Учебники / Rhinosinusitis - A Guide for Diagnosis and Management 2008

Other Significant Patient History

Medications

Chronic use of nasal decongestants such as oxymetazoline (Afrin R ) can produce mucosal hypertrophy and rebound vascular dilation resulting in nasal obstruction. The resulting state is referred to as “rhinitis medicamentosa.” This scenario may mimic CRS and should be excluded in all patients. Loss of smell can be the result of adverse drug reactions to a variety of medications. Zinc-containing homeopathic nasal sprays have also been linked to smell dysfunction [39,40].

Past Medical History

Immune deficiency is perhaps an underreported factor in many chronic conditions. Careful evaluation of prior lower respiratory tract disease and childhood infections will help elucidate subtle abnormalities. Low immunoglobulin (Ig)G, IgA, and IgM titers were found in 18%, 17%, and 5% of refractory CRS patients, respectively. Common variable immunodeficiency and selective IgA have also been diagnosed in 10% and 6% of patients within this group [41].

Allergy has always been implicated in CRS, but there is little direct evidence to suggest a strong link in large epidemiologic studies [19]. Asthma and bronchospasm have a very close association with CRS, both with and without nasal polyps. The clinical course of either disease can be significantly altered by addressing each condition [7].

Cyclical changes with menstruation, hormonal abnormalities (such as hypothyroidism), and pregnancy can have an impact on sinonasal symptoms. Up to 20% of pregnant women will experience nasal obstruction [42]. The underlying pathophysiology of these changes has not been widely investigated.

Social History

Direct and second-hand cigarette smoke may have a deleterious effect on the respiratory mucosa in CRS and is currently under investigation [43]. Work environments can provide a significant exposure to occupational antigens and induce contact hypersensitivity or occupational rhinosinusitis. Home environments that are both damp and poorly ventilated may present high volumes of fungus; this may play a role in variety of chronic sinonasal conditions. Cocaine-induced rhinosinusitis should also elicited.

Family History

A strong family history, especially in nasal polyp patients, has provided speculation for a genetic predisposition to CRS. In the families of CRS patients, there is an

affected member in 14% to 53% of cases [44,45]. However, this possible genetic relationship has not been demonstrated in monozygotic twin studies [46].

Primary and Secondary Investigations

Nasal endoscopy and CT scans of paranasal sinuses form the foundation of CRS investigation

Endoscopy

Visual assessment of the nasal cavity is an invaluable tool in determining underlying pathological processes. Evaluation can be made with or without decongestion of the nasal mucosa. Oxymetazoline (Afrin R ) is commonly used. A local anesthetic spray is usually added but may have little added benefit as mucosal drag is thought to account for any discomfort [47–49]. Assessment can be performed with a 0◦ or 30◦ rigid endoscope (Fig. 4.11) or a flexible endoscope (Fig. 4.12).

Mucosal edema (see Fig. 4.4), polyps (see Fig. 4.2), discharge (Fig. 4.13; see also Fig. 4.9), and crusting (Fig. 4.14) form the cardinal endoscopic features of CRS. Mucosal edema and erythema can be somewhat subjective due to differences in lighting, endoscope optics, or camera quality, but are identifiable to an expe-

Fig. 4.11 Rigid endoscopy of the nose under topical anesthesia

Fig. 4.12 Flexible endoscopy of the nose under topical anesthesia

Fig. 4.13 Purulent discharge from the left middle meatus may accompany an acute exacerbation in CRS

rienced endoscopist. Positive endoscopic findings have a strong correlation with positive CT findings in CRS [50]. However, for negative endoscopic assessments only 71% of patients had negative CT scans in those with chronic nasal complaints without previous sinus operations [50]. Nasal endoscopy has a 67% to 78% negative predictive value (NPV) but offers an excellent positive predictive value [51].

axial slices and reconstruct images in the coronal plane. This has several advantages over traditional direct coronal assessment. Dental artefacts, from amalgam or other metal implants, can be avoided in the coronal reconstructions. Patients find a neutral neck position more comfortable, and spiral CT allows scanning of those with cervical arthropathy. Finally, helical or spiral axial imaging is very quick, and many centers may have “in-office” CT scanners dedicated to this process.

CT scans demonstrate mucosal thickening and secretions well (Fig. 4.16). The scans provide an excellent assessment for mucosal thickening but little insight into the nature of the histopathological correlate. Thus, CT scans bear little relevance to the state or severity of the CRS. Neither symptom scores or disease-specific quality-of-life measures correlate with the distribution or degree of CT opacification [52,53].

Even with some minor mucosal thickening taken to be within normal limits (Lund Mackay score below 4), the CT remains a highly sensitive test (94%), although the specificity remains low at 41% [54]. Incidental mucosal cysts can be present in up to 17% and mucosal thickening in 30% of the normal population [55]. Despite some shortcomings in specificity, CT remains an invaluable tool for diagnosing CRS. Symptom-based diagnosis alone is 89% sensitive but only 2% specific [56]. The positive predictive value of symptoms alone, as a diagnostic tool for CRS, is 73% for otolaryngologists and 58% for other physicians when compared to a diagnosis based on combined CT and clinical symptoms [56].

X-Ray

In general, plain sinus X-rays are insensitive and limited in their utility in modern CRS evaluation. False positives and false negatives are high with plain X-rays [57,58]. Underdiagnosis of disease in the anterior ethmoid sinuses and overdiagnosis of maxillary sinus disease are the most common findings in comparative studies [57,58]. Plain sinus radiographs (Water’s view) revealing mucous membrane thickening of 5 mm or complete opacification of one or more sinuses are no longer recommended in either the European[19] or American guidelines [11], except for research purposes.

Fig. 4.16 Typical appearances of mucosal thickening in CRS as seen by CT

Secondary Investigations

The majority of additional sinonasal investigations are of limited use in general clinical practice. Some of these tests for olfaction and the nasal airway have already been discussed. These tests are rarely performed routinely outside of speciality practice. It is important for the reader to be aware that objective measures of many of the sinonasal symptoms do exist. The majority of these are used for research, academic, and medicolegal purposes.

Mucociliary dysfunction is often discussed in the context of CRS. Mucociliary transport (MCT) times can be measured. The saccharine clearance time is an often quoted test of MCT. A standard saccharine sweetener tablet is placed 1 cm from the head of the inferior turbinate, and the elapsed time until perception of a sweet taste is recorded. Any time within 20 min is considered within normal limits. Ciliary beat frequency can also be measured under light microscopy after nasal mucosa brushings have been taken. Nasal nitric oxide levels also reflect mucosal inflammatory response and are extremely low in primary ciliary dysfunction. In addition, nasal inflammation can be measured by biopsy, electron microscopy, cytology, bacteriology, and nasal lavage. Peripheral blood leukocyte levels and C-reactive protein have little diagnostic value in the CRS patient.

Diagnostic Schemes

The following diagnostic schemes and clinical workups are currently endorsed by the European Academy of Allergology and Clinical Immunology (EAACI) [19]. These diagnostic pathways combine simple management with evaluation in the

Fig. 4.17 Diagnostic flow chart for adult CRS as recommended by the European position paper on CRS. Simplified management schemes have been provided. (Reproduced with permission from Fokkens W, Lund VJ, Mullol J. European position paper on rhinosinusitis and nasal polyps. Rhinology Journal, June 2007 [19].)