An allergy occurs when the body’s immune system responds severely and inappropriately to a stimulant that is often otherwise harmless. The immune system naturally differentiates between “self” and “non-self” molecules. When a foreign invader, such as an allergen (a substance that causes an allergic reaction) invades the body, the immune system attempts to isolate and rid the body of it. Common allergens may include certain foods, such as peanuts or shellfish, airborne allergens including pollen, dust and animal dander, insect stings, medications such as penicillin or aspirin, and surfaces such as latex or nickel.

An allergic reaction is triggered immunoglobulin E (IgE), which is an antibody. The antibody-IgE complex causes well-known allergy symptoms such as congestion, runny nose, watery eyes, itchy skin, swelling, hives, cough, chest tightness, shortness of breath, wheezing, and in extreme cases, anaphylaxis. Anaphylaxis is characterized by severe airway constriction, which prevents the patient from breathing, as well as extreme dilation of the blood vessels, causing a decrease in blood pressure.

Atopic patients, those predisposed to allergic hypersensitivity, often have a family history of allergies (such as asthma, hay fever, or eczema) and will usually exhibit a positive skin test. There are two categories of allergens – seasonal and perennial. Seasonal allergens include pollens and occur during the pollination months of plants. Perennial allergens are present year-round, and are often considered “indoor” allergens, such as pet dander, mold, and dust mites. In order to determine which of these you are allergic to, it is possible to do either a skin test or a blood test. A skin test requires the allergen to be put on or into the skin, and changes are observed for 10-15 minutes. Up to 54.3% of US adults have positive reactions to one or more allergens.

Once the allergen is determined, several preventative measures can be taken. For example, environmental modifications to remove the allergen or complete avoidance of the allergen can be tried. Medications used to manage allergies include antihistamines, anti-inflammatory medications such as steroids, or decongestants. In times of severe reaction (such as anaphylaxis) it may be necessary to administer epinephrine, which would allow for opening of the airways and restoration of blood pressure.

Nasal obstruction is commonly referred to as a “blocked nose.” This is frequently characterized by an irreversible problem, which is a commonly a structural displacement or deformation of the nasal septum (the cartilage and bone that separates the two nasal cavities), or weakness of the nasal valves.  The nasal valves are formed by the cartilaginous support of the nostrils. Structural causes of nasal obstruction may result from trauma or could occur during birth. Reversible nasal obstruction is a result of problems such as allergies, infection, hormones, or medications. Common symptoms of nasal obstructions include “stuffiness” as well as dry mouth, sore throat, facial pain and pressure, excessive snoring, halitosis, and decreased sense of taste and smell. Depending on the type of nasal obstruction, medical or surgical intervention could be of benefit.

A deviated septum is an anatomic nasal obstruction which benefits from surgical intervention. A deviated septum occurs when the bone and cartilage that separates the nasal cavities deviates to one or both sides. This can often cause problems such a blockage of airflow, dryness, and sometimes contributes to recurrent infections. Prior to surgery, to relieve the symptoms a patient could use saline rinses, topical nasal steroids, decongestants, or possibly antihistamines. Surgical reconstruction of the septum, or septoplasty, alleviates the contribution of the deviated septum to the sensation of nasal obstruction. This surgery is minimally invasive, leaving behind most of the cartilaginous nasal structure, and should not alter the patient’s appearance. Surgical reduction of the turbinates, structures located on the side walls of the nasal cavities, may also aid in opening the nasal cavity for improved airflow. Rhinoplasty may compliment a septoplasty to improve the visible shape or appearance of the nose.

Sinusitis refers to inflammation of the sinuses. Sinuses are hollow cavities in the face and skull which produce mucus. These sinuses include the ethmoid (located between the eyes), maxillary (located in the cheeks), sphenoid (located behind the eyes) and frontal (located in the forehead) sinuses. Normally, the mucus produced by the sinuses drains into the nasal cavity. However, when an obstruction is present mucus and pressure can build up, allowing for bacterial growth. Cilia are finger-like projections in the mucous membranes that sweep away mucus, bacteria or other debris. If they are not functioning, these particles are not cleared and symptoms can present. Sinusitis is more commonly called rhinosinusitis, due to the involvement and inflammation of the nasal cavity in addition to the sinuses. There are several different forms of sinusitis: acute, subacute and chronic sinusitis.

Acute sinusitis normally lasts from 1 day to 4 weeks. Acute rhinosinusitis most frequently results from viral infection, but may occur from bacterial infection as well. Subacute rhinosinusitis is a sinus infection that ranges in duration from 4 weeks to 3 months. It is often treated in the same method as acute sinusitis. Chronic rhinosinusitis is defined by symptoms that last longer than 3 months.

