Allergic reactions can be caused by an array of reasons such as foods, chemicals, and season changes.
When an allergic reaction occurs, the body releases chemicals known as histamines. Histamines increase flow to the affected area and allows your immune system to step in.
For example: If you have seasonal allergies that are from pollen, your body will release histamines.
It signals your nasal passages to create more mucus and increase blood flow to the capillaries near your eyes leading to a stuffy nose and watery, itchy eyes.
If you experience dark circles under the eyes, it is recommended you observe when this is more noticeable. Is it during a particular season? Is it when you ingest certain foods?
If so, you can note what the cause is to avoid it. Sometimes it is difficult to eliminate the cause, especially if it is season-related.
Some steps you can take to alleviate allergic symptoms include taking over-the-counter antihistamines and use of eye drops to improve darkness and swelling under the eyes.