Laboratory Studies
See the list below:
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Complete blood cell count with differential if an infection is suspected
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Sputum cultures and sensitivities for bacteria, fungi, and viruses
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Swab of the laryngeal mucosa, culture and sensitivities for bacteria, fungi, and viruses
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Serologic markers for autoimmune disorders
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Studies for tuberculosis and syphilis when such conditions are being considered
Imaging Studies
See the list below:
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A lateral plain neck radiograph can help visualization of supraglottic and retropharyngeal swelling and soft tissue density in the subglottic airway. It is especially helpful in the emergency department.
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Chest radiograph
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CT scanning and MRI better define soft tissue alterations and provide the best information regarding the structure of the larynx.
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Barium swallow study, double-contrast upper GI series, and manometry are often used to evaluate otolaryngologic manifestations of GERD.
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A videostrobe is probably the single most important study after excluding a tumor. It provides significant information regarding vocal fold vibration, which can be recorded on a monitor.
Other Tests
See the list below:
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Skin tests if allergies are suspected
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Twenty-four–hour pH monitoring if GERD is in the differential diagnosis
Procedures
The larynx can be directly examined with a flexible fiberoptic nasopharyngolaryngoscope. Direct laryngoscopy with a rigid laryngoscope (under general anesthesia) may be required for a detailed laryngeal inspection and may help obtain tissue for biopsy, cultures, and smears to identify the presence of organisms. Undertake this examination when noninvasive studies fail.
Accomplish a thorough evaluation of the aerodigestive tract, including bronchoscopy and esophagoscopy, when indicated. Stroboscopic examination may help to differentiate mucosal stiffness secondary to epithelial hyperplasia that may be caused by chronic inflammation. Endoscopic removal of polyps and lysis of adhesions can be surgically accomplished.
A study by Witt et al suggested that hue and texture analysis of laryngoscopic images can be used to diagnose laryngopharyngeal reflux (LPR) in patients with chronic laryngitis. The study, which included 20 patients with LPR and 42 controls, used hue calculation and two-dimensional Gabor filtering to evaluate color and texture features of the images, with 80.5% classification accuracy found when hue and texture were assessed together. [10]
Histologic Findings
Frequently, the histologic examination may not distinguish the different possibilities. For example, reflux laryngitis and pachydermia associated with long-term smoking provide a similar clinical picture. In both cases, acute and chronic inflammatory cellular infiltrates predominate, with or without epithelial hyperplasia. Different patterns of chronic tissue response can result from the following insults:
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Infiltrative disorders (eg, amyloidosis). Lipoid proteinosis of the larynx, represented by hyaline deposits, may mimic singer's nodules or chronic laryngitis. [11]
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Chronic granulomatous diseases (eg, sarcoidosis, tuberculosis, fungal laryngitis)
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Chronic nonspecific inflammation (eg, bacterial laryngitis, laryngitis sicca)
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Proliferative processes involving the epithelial layer, hyperkeratosis, dyskeratosis, parakeratosis, acanthosis, and cellular atypia can cause chronic tissue responses. The most extreme clinical picture is laryngeal ulceration and presence of granuloma.
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Illustration of the larynx.
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Illustration of the glottic and supraglottic larynx.
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Illustration of the larynx, posterior view.
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Illustration of the larynx, nasopharyngeal view.
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Illustration of the intrinsic muscles of the larynx, sagittal view.
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Illustration of the intrinsic muscles of the larynx, sagittal view.
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Illustration of the extrinsic muscle insertions of the larynx.
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Illustration of the intrinsic muscles of the larynx, superior view.
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Illustration of the intrinsic muscles of the larynx.
