Anosmia (Smell Loss)
WHAT IS ANOSMIA?
Anosmia is a total loss of smell, and a decrease in the ability to smell is called hyposmia. The causes of hyposmia and anosmia are diverse, ranging from a simple viral cold all the way to an intracranial skull base tumor that has damaged the nerve responsible for smell. The complexity of smell loss is exactly why you need an experienced nose and sinus specialist. Houston Anosmia Specialist Dr. Arjuna Kuperan is one of the few fellowship certified Rhinologists in all of Texas with specialized expertise, experience, and skills in treating patients with all causes of smell loss.
CORONAVIRUS-RELATED SMELL LOSS
The most common cause of smell loss is any virus that causes an upper respiratory infection, and we now know that COVID-19 has become a major cause of anosmia globally. In fact, smell loss can be one of the initial presenting symptoms of infection with COVID-19.1 If you are experiencing sudden anosmia or other COVID-19 symptoms, please seek medical attention immediately.
ANOSMIA (SMELL LOSS) TREATMENT IN HOUSTON
Anosmia, or smell loss, is a condition that can be reversible. With smell loss, time is a critical factor, because the sooner treatment is initiated the more likely the sense of smell is to return. Anosmia is often associated with dysgeusia, or taste loss, and the two conditions often occur at the same time. In order to have sophisticated taste beyond the basic tastes of salty, bitter, sweet, or sour we must have a normal sense of smell. The good news is that some patients will spontaneously recover their sense of smell without any intervention. However, for other patients, there are interventions such as treatments with oral or topical steroids and olfactory training that may be necessary to recover smell function. There are many causes of smell loss and the key to treatment is seeking a rhinologist who can identify the root of the cause and advise the appropriate care plan.
CAUSES OF ANOSMIA (SMELL LOSS)
The two major types of smell loss are conductive smell loss and neural smell loss. Conductive smell loss results from nasal obstruction that blocks the passage of air odor molecules, while neural smell loss is the result of a damaged or defective olfactory nerve. Conductive smell loss is generally easier to treat and up to 70% of anosmia is conductive smell loss as the result of conditions such as nasal polyps or sinusitis.2 Neural smell loss can be a congenital condition or occur as the result of head trauma, a sinus or skull base tumor, or an infection.
HOW IS ANOSMIA TREATED?
If the symptoms of anosmia or hyposmia are present it is always essential to consult a Rhinologist immediately for an accurate diagnosis and treatment plan. Nasal endoscopy (looking inside the nose with a small camera) is essential to better assess the problem and determine whether it is a conductive or neural cause of smell loss. A longer delay in starting treatment can lower the chance that the sense of smell will return.
If a viral cold is the cause of smell loss, oral steroids can be prescribed immediately. Olfactory training, which is like physical therapy for smell loss, has shown promising results in patients with sudden smell loss that have not responded to oral steroids.3 Conductive causes of anosmia like nasal polyps or nasal obstruction may require medical treatment and if this fails may require endoscopic sinus surgery.
Neural smell loss caused by sinus infections may be treated with antibiotics and oral steroids. Persistent infections may require a procedure, such as a balloon sinuplasty or endoscopic sinus surgery, in order to improve sense of smell and other symptoms. Severe neural causes of smell loss like sinus and skull base tumors may require advanced endoscopic sinus surgery or anterior skull base tumor resection.
1 Centers for Disease Control and Prevention. Symptoms of Coronavirus. Available: https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html Accessed May 8, 2020.
2Li X, Lui F. The National Center for Biotechnology Information. Anosmia. Available: https://www.ncbi.nlm.nih.gov/books/NBK482152/ Accessed May 8, 2020.
3 Hummel T, Rissom K, Reden J, Hähner A, Weidenbecher M, Hüttenbrink KB. Effects of olfactory training in patients with olfactory loss. Laryngoscope. 2009 Mar;119(3):496-9. doi: 10.1002/lary.20101.
Dr. Arjuna Kuerpan has either authored or reviewed and approved this content.