Chronic Sinusitis

Etiology

As stated in the acute sinusitis chapter, viruses and bacteria are the most common etiologies for sinusitis. Streptococcus, pneumococcus, Hemophilus, and Moraxella are the most common bacterial causes. Chronic sinusitis is multifactorial in nature and can include infectious, inflammatory, or structural factors. Thus, other etiologies such as allergic rhinitis (dust mites, molds), exposures (airborne irritants, cigarette smoke or other toxins), structural causes (nasal polyps, deviated nasal septum), ciliary dysfunction, immunodeficiencies, and fungal infections should be considered. Otitis media, asthma, AIDS, and cystic fibrosis, are other medical conditions that can be associated with chronic rhinosinusitis.[3][4]

Epidemiology

When the inflammatory process involves the paranasal sinus, it is sinusitis. It can often involve accompanying nasal airway inflammation, and when it involves both, this is then called rhinosinusitis. Chronic rhinosinusitis is one of the most common chronic conditions. It is prevalent among all age groups and is the fifth most common reason for an antibiotic prescription.[5][6][7]

Pathophysiology

There are four paired sinus cavities: the ethmoid, sphenoid, frontal, and maxillary sinus cavities. These paired cavities allow air to be filtered during inhalation. For the antigens to be filtered and expelled, sinuses need to drain. Chronic inflammation can cause obstruction to the nasal passage, hinder drainage, and lead to lower oxygen tension. This creates foci for bacteria to build up. Ciliary dysfunction or structural abnormalities can further exacerbate this process. [8]

Histopathology

Biopsy samples will usually reveal thickened basement membrane, goblet cell hyperplasia, atypical gland architecture and infiltration with monocytes. Sometimes one may also see neutrophils and eosinophils in chronic cases.

History and Physical

The three cardinal symptoms of sinusitis are:

1) Purulent drainage: green or yellow nasal discharge2) Facial/dental pain: aching, fullness or pressure-like pain 3) Nasal obstruction: this can cause difficulty breathing from one or both nasal passages or cause mouth breathing

Other symptoms of chronic sinusitis include hyposmia (decreased sense of smell), headache, ear pain, halitosis (bad breath), dental pain, cough, or fatigue. Fever only has a 50% sensitivity but is an important factor in determining the severity of sinusitis. The duration of symptoms is the key factor in diagnosing chronic sinusitis. Symptoms should occur for more than 12 weeks. Recurrent sinusitis occurs with four episodes of sinusitis within one year.

Evaluation

Chronic sinusitis is diagnosed when at least two of the following four symptoms are present and occur for more than 12 weeks: (1) purulent drainage, (2) facial and/or dental pain, (3) nasal obstruction, (4) hyposmia. The Infectious Disease Society of America (IDSA) defines sinusitis as two of the following major clinical symptoms: purulent nasal discharge, nasal congestion or obstruction, facial congestion or fullness, facial pain or pressure, hyposmia, anosmia. Alternatively, ISDA defines sinusitis as one of the aforementioned major symptoms plus two or more minor criteria such as a headache, ear pain, pressure, or fullness, halitosis or bad breath, dental pain, cough, or fatigue.

During the history and physical examination evaluation, practitioners should examine the patient for other causes such as nasal polyps. Chronic sinusitis is less common than acute sinusitis. Acute sinusitis can last up to four weeks. However, chronic sinusitis lasts twelve weeks or longer.  Practitioners can seek other non-infectious etiologies such as gastric gastroesophageal reflux, anatomical variations or structural problems of the nasal cavity, history of immunodeficiencies, history of ciliary dysfunction, and history consistent fungal infections.

Either CT or nasal endoscopy, confirming the presence of inflammation must be documented to confirm the diagnosis of chronic sinusitis. CT is more sensitive but also more expensive than nasal endoscopy. Anterior rhinoscopy has limited visualization and has lower sensitivity and should not be used to confirm chronic sinusitis. There is a large role for shared decision-making when discussing which option to choose. Cone-beam CT scanning has become a point-of-care alternative imaging study.

Routine lab work is not necessary to diagnose chronic rhinosinusitis. Cultures are not necessary but can be helpful in treatment. If a practitioner does a nasal endoscopy, the sinus cultures should be done and are much more accurate than nasopharyngeal swabs. This can assist in providing targeted antibiotic therapy.

Allergy testing, in general, is helpful and should be considered as an option.[9][10][11]

Treatment / Management

There is no consensus on an approach to the management of chronic sinusitis. The treatment should focus on modulating triggers, reducing inflammation, and eradicating the infection.[12][5](B2)

Trigger Reduction

• Allergy testing can help identify environmental triggers that patients should avoid.

Medical Management

• Nasal steroids should be used with or without nasal saline irrigation. The treatment should last at least eight to 12 weeks with proper usage.
• Nasal saline irrigation is inferior to nasal steroids. However,  nasal saline irrigation can serve as a useful adjunct. High volume nasal saline irrigation was found to be more effective than low-volume nasal spray techniques.
• Antihistamines should only be used if an allergic component is suspected.
• Decongestants can be used for symptomatic relief, but evidence for supporting their use in chronic sinusitis is lacking.
• Antibiotics can be given for an extended period of three weeks. However, there is no consensus on their routine use in chronic sinusitis, nor is their consensus on antibiotic selection.
• Anti-fungal empiric therapy should not be given.
• Oral steroids can be used. However, their use is not routinely indicated. Comments regarding their use are given below.  Should oral steroids be used, physicians should engage in shared decision-making with patients.

Nasal Polyps

• Chronic sinusitis with polyps should be treated with topical nasal steroids. If severe or unresponsive to therapy after 12 weeks, a short course of oral steroids can be considered.
• Leukotriene antagonists can be considered.

Surgical Management

• Functional endoscopic sinus surgery can be considered for patients who fail medical management. In more complicated cases, it can serve as an adjunct to medical management. The goal of this surgery is to relieve obstructions, restore drainage and mucociliary clearance, and to ventilate the sinuses.

If an underlying medical condition is found, then therapy should target the underlying condition. This could include surgical and medical approaches to fungal sinusitis or Intravenous immunoglobulin for immunodeficiencies. Management for both of these conditions is beyond the scope of this chapter.

Other associated and predisposing medical conditions should also be treated. These include asthma, otitis media, and cystic fibrosis.

Differential Diagnosis

• Asthma
• Sinus tumors
• Oral cavity infections
• Nasal and sinus papillomas

Complications

• Laryngitis
• Dacryocystitis 
• Orbital cellulitis/abscess
• Cavernous sinus thrombosis
• Meningitis, subdural abscess, brain abscess
• Frontal bone osteomyelitis