Epidemology and Diagnosis of Sinusitis

EPIDEMIOLOGY

Epidemiology of Bacterial Sinusitis:

• Viral bacterial sinusitis develops in 90% of patients with a viral upper respiratory tract infection (“cold”).
• Bacterial sinusitis has a seasonal pattern, associated with “cold” epidemics that occur in the autumn, winter, and spring, and are less common during the summer. Typically, rhinoviruses occur in early autumn and late spring, while respiratory syncytial virus, influenza virus, and coronavirus strike in early spring and winter.
• Acute bacterial sinusitis occurs in 0.5% to 2% of individuals with viral infections (colds) (about 20 million Americans yearly).
• The economic impact of rhinosinusitis is considerable.

Viral upper respiratory infection can lead to acute bacterial infection (where aerobes predominate) ultimately to chronic one (where anaerobes predominate).

DIAGNOSIS AND SIGNS AND SYMPTOMS 

Bacterial sinusitis can be classified chronologically into 5 categories:

Acute: 10 days to 4 weeks
Recurrent acute: 4 episodes of acute per year
Subacute: 4–12 weeks
Chronic: > 12 weeks
Acute exacerbation of chronic: Worsening infection, returning to chronic baseline

Definitions of bacterial sinusitis
Definitions of bacterial sinusitis	Length of infection
Acute	10 days to 4 weeks
Recurrent acute	³ 4 episodes of acute per year
Subacute	4–12 weeks
Chronic	> 12 weeks
Acute exacerbation of chronic	Worsening infection, returning to chronic baseline

Clinical Diagnosis of Bacterial Sinusitis:

Establishing a diagnosis may be difficult because differentiation must be made between allergic rhinitis and other causes of head or facial pain, asthma, and dental disorders. An allergic etiology can be confirmed by establishing a history of nasal symptoms and a history of allergy.

 Medical history, symptoms, and findings suggestive of allergy
History
Personal	Past episodes of allergy that responded to antihistamines and anti-inflammatory agents
	Asthma
	Skin and food allergies
Family	Allergies in close relatives
Symptoms	Itching of ears, nose, and eyes
	Paroxysms of sneezing exacerbated by external factors (e.g., animal exposure, dust)
Findings	Pale, swollen, purple inferior turbinate
	Evidence of atopy such as eczema, urticaria, or asthma
	Allergic nasal crease

The most predictive clinical signs and symptoms of bacterial sinusitis in adults and children are pressure and pain, thick nasal discharge, fever and cough or irritability. Allergy is associated with itchy, runny nose, thin watery nasal discharge, history of seasonal allergy and other allergic symptoms.

Practical Criteria:

Practical criteria for the diagnosis of bacterial sinusitis are based on either major or minor symptoms, signs, and findings. The major ones are facial pain, congestion, nasal discharge, fever (for acute sinusitis), and purulence. Minor criteria are headache, halitosis, fatigue, dental pain, and cough. The presence of bacterial sinusitis is suspected when at least two major or one major and two minor criteria are found.

Major and minor criteria of bacterial sinusitis*
Major criteria	Minor criteria
Facial pain/pressure (requires a second major criterion to constitute a suggestive history)	Headache
Facial congestion/fullness	Fever (for subacute and chronic sinusitis)
Nasal congestion/obstruction	Halitosis
Nasal discharge/purulence/discoloured postnasal drainage	Fatigue
Hyposmia/anosmia	Dental pain
Fever (for acute sinusitis; requires a second major criterion to constitute a strong history)	Cough
Purulence on intranasal examination	Ear pain/pressure/fullness
*Diagnosis of bacterial sinusitis based on major and minor criteria. Strong history requires the presence of two major criteria or one major and two or more minor criteria. Suggestive history requires the presence of one major criterion or two or more minor criteria.

• The most common presentation in children is a persistent (and unimproved) nasal discharge or cough (or both) lasting longer than 10 days. A 10-day period separates simple viral upper respiratory tract infection (URTI) from bacterial sinusitis because most uncomplicated viral URTIs last between 5 and 7 days—by day 10 most patients are improving.

• The quality of the nasal discharge varies, and it can be thin or thick, clear mucoid, or purulent.
• Although children cough during the day, this is generally worse at night.

