Sinusitis Diagnosis

  • Diagnosis

    Sinusitis is an inflammation of the paranasal sinuses Figure 01. The paranasal sinuses are air-filled cavities in the facial bones that open into the nasal passage through tiny holes called ostia. Sinusitis occurs when the sinuses become inflamed and the ostia become blocked. In acute uncomplicated sinusitis, symptoms last less than one month, and may be treated by a generalist physician. Chronic sinusitis, defined as sinusitis of at least three months’ duration, may require the care of an ear, nose, and throat (ENT) specialist. Most doctors believe that chronic sinusitis is a result of a series of past infections rather than a single persistent infection.

    Click to enlarge: Paranasal Sinuses

    Figure 01. Paranasal Sinuses

    Sinusitis is usually caused by a defect in the muco-ciliary blanket that interferes with normal sinus drainage. Mucus-producing cells and tiny hairs called cilia line the sinuses, and together are called the muco-ciliary blanket. Mucus traps bacteria and other contaminants that enter the sinuses, and then the hair-like cilia sweep them away with a rhythmic, beating motion. Defects in this system can lead to a buildup of mucus and a subsequent sinus infection.

    Blocked ostia can also lead to a sinus infection. Sinusitis can result when the ostia are blocked, and the air within the sinuses is absorbed into the bloodstream. The negative pressure created by the blocked ostia draws air and fluid into the sinuses, producing a microbial breeding ground. White blood cells will then invade the sinuses to fight infection, further increasing the pressure within these openings.

    A viral infection can lead to sinusitis. A viral infection of the upper respiratory tract, such as a common cold, may lead to sinusitis by interfering with normal mucus flow, or by causing the nasal passages to swell, blocking the ostia.

    Bacteria cause nearly all cases of acute sinusitis. While the organism responsible for sinusitis varies depending on which sinuses are affected, Streptococcus pneumoniae and Haemophilus influenza are the most common causative agents in a community setting.

    When a person develops sinusitis in the hospital, Staphylococcus aureus and gram-negative bacilli are frequently the cause.

    A variety of other organisms can also colonize the sinuses of people with weakened immune systems. Fungi such as Candida and Alternaria, the bacteria Pseudomonas and Legionella, atypical mycobacteria, and in some cases parasites, can live and grow in the sinuses of people with impaired immunity.

    People with intact immune systems rarely develop fungal sinusitis, a chronic condition. Fungal sinusitis most often occurs in patients with asthma or nasal polyposis, and is usually caused by Aspergillus fungi. In diabetics, a rare but severe fungal infection called mucormycosis can develop.

    Acute sinusitis causes pain and tenderness in various locations on the face Table 01 Figure 02. Sinus pain tends to worsen when a person bends over or lies down. The tissue lying over the sinuses may also become tender and swollen. The pain can be felt above the eyebrow, or in the cheek and upper teeth, depending on which sinuses are affected. Pain can also occur between the eyes and behind the eye sockets, as well as along the upper sides of the nose. Some patients may experience pain in the upper half of the face, and their eyes may water and be sensitive to light. Others may experience swelling of the lower eyelids, especially upon waking in the morning.

    Click to enlarge: Areas of Pain and Pressure in Sinusitis

    Figure 02. Areas of Pain and Pressure in Sinusitis

    Nasal and post-nasal discharge, headache, malaise, bad breath, muffled hearing, and fever can also appear with sinusitis. The pressure caused by sinus blockage can lead to headache and muffled hearing. Bacterial proliferation in the sinuses can also lead to bad breath, and can trigger an immune reaction, leading to fever.

    Chronic sinusitis by definition lasts longer than three months. Symptoms are similar to those of acute sinusitis, but patients with chronic sinusitis generally experience sinus pressure rather than sinus pain. The symptoms of chronic sinusitis include nasal congestion and discharge (often of thick green mucus), postnasal drainage, and sinus pressure, all of which tend to be worse in the morning. Headache and low fever may also be present. A fever higher than 101.5° F (38.6°C) is rare in chronic sinusitis.

    Table 1.  Symptoms of Sinusitis

    Acute sinusitis Chronic sinusitis
    Pain/pressure in sinus area that is worse upon waking and stooping overTenderness and swelling in skin lying over the sinusesNasal/postnasal discharge containing pusCold symptoms lasting from 7 to 10 days Sinus pressure that is worse in the morningNasal/postnasal discharge that is worse in the morningFatigueMalaiseSymptoms of acute sinus inflammation lasting three months or longer

    Medical-related risk factors for sinusitis include allergies and asthma, placement of tubes into the stomach or trachea via the nose for feeding or breathing assistance, and diseases that produce mucus abnormalities, such as cystic fibrosis. Asthma and allergies can increase a person’s risk for sinusitis because they can cause inflammation of the tissue lining the nasal passages, which can interfere with normal sinus drainage. Cystic fibrosis causes a person to produce abnormally thick mucus, which also inhibits sinus function by making normal drainage difficult. Tubes placed in the nose can irritate the tissue lining the nasal passages, and also provide a route through which bacteria can enter and colonize the sinuses.

