Sinusitis classification

1. By location
There are several paired paranasal sinuses, including the frontal, ethmoid, maxillary and sphenoid sinuses. The ethmoid sinuses can also be further broken down into anterior and posterior, the division of which is defined as the basal lamella of the middle turbinate. In addition to the acuity of disease, discussed below, sinusitis can be classified by the sinus cavity which it affects:
 * Maxillary sinusitis - can cause pain or pressure in the maxillary (cheek) area (e.g., toothache, headache) (J01.0/J32.0)


 * Frontal sinusitis - can cause pain or pressure in the frontal sinus cavity (located behind/above eyes), headache (J01.1/J32.1)


 * Ethmoid sinusitis - can cause pain or pressure pain between and/or behind eyes, headache (J01.2/J32.2)


 * Sphenoid sinusitis - can cause pain or pressure behind the eyes, but often refers to the vertex of the head(J01.3/J32.3)

Recent theories of sinusitis indicate that it often occurs as part of a spectrum of diseases that affect the respiratory tract (i.e. - the "one airway" theory) and is often linked to asthma. All forms of sinusitis may either result in, or be a part of, a generalized inflammation of the airway so other airway symptoms such as cough may be associated with it.

2. By duration
Sinusitis can be acute (going on less than four weeks), subacute (4-12 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 sinusitis
Acute sinusitis is usually precipitated by an earlier upper respiratory tract infection, generally of viral origin. Virally damaged surface tissues are then colonized by bacteria, most commonly Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis and Staphylococcus aureus. Other bacterial pathogens include other streptococci species, anaerobic bacteria and, less commonly, gram negative bacteria. Another possible cause of sinusitis can be dental problems that affect the maxillary sinus. 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.

Chronic sinusitis
Chronic sinusitis is a complicated spectrum of diseases that share chronic inflammation of the sinuses in common. The causes are multifactorial and may include allergy, environmental factors such as dust or pollution, bacterial infection, and/or fungus (either allergic, infective or reactive). Non allergic factors such as Vasomotor rhinitis can also cause chronic sinus problems.

Symptoms include: Nasal congestion; facial pain; headache; fever; general malaise; thick green or yellow discharge; feeling of facial 'fullness' worsening on bending over; aching teeth.

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.

Attempts have been made to provide a more consistent nomenclature for subtypes of chronic sinusitis. A task force for the American Academy of Otolaryngology - Head and Neck Surgery / Foundation along with the Sinus and Allergy Health Partnership broke Chronic Sinusitis into two main divisions, Chronic Sinusitis without polyps and Chronic Sinusitis with polyps (also often referred to as Chronic Hyperplastic Sinusitis). Recent studies which have sought to further determine and characterize a common pathologic progression of disease have resulted in an expansion of proposed subtypes. Many patients have demonstrated the presence of eosinophils in the mucous lining of the nose and paranasal sinuses. As such the name Eosinophilic Mucin RhinoSinusitis (EMRS) has come into being. Cases of EMRS may be related to an allergic response, but allergy is often not documentable, resulting in further subcategorization of allergic and non-allergic EMRS.

A more recent, and still debated, development in chronic sinusitis is the role that fungus may play. Fungus can be found in the nasal cavities and sinuses of most patients with sinusitis, but can also be found in healthy people as well. It remains unclear if fungus is a definite factor in the development of chronic sinusitis and if it is, what the difference may be between those who develop the disease and those who do not.