SINUS INFECTION

Sinus infection, or more generally sinusitis, is an inflammation of the paranasal sinuses, which may or may not be as a result of infection, from bacterial, fungal, viral, allergic or autoimmune issues. Sinusitus can exhibit itself in many ways. It can cause pain or pressure in the cheek area, between the eyes, or behind the eyes. This may result in such symptons as headache or toothache.

Sinusitis can be acute (going on less than four weeks), subacute (4 to 12 weeks) or chronic (going on for 12 weeks or more). All three types of sinusitis have similar symptoms, and are thus often difficult to distinguish.

ACUTE SINUSITUS

Acute sinusitis is usually precipitated by an earlier upper respiratory tract infection, generally of viral origin. If the infection is of bacterial origin, the most common 3 causitive agents are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis respectively. Haemophilus influenzae in the past was the most common bacterial agent to cause sinus infections. However since the introduction of Hib vaccine there has been a dramatic decrease in H.Influenza type B infections and usally the non-typable strains of H.influenza are seen now in the clinical setting. Other bacterial pathogens include other Staphylococcus aureus and other streptococci species, anaerobic bacteria and, less commonly, gram negative bacteria. Viral sinusitis typically lasts for 7 to 10 days, whereas bacterial sinusitis is more persistent. Approximately 0.5% to 2% of viral sinusitis extends into bacterial sinusitis. One hypothesis postulates that the bacterial infection begins with nose blowing.

Acute episodes of sinusitis can also result from fungal invasion. These infections are most often seen in patients with diabetes or other immune deficiencies (such as AIDS or transplant patients on anti-rejection medications) and can be life threatening. In type I diabetes, ketoacidosis causes sinusitis by Mucormycosis

Chemical irritation can also trigger sinusitis. Commonly from cigarettes and chlorine fume. Rarely, it may be caused by a tooth infection.

CHRONIC SINUSITUS

Chronic sinusitis is a complicated spectrum of diseases that share chronic inflammation of the sinuses in common. It is divided into cases with polyps and cases without, and the former is sometimes called chronic hyperplastic sinusitis. The causes are poorly understood and may include allergy, environmental factors such as dust or pollution, bacterial infection, or fungus (either allergic, infective, or reactive). Non allergic factors such as vasomotor rhinitis can also cause chronic sinus problems. Abnormally narrow sinus passages, which can impede drainage from the sinus cavities could also be a factor. A combination of anaerobic and aerobic bacteria are observed, including Staphylococcus aureus and coagulase-negative Staphylococci. Typically antibiotics provide only a temporary benefit, although mechanisms involving hyperresponsiveness to bacteria have been proposed for sinusitis with polyps.

Most symptoms include: nasal congestion; facial pain; headache; fever; general malaise; thick green or yellow discharge; vertigo or lightheadedness; blurred vision, feeling of facial 'fullness' or 'tightness' which worsens on bending over; aching teeth, and halitosis. Very rarely, chronic sinusitis can lead to anosmia, the inability to smell or detect odors. In a small number of cases, chronic maxillary sinusitis can also be brought on by the spreading of bacteria from a dental infection.

SYMPTOMS

Headache/facial pain or pressure of a dull, constant, or aching sort over the affected sinuses can be seen with either acute or chronic stages of sinusitis. This pain is typically localized to the involved sinus and may worsen when the affected person bends over or when in the supine position.

Acute and chronic sinusitis may be accompanied by thick purulent nasal discharge (usually green in colour and with or without blood) and localized headache (toothache) are present and it is these symptoms that can differentiate sinus related (or rhinogenic) headache from other headache phenomena such as tension headache and migraine headache.

Recent studies suggest that up to 90% of "sinus headaches" are actually migraines. The confusion occurs in part because migraine involves activation of the trigeminal nerves which innervate both the sinus region but also the meninges which surround the brain. As a result, direct determination of the site of pain origination can be confused on a cortical level. Additionally, nasal congestion is not an uncommon result of migraine headaches, due to the autonomic nervous stimulation that can also result in tearing (lacrimation) and a runny nose (rhinorrhea). A study found that patients with "sinus headache" respond to triptan migraine medications, and state dissatisfaction with their treatment when they are treated with decongestants or antibiotics.