Different symptoms present themselves depending on the location of the infection or inflammation. Maxillary sinusitis presents with pain or tenderness behind the cheek bones or in the upper teeth, congestion, and purulent drainage. Frontal sinusitis is characterized by pain or pressure in the forehead, which is sometimes described as a headache. Ethmoid sinusitis presents with nasal congestion, pain or pressure around the eye, drainage, decreased sense of smell, and possibly pressure or headache. Sphenoid sinusitis presents deep-seated headache and postnasal drainage, but may be severe enough to cause fever or vision disturbances.

The main method in treating acute sinusitis is antibiotics, since many of the infections are bacterial. To relieve the symptoms, the physician may prescribe nasal saline rinses or nasal corticosteroids to reduce the inflammation. Decongestants may also be helpful to control symptoms. In chronic sinusitis, the mainstays of therapy include saline rinses and topical steroids, with some benefit being gained from antibiotics and oral steroids.

Fungi produce spores during their reproductive cycles. When a human inhales or comes in contact with these spores, they may cause a fungal infection, or incite an allergic-type inflammatory reaction. Fungal infections are considered opportunistic – meaning that while fungal inhalation is harmless most of the time, it may not be to a patient who is immunocompromised. When fungal spores enter the system and the immune system is not able to properly react, the fungal spores can germinate and grow inside the human host. There are fungal causes to such diseases as bronchitis, pharyngitis, rhinitis, stomatitis and sinusitis. If the body’s allergic reaction to the fungus is hyperactive, severe inflammation can be seen.

Fungal sinusitis: There has been no definite relationship between people with chronic sinusitis and fungus, since a positive fungus culture can be found on many people who do not have sinusitis. Acute invasive fungal sinusitis targets immunocompromised patients. In chronic invasive fungal sinusitis, fungal infection of the tissues is present, but the time course and severity of disease is less than in the acute form. A mild form of fungal sinusitis is a “fungus ball” which is a benign fungal growth, often in those with normal immune systems, which can easily be surgically removed. Allergic fungal sinusitis is caused by the presence of fungus and the body’s reaction to it, and is usually treated with both surgery and anti-inflammatory medical therapies. Acute and chronic fungal sinusitis is treated with antifungal medicines and surgery.

Stomatitis: Stomatitis refers to infection of the oral cavity. Fungal stomatitis is often characterized by white or yellow “fuzzy” or “curd-like” patches in the mouth. This responds well to topical antifungal medicines.

Pharyngitis: Pharyngitis is the inflammation of the throat. Fungal causes are determined by the presence of white plaques seen throughout the oral cavity. Topical antifungal medication is the usual treatment.

Nasal polyps are a common cause of nasal obstruction. Nasal polyps are small, benign and painless growths from the mucous membranes of the nasal cavity and sinuses. Nasal polyps are caused by accumulation of fluid, and represent the end-point of severe chronic inflammation. Nasal polyps are often found in patients with allergies, asthma, cystic fibrosis, or allergic fungal disease. A more severe syndrome of nasal polyps is found in those patients who have allergies, asthma, and aspirin sensitivity. Nasal polyps often vary in size from very small, which have no real adverse health effects, to large enough to completely obstruct the nasal passages. In the case of large nasal polyps, difficulty breathing, stuffiness, facial pain, headaches, loss of smell and taste, and a runny nose can be major issues.

Nasal polyps can be medically treated with corticosteroids, which reduce inflammation, but in many cases surgery may be necessary. Additional medical therapies may be of benefit in certain cases. Proper management of nasal polyps in patients with asthma has been shown to have beneficial effects on asthma-related symptoms and medication use. Nasal saline rinses are also recommended for proper upkeep of your sinuses.

Smell and taste are considered types of chemosensation, which is the neurological sensing of a chemical stimulus.

Olfactory sense neurons of are located in strategic areas within the nasal cavities. These olfactory sense neurons connect directly to the brain through the olfactory bulb. When exposed to a stimulus, the olfactory nerve endings react, delivering an electrical impulse to the brain, which then identifies the smell. This pathway is extremely sensitive, and may become altered with head trauma or respiratory infections. 

Common smell disorders include hyposmia and anosmia. Hyposmia is the reduced ability to detect odors while anosmia is complete inability to detect odors. Common causes of smell disorders include nasal obstruction, such as polyps, changes in mucus character, or structural deformity. Medications, hormonal imbalances and age also affect the sense of smell.

Taste buds of the tongue called house gustatory cells, which react to the presence of food particles. Taste sensations are either sweet, sour, salty, bitter or umami (savory). Humans are born with over 10,000 taste buds. Disorders of taste can be caused by poor oral hygiene and dental problems, alterations in saliva character, head injury, medications (most notably chemotherapy) and certain surgeries to the nose, ear or throat. One must be aware that flavor is a combination of both the taste and smell systems.

Most headaches people experience are tension headaches. Most “sinus headaches” are actually migraine variants. In fact, the International Headache Society Classification of Headache disorders does not include “sinus headaches” as a category. However, many patients with rhinosinusitis and/or allergies describe sinus headaches as pain or pressure behind the cheekbones, eyes, or the forehead. These headaches are often accompanied by other sinusitis symptoms such as congestion, nasal discharge, decreased sense of smell, and sometimes even facial swelling. A sinus related headache is thought to occur when mucus or pressure from the sinuses cannot efficiently drain into the nasal cavity due to inflammation or obstruction.