Enclosed are the symptoms that differentiate bacterial sinusitis from allergy:

Sinus infection versus allergy
Infection	Allergy
Nasal obstruction and/or congestion	Nasal obstruction and/or congestion
Pressure with pain	Itchy, runny nose
Thick nasal discharge	Paroxysmal sneezing
Toothache	Thin, watery nasal discharge
Fever	History of sinusitis during allergy season
Cough or irritability	Other allergic signs or symptoms

The symptoms and signs of acute bacterial sinusitis can be divided into non-severe ( rhinorrhea, cough, headache, facial pain. and low grade fever) and severe forms (Purulence, periorbital edema, and high fever). The severe form carries a higher risk of complications and mandates earlier use of antimicrobial therapy. The combination of high fever and purulent nasal discharge lasting for at least 3 to 4 days points to a bacterial infection of the sinuses.

Symptoms and signs of bacterial sinusitis
Non-severe acute sinusitis	Severe acute sinusitis
Rhinorrhea (of any quality)	Purulent (thick, colored, opaque) rhinorrhea
Nasal congestion	Nasal congestion
Cough	Facial pain or headache
Headache, facial pain, and irritability (variable)	Periorbital edema (variable)
Low-grade or no fever	High fever (temperature ³ 39°C)

In children with subacute or chronic bacterial sinusitis the symptoms are protracted. Fever is rare, the cough and nasal congestion persist, and a sore throat (as a result of mouth breathing) is common.
The location of the facial pain can point to which of the sinuses is involved. Maxillary bacterial sinusitis is often associated with pain in the cheeks, frontal with the forehead, ethmoid with medial canthus, and sphenoid with occipital pain. Other suggestive factors are action or position that makes the sinus worse or better, and clues that suggest the presence of chronic infection.

Signs of Sinus Infection That Can Be Observed by Physical Examination:

• Mucopurulent nasal or posterior pharyngeal discharge.
• Erythematous nasal mucosa that may be pale and boggy.
• Signs of infection in the throat that can be associated with malodorous breath.
• Acute otitis media can be present in association with acute bacterial sinusitis, and otitis media with effusion with chronic bacterial sinusitis.
• Cervical lymphadenitis may be present but rare.
• Facial tenderness is inconsistent and nonspecific.
• Periorbital edema with skin discoloration can be present, especially in children with ethmoid sinusitis.
• Disease in the upper molar teeth may be the source of maxillary sinusitis.
Further work-up and consideration for hospitalization include suspicion of nosocomial sinusitis (recent intubation, feeding or suction device), patients who are immunocompromised, possible meningitis or other intracranial complications, or frontal or sphenoid sinusitis.

Clues for the sinuses involved can be ascertained from the location of the pain and tenderness:

The clinical picture of acute bacterial sinusitis Ethmoid sinusitis Frontal sinusitis Maxillary sinusitis Sphenoid sinusitis Common complaints Common complaints Nasal congestion Severe frontal headaches Pain over the cheekbone on one side of the face Deep headache with multiple foci (occipital with frontal, temporal, retro-orbital, or vertex) Purulent rhinorrhea Fever (typical but not always present) Toothache Fever of unknown origin Inner canthal pain or pressure Periorbital or supraorbital pain Periorbital headache Temporal headache Temporal headache Other suggestive factors Other suggestive factors Fever Severe frontal headache associated with tenderness over the frontal sinus on percussion or palpation Tenderness over the maxillary sinus Nasal obstruction Mucosal edema Tenderness at the inner canthal area Hypermia Purulent drainage in the middle meatus Positive PFR findings Additional considerations Additional considerations Involvement of other sinuses often combined with acute maxillary sinusitis Acute frontal sinusitis constitutes a medical emergency; surgical referral is indicated Extreme pain may indicate need for surgical referral for decompression Acute sphenoid sinusitis constitutes a medical emergency; surgical referral is indicated Pus, erythema, and edema seen only endoscopically Adolescent males particularly at risk for intracranial complications May be difficult to diagnose by PFR studies; basal view may be helpful Complications: meningitis, epidural abscess, subdural empyema, brain abscesses, and visual loss (uncommon but not rare) Warning signs of impending CNS complications: diplopia, visual changes, and paresthesia involving the second branch of the fifth cranial nerve Makes symptoms worse Makes symptoms worse Coughing Lying supine Maintaining the head in an upright position Lying supine Straining Pressing thumb up against floor of frontal sinus (medial, superior to eye) Bending forward or Valsalva’s maneuver Lying supine Makes symptoms better Makes symptoms better Maintaining the head in an upright position Maintaining the head in an upright position Lying supine Maintaining the head in an upright position Clues to chronic bacterial sinusitis Clues to chronic bacterial sinusitis Triad of nasal obstruction, chronic rhinorrhea, or postnasal discharge, and low-grade discomfort History of ostial trauma leading to long-standing inflammation Malar discomfort Low-grade, diffuse headache (common but not always present) Patient pinching the bridge of the nose to demonstrate the area of discomfort Persistent, low-grade frontal headache Symptoms worse with upper respiratory tract infections or exacerbation of allergy Symptoms worse in late morning and aggravated by wearing eyeglasses Persistent sinus opacification on PFR Discomfort typically worse throughout the course of the day Recurrent sore throat and halitosis Nocturnal cough Recurrent secondary maxillary or frontal sinusitis CNS = central nervous system; PFR = plain film radiography.