    People who smoke cigarettes are more likely to develop sinusitis. Over time, smoking damages the cilia, the hairlike cells of the sinuses that help to sweep away mucus and foreign objects that enter the respiratory system. When the cilia are damaged, bateria enter the sinuses more easily, thus increasing the likelihood that people who smoke will develop sinusitis.

    You are more likely to get sinusitis if you experience rapid changes of atmospheric pressure (barotrauma). Activities such as deep-sea diving, airplane travel, or jumping into the water feet-first and not holding your nose can force fluid into the sinuses and create a bacterial breeding ground within. If your immune system or muco-ciliary blanket is unable to rid your sinuses of the bacteria, you will be more likely to develop sinusitis.

    Dental infections can spread to the sinuses, leading to sinusitis. Good dental hygiene (brushing, flossing, and using an antibacterial mouthwash) can help prevent dental infection, and thus help prevent certain types of sinusitis.

    Physical obstructions of the sinuses caused by growths in the nasal cavity or a deviation of the nasal septum can predispose a person to sinusitis.

    Chemical irritation can increase the likelihood that a person will develop sinusitis. Cocaine abuse, or exposure to any chemical that can irritate the tissue of the nasal passages, can lead to sinusitis.

    People with weakened immune systems experience more frequent and more severe sinusitis that is difficult to treat. Conditions that impair immune-system function include HIV infection, diabetes (especially when blood sugar levels are poorly controlled), and leukemia. Leukemia patients and others undergoing bone marrow transplants are particularly vulnerable to sinusitis.

    Your doctor will take a history and conduct a physical exam, looking for signs of sinusitis. You doctor will ask if you have had persistent cold symptoms (lasting longer than five to seven days) and a poor response to over-the-counter decongestants, as both these things suggest a sinus infection.

    During the physical exam, your doctor will tap briskly on your cheeks and forehead to see if you have any tenderness overlying the sinuses. In addition, the doctor will check the back of your throat for post-nasal drip and redness.

    To confirm acute sinusitis, your doctor will shine a flashlight through your sinuses in a dark room (a procedure called trans-illumination), and may take an x-ray. Trans-illumination can identify sinusitis in some patients because blocked sinuses will be opaque to the light. However, this test is not useful for patients with chronic sinusitis, or other conditions that increase the thickness of the sinus bones. Four-view x-rays of the sinuses are also helpful.

    More highly technical diagnostic techniques are reserved for patients with chronic sinusitis, hospitalized patients, or those with complicated acute sinusitis. In chronic sinusitis, the physician must determine whether the patient has allergies or immune deficiency, and rule out the possibility that a tumor or growth called a granulomatous process is blocking the sinuses.

    Patients with suspected chronic sinusitis should always have computerized tomography, or CT scanning. This imaging technique produces precise images of structures within the skull, and will confirm or rule out the diagnosis of chronic sinusitis and pinpoint the affected sinuses. An ear, nose, and throat doctor may use nasal endoscopy in these patients. In this procedure, a flexible, lighted scope is inserted into the nose, and is passed down the nasal passages to the larynx. As the scope is inserted and then withdrawn, the doctor views the sinus openings, checks for blockage, and determines whether surgical widening of the ostia may be necessary. The patient receives local anesthesia to suppress the gag reflex, and may be sedated. During this procedure the doctor can also collect sinus secretions. Collection is important for complicated and chronic cases of sinusitis because it allows the doctor to determine the most appropriate antibiotic to give the patient for the infection.

    If you smoke, you should quit to protect yourself against sinusitis. Cigarette smoking impairs the function of the cilia, making the body less able to clear contaminants from the sinuses. Some smokers, for example, develop sinusitis every time they get a cold. Quitting allows the cilia to heal, and more effectively remove the bacteria, mucus, and foreign objects that can lead to sinusitis. In addition, if you stop smoking, you will no longer be introducing foreign material into the respiratory system that can cause inflammation of the nasal passages and interefere with normal muco-ciliary function. Vaccinations against certain bacteria, such as pneumoccal pneumonia, can help prevent sinusitis infections caused by those bacteria.

    Taking preventive measures when diving or traveling by air can prevent sinusitis caused by barotrauma. Holding the nose when jumping into water feet-first will prevent water from being forced into the nose, which can lead to sinusitis. When traveling in an airplane, chew gum or swallow frequently during takeoff and landing to equalize the pressure inside and outside the skull.

  • Prevention and Screening

    If you smoke, you should quit to protect yourself against sinusitis. Cigarette smoking impairs the function of the cilia, making the body less able to clear contaminants from the sinuses. Some smokers, for example, develop sinusitis every time they get a cold. Quitting allows the cilia to heal, and more effectively remove the bacteria, mucus, and foreign objects that can lead to sinusitis. In addition, if you stop smoking, you will no longer be introducing foreign material into the respiratory system that can cause inflammation of the nasal passages and interefere with normal muco-ciliary function. Vaccinations against certain bacteria, such as pneumoccal pneumonia, can help prevent sinusitis infections caused by those bacteria.

    Taking preventive measures when diving or traveling by air can prevent sinusitis caused by barotrauma. Holding the nose when jumping into water feet-first will prevent water from being forced into the nose, which can lead to sinusitis. When traveling in an airplane, chew gum or swallow frequently during takeoff and landing to equalize the pressure inside and outside the skull.

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