Sinus headaches must be treated by determining the cause of the inflammation. Allergens can often cause inflammation, so antihistamines could be used in this setting. Decongestants could also be used to help temporarily decrease mucosal swelling. If the inflammation was caused by bacterial infection of the sinuses, antibiotics may be of benefit. Overall, to prevent sinus headache, it is important to take preventative measures such as cleaning out nasal cavity through rinsing methods, avoiding allergens, and proper nasal ventilation. If there is any doubt to the origin of a headache, examination (including nasal endoscopy) may be coupled with a CT scan to see if there is sinus disease in the region of the pain.

The sinuses are separated from the brain by a layer of bone and the tissue layer that protected the brain, called the dura. Between the dura and the brain is a space filled with fluid known as cerebrospinal fluid (CSF). When there is a communication between this space and the sinuses, patients may notice clear drainage from the nose and a salty or metallic taste. CSF leaks can occur from trauma, surgery, tumors, or underlying brain disorders. If there is herniation of brain tissue into the sinus, this is referred to as a meningoencephalocele. The origin and size of the defect may determine the appropriate treatment. It is believed that continued CSF leak or untreated meningoencephaloceles place the patient at some risk of bacterial spread into the brain from the nasal cavity, known as meningitis. The vast majority of CSF leaks, meningoencephaloceles, and skull base defects of the sinuses can be surgically closed in minimally-invasive endoscopic procedures.

Dysthyroid orbitopathy, or thyroid eye disease, is an autoimmune disease process. The muscles of the eyes and fatty tissue around the eye swell, causing a bulging eyes, eyelid retraction, and possibly even vision impairment. Often, dysthyroid orbitopathy is associated with hyperthyroidism, a disease that occurs when the thyroid gland secretes excess hormones. Diagnostic procedures include testing for hyperthyroidism, and a series of examinations performed by an ophthalmologist. To treat the swelling and inflammation, corticosteroids may be prescribed and thyroid function is normalized with the help of an endocrinologist. In cases which do not adequately respond to medications, surgical decompression of the orbital cavity may be performed. This allows the swollen tissue to prolapse or herniate into the sinuses, relieving pressure on the eye and optic nerve, and allowing the eye to sink back into its native position.

Tearing (epiphora) is characterized by overflow of tears. This occurs when tears are unable to drain into the nose through the nasolacrimal system. Tears are produced in the lacrimal gland in the outside corner of the eye, and cross the eye into the lacrimal sac, which directs the tears into the nose through the nasolacrimal duct. When there is obstruction of this duct, drainage of the tears cannot occur and they accumulate externally. Nasal blockage could occur from a variety of causes, such as inflammation, infection, structural defects, trauma, or growths. Proper diagnosis requires thorough examination and testing by an ophthalmologist. In some cases, opening of the lacrimal sac is recommended, and can be performed in a minimally-invasive endoscopic outpatient procedure known as endoscopic dacryocystorhinostomy (DCR). 

Orbital tumors may occur anywhere in the orbit, the bony cavity that houses the eyeball, muscles, fat, and nerves and arteries of the eye. The orbit and sinuses have a shared common boundary. In some cases, this can be exploited to access nearby tumors with an endoscopic approach through the sinuses. Orbital tumors can be benign or malignant, and may require a biopsy to diagnose. A video interview with Dr. Ramakrishnan is available on the website​ that discusses this approach.

Benign tumors are non-cancerous growths. Symptoms mimic those of sinusitis, and often take some time to discover. Most benign tumors of the sinuses are treated with biopsy and surgical excision. Our center specializes in the minimally-invasive endoscopic approach to tumor excision.

Fibroosseous lesions are one category of benign tumor. Many of these are discovered incidentally, and do not necessarily need to be removed unless they are specifically troublesome to the patient.

Malignant tumors of the sinuses are uncommon, but can occur. A number of different types of malignant tumors can be found in the nose and sinuses. Depending on the type of tumor, treatment may include chemotherapy, radiation therapy, surgical excision, or a combination of the three. Malignant tumors of the sinuses are particularly problematic because of their close proximity to the eyes, skull base, mouth, and face. Our approach to treatment of patients with sinus cancers utilizes a multidisciplinary team of many specialists, which has been shown to provide the best outcomes. This has been our experience as well, as the University of Colorado Hospital recently ranked the best in the region for cancer care according to U.S. News and World Report 2011.

Mucoceles are benign processes which can mimic tumors. An obstructed region builds up mucus, which can expand into surrounding areas such as the orbit or skull base. Diagnosis is made based upon the patient’s history and characteristic findings on CT and MRI scans. Surgical treatment is curative in the majority of cases.

For further information, please refer to the textbook "Sinonasal Tumors​", in which Dr. Ramakrishnan served as an author and co-editor.