I just recently had a 48 stomach flu. It went away on its own and I never had a fever with it. The next day however I had a swollen lymph node under my left arm. It is only slightly painful to the touch but I have developed a slight rash under that arm as well. I do NOT have a fever and I have had two people in the medical field who are nurses tell me that my lymph node may have got infection from the illness I recently suffered and that is what has caused my current symptoms. They have both said that the rash is most likely a heat rash caused by the swollen/infected gland. They said that swollen glands tend to give off heat. Do you think that is the case?? They have also said that the swelling and rash should go away as long as I drink plenty of fluids and apply warm compresses to that area. They told me to go to the doctor if the swelling has not gone down in the next two to three weeks.