Oregano oil is supposed to be good for allergies!

Oregano Oil
Other than its association with culinary purposes, oregano oil is also known as a powerful natural remedy for allergies. The oil, with its strong, herb-like scent, acts as a natural antihistamine that your body releases in response to an allergen. If you constantly struggle with sneezing, itching, coughing, and a blocked nose, oregano oil can help in mitigating these sinus problems.

SOURCE: https://www.southfloridasinusandallergy.com/unlocking-natures-remedies-using-essential-oils-for-sinus-allergies/