Heat rash help?

[Jake1988]

Hello,
During exercise, about 90% of the time, I will develop some sort of heat rash on my arms, the back of my hands, and possibly on my torso, although I'm usually wearing a shirt while exercising and I don't really check. The rash on my arms and hands comprises of small, red spots, and is usually on the underside of my arms (and the back of my hands). Sometimes, I have small, flesh-coloured bumps as well, which are quite itchy. Sometimes I seem to get this rash in the shower, strangely enough it always appears towards the end of my shower. Also, in situations where I am hot and flustered, in crowded areas like buses and trains, hot weather etc. the rash sometimes appears.

I've tried many things to combat this rash, such as exfoliating my body in the shower, using a different shampoo and soap, and using a different washing powder. However the success of these actions has been limited. I would like to know what I can do to get rid of this rash, and stop it from appearing in the first place. I am a fairly athletic person, so you can imagine that this is quite an annoying problem to deal with. I suppose I should also mention that I haven't had this rash all my life, it's only appeared in the past 2 or so years.

Any help would be much appreciated.

[bezzabezz]

Hey man, I know this is 5 years old but would be really interested in whether you found a way to stop this? Everything you've said is the same as what I've been experiencing and I also thought that maybe it was due to the blockage of sweat ducts. I figured I'd try exfoliating regularly to see where that would get me, but would really like more information on this. Thanks (if you ever even see this).

[Bhupinder Kaur, MD]

Hello,
From the symptoms it can be cholinergic urticaria. It  is a form of chronic hives that is caused by an increase in body temperature but can be idiopathic also. Take some antihistaminic like Benadryl or Claritin and apply some calamine lotion on the hives. If the symptoms persist then please get it examined from a dermatologist.
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.

[Jake1988]

Hi, thanks for the reply.
There are no other symptoms when this rash appears, however it usually lasts longer than 5-10 minutes. The itching may go away, but the rash itself may persist for half an hour or more. Due to the fact that there are no other symptoms, I would probably rule out anaphylaxis, and also the rash is not severe enough to stop me from exercising - I usually keep going, although it can be quite irritating.

I think that the rash is most likely associated with heat - it happens not only while exercising, but also in hot, crowded areas and sometimes in the shower. Also, I haven't broken a sweat in a while, which leads me to think that maybe there is a blockage of my sweat ducts, which traps the sweat under the skin, and subsequently causes a rash.

So what I would like to know is how I can prevent this heat rash and/or unblock my sweat ducts. I have read all over the internet that the best way to prevent heat rash is to avoid hot, humid areas and exercise, but that is absolutely absurd to me - there is no way I'm giving up exercise, and I can't escape the hot weather here in Australia, haha.

Is there anything I can do?

[Bhupinder Kaur, MD]

Hello,
From the symptoms the possibility of exercise induced urticaria needs to be ruled out. Most symptoms can be controlled by taking antihistaminics like benadryl or Claritin or zyrtec. Slow down or stop your exercise as soon as symptoms start. You should always exercise with a partner who knows about your condition.

In some people, eating certain foods before exercise may make allergic symptoms more likely to occur. Keep track of what you eat before exercising for a few weeks. If you notice a pattern to your symptoms that seems related to a certain food, stop eating it for a while and see if the hives stop.Also, do not exercise for 4 to 6 hours after you eat.

You should stop exercising as soon as you notice the hives. If the hives don't go away in 5 to 10 minutes, or if you have other symptoms, call your doctor right away. It can be Exercise-induced anaphylaxis.

Also wear medical alert jewelry or ID tags describing the condition and sensitive substances and always carry a self-injectable epinephrine kit (Epi pen). 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.