skin touches skin, such as under the breasts, on the inner thighs, and under the arms. Tiny red spots with itching and pricking sensation are the characteristic appearance of this rash.
Avoid using any lotions and creams for the meantime. Use a mild cleanser with moisturizing properties like Cetaphil. Also use cotton clothes and change the clothes twice if there is any increased sweating. Try keeping the skin free of sweat as far as possible. If the symptoms still persist then you can apply mild steroid like dermacort. For the itching antihistaminics like Benadryl or Claritin can be taken.
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 dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
Yes, and a couple of more things to be aware of: If you have ever had a bad sunburn between your breasts then you will be suseptible to rashes in that area. After tanning, if at all possible, make sure that you take off your bra, put on a clean all cotton tshirt that will allow your skin to breathe. I agree whole-heartedly with the post about not putting lotion on the affected area. Powder/cornstarch is the best.
Don't rub or scratch the area or it will get worse. You could develope a secondary skin infection. Use rubbing alcohol to clean and dry the area, then put non fragranced powder on it. Heat Rash is the likely answer here.
Fungal rashes are easy to identify, they have blotchy patches with have a reddish turning to dark brown color and you will need to have a fungal cream for that. Not sure if the grapefruit juice is an answer there.
Scabies, if you have them, are more like tiny little red water blisters and appear between the fingers on the top of your hand. They are highly contageous.
Many people go to tanning beds because they have skin problems like eczema so always make sure your tanning staff know that you like to have your bed cleaned thoroughly before you get in.
Sweating is natural. I would not use antipersperents under the breasts, particularly any with parabens in them. (see below for parabens)
I'm not sure about bronzers and if they can enhance heat rash.
One very IMPORTANT thing to remember/watch for: check all of your bathroom lotions, shampoos, toothpaste, wetwipes and do not buy anything that has parabens in them. Parabens are proven to cause cancer and are used as a preservative in creams, lotions, shampoos, conditioners etc especially in the fruity kinds of lotions. Look up parabens online and throw away everything in the bathroom/cosmetics etc that have parabens in them. It's going to be expensive when you realize that toothpaste, bar soaps, wetwipes etc all seem to have those ingredients. A friend of mine was in tears when he told me to throw away all of my paraben products because his wife was just diagnosed with breast cancer. Don't take any chances. Parabens collect in the breast tissue.
I am a tanner at salons. FYI and get heat rashes often when it's the first time I've tanned in a while. So it comes with the territory. I was not sweating between my breasts during the tan. It was the heating up afterwards with a top on that didn't breathe which caused the heat rash. If one is burned from the sun or from a tanning bed then the skin tightens up and forms a layer of skin that is closed and the sweat underneath that is trying to come out of the pores that are now blocked or closed, can cause blisters from the sweat trying to get out.
Also note that you can get planter's warts from tanning beds also. I had that painful experience and so am very cautious about having the bed properly cleaned before I get in it.
I recommend covering the area between the breasts while tanning the first few times, or reduce the time for the first five sessions until you have a sufficent tollerance developed in the affected area.
Some antibiotics also cause photosensitivity so make sure if you are a tanning salon member that you ask your pharmacist about any medication your are on that might cause photosensitivity. Most of the time the medication comes with a sticker on the bottle to warn people, but in some cases, you wouldn't know.
Oh I should have said to expose the area to minimum gradual exposure to the light. ie when you first start tanning do listen to the salon staff about the number of minutes you should tan. Those first five or so times, leave area between the breasts exposed for one or two minutes and then cover up that area for the remainder of the tanning session so that you are not getting the full exposure for the whole time. This way you can develop a tan in that area without the burn and later on can expose the are without getting a rash.
It's not so much the sweating during the tan that is the problem as much is it what happens right after. So no bra, no tight or lycra clothing, do not exercise or do anything that causes sweating in that area. An ice pack can help at the first sign of itchiness. And remember, no lotion, use aloe vera for sun burn and for after sun care. Solarcaine Aloe Aftersun is what I highly recommend. Cheers!