This swelling could be angioedema, which causes tissue swelling.
Angioedema may be caused by an allergic reaction. It is associated with the release of histamine and other chemicals into the bloodstream. The body releases histamine when the immune system detects a foreign substance called an allergen.
Some of the common causes are drug allergy (caused by certain medications), emotional stress, exposure to water, sunlight, cold or heat and pollen.
Foods (such as berries, shellfish, fish, nuts, eggs, milk, and others) and insect bites are other trigger factors but you will be aware of this. Sometimes the cause of angioedema is never found.
Since yours seems to be a seasonal problem, it could be the pollen that is triggering this reaction. Since you mentioned stress, that could be adding to the problem.
Angioedema is a swelling similar to hives, but the swelling is beneath the skin rather than on the surface as in the case of hives.
You can take antihistamines and anti-inflammatory medicines (corticosteroids) to treat this condition. Cool compresses or soaks can provide symptomatic relief.
OMG the same thing just happened to me about 4 days ago. I thought it was just a pimple so i popped it two days ago and put toothpaste on it and washed it and stuff and now there's like a small circular bump there and the certain spot get warm at times like its heating up...SOMEONE PLEASE HELP ME!! I hope its not a permanent scar??
I've been having this happening to me for like a year now and have been to an allergy specialist and he states they can't find what i'm allergic too and it's stressing me out because the only thing that helps with it is steroids....please help i'm at a loss of what to do next???