Ethmoiditis is an inflammation of the ethmoid sinus, which is located between the eyes and plays a crucial role in the respiratory system. This condition often occurs as a result of a sinus infection or allergies, leading to symptoms such as nasal congestion, facial pain, and a reduced sense of smell. Treatment for ethmoiditis typically involves managing the underlying cause, which may include antibiotics for bacterial infections or nasal corticosteroids to reduce inflammation. In some cases, a doctor may recommend saline nasal sprays or decongestants to help alleviate symptoms and promote drainage of the affected sinuses.