Hairline and forehead when sweat or hot

[freeme3]

Hello--

I get a red rash on my forehead and into my hairline when I sweat, am hot, in the sun, after a hot shower, or if i am lying on my side sleeping and my head/face is pressed against the pillow.  I also suffer from dermographia and allergies.  

Does anyone know if this is a type of heat rash?

[Bhupinder Kaur, MD]

Hello,
Since you have the history of dermatographia, it can be due to 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.

[freeme3]

I want to add that it goes away after I cool down or move my head away from pillow.