I hope you are well by now.
Yes, allergies can cause a hearing loss in one ear, that is exactly what happened to me.
Hi,
It would be difficult to say anything without a detailed clinical evaluation. It would be best to consult your doctor or ENT specialist and get a clinical examination.
Since when have you noticed these symptoms? What is your age?
Have you had allergic reactions in the past? Are you allergic o any specific substances?
Do you have any pain or discharge frm your ear?
Let us know about how you are doing and if you have any other doubts.
Regards.