Required patient assessments, especially when complications are suspected are:

1. A complete head and neck examination (including the orbit, extra­ ocular motility, the response of the pupils, vision, and cranial nerve function)
2.Palpation and/or percussion (over the frontal sinuses, cheeks [maxillary sinuses], and medial orbit [ethmoid sinuses])
3. Bending the head forward (when sitting) and holding it at knee level for 45–60 s; this can elicit a sensation of fullness and pain at the involved sites
4. Assessment of nasopharynx for postnasal drip and obstruction caused by adenoid hypertrophy, choanal atresia, malignancy, polyps, and septal deviation
5. Nose examination, especially in chronic infection; anterior rhinoscopy is performed with a good light source after application of a topical decongestant; the presence of edema, erythema, crusting, or purulent secretion should be noted
6. Endoscopy may localize the pus within the nasal cavity and direct the examiner to the involved sinus(es); bacterial cultures can also be obtain; however, the specimens obtained may contain nasal mucosal flora.

DIAGNOSITIC TESTS

These include transillumination, mucociliary clearance testing, sinus aspiration, and rhinomanometry.

Transillumination

Transillumination is infrequently utilized because the findings do not always correlate with the disorder. The poor reproducibility between observers limits the use of this method.

Guidelines for performing transillumination

• Use a completely dark room, after the examiner’s eyes have adapted to darkness.

• Place a strong source of light (preferably a transilluminator) over the suspected sinus to see whether light can be transmitted.

• Examine the maxillary sinus by shining light through the sinus from the infraorbital area and observe its transmission through the hard plate.

• Test the frontal sinus by shining the light superiorly through the supraorbital ridge and observe transmission through the forehead; the bilateral symmetry of the flash needs to be evaluated.

Transillumination of the maxillary sinus

Sinus Aspiration and Endoscopy:

The indications for maxillary sinus aspiration are failure to improve on antimicrobial therapy, severe facial pain, orbital or intracranial complications, and in the immunocompromised host. Aspiration of the sinus for culture is the method of choice for determining the microbiology. Culture of nasal pus or of sinus exudate obtained by rinsing through the sinus ostium can give unreliable information because of contamination by the resident bacterial nasal flora. Collection of specimen for culture could also be attempted by using endoscopy, but there is the risk of contamination by nasal flora.

Needle aspiration of the maxillary sinus

Laboratory Assessment of Aspirated Material:

• Gram stain and leukocyte count.

• Aerobic and anaerobic bacterial, fungal, and mycobacterial cultures, using the proper transport systems.

• Viral cultures are done in selected cases and for research purposes.

• Quantitative bacterial cultures are useful. The recovery of organisms in a concentration of at least 10000/ml is considered to represent true infection rather than contamination.

• Gram and other special stains. Observing at least a single organism per high power field or gram stain of an aspirate correlates with the isolation of bacteria in a density > 100000 cfu/ml.

• Biopsy of the sinus mucosa provides greater accuracy in establishing the diagnosis of infection.

LABORATORY TESTING

Laboratory Tests for Patients with Recurrent Acute or Chronic Bacterial Sinusitis Include:


• Erythrocyte sedimentation rate (ESR). An elevated ESR may signify a systemic illness or osteomyelitis complicated sinusitis.
• Complete blood count.
• Serum immunoglobulin (to exclude underlying immunodeficiency).
• Sweat chloride evaluation (to exclude cystic fibrosis).
• Testing for human immunodeficiency virus (HIV) infection.
• Allergy testing is carried out when indicated.