It causes a cough that often brings up mucus. It can also cause shortness of breath, wheezing, a low fever, and chest tightness.
That sounds to me like you may have just gotten a blister. They come back a little crusty sometimes. I’d recommend going to the dermatologist, there are a lot of great ways to clear up acne with special medical care! There are also some helpful over the counter creams and medications. It doesn’t sound like any kind of skin condition, but you would be able to confirm or deny that if you went to the dermatologist.
Hope that helped! :)
A consequence you may suffer is an injury. Exercising without stretching can cause injury.