Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (576 page)

   
Renal disease
: Common, although clinically important involvement is occasional. Glomerular involvement is rare. Most patients remain asymptomatic, but nephrolithiasis (1–14%), nephrocalcinosis (observed in half of patients with renal insufficiency), and polyuria are potential complications. Hypercalciuria and hypercalcemia due to hyperabsorption of dietary calcium are most often responsible for renal involvement, but granulomatous interstitial nephritis, glomerular disease, obstructive uropathy, and rarely end-stage renal disease may occur.

   Diagnostic and Laboratory Findings

   Diagnosis requires biopsy in most cases. Endobronchial biopsy via bronchoscopy is often done.

   Routine laboratory evaluation is often unrevealing, but possible abnormalities include hypercalcemia, hypercalciuria, and elevated alkaline phosphatase and angiotensin-converting enzyme (ACE) levels.

   
Kveim-Siltzbach test:
This is a skin test specially designed for the diagnosis of sarcoidosis. It involves intradermal injection of sarcoid tissue preparation resulting in a specific localized granulomatous response (firm red papules) in patients with sarcoidosis. This test is poorly standardized and rarely used.

   Pulmonary function test: Spirometry and diffusing capacity of the lung for the carbon monoxide (DLCO) are commonly used.

   Serologic tests: A variety of laboratory and biologic markers are available such as ACE, lysozyme, neopterin, soluble IL-2 receptor, soluble intercellular adhesion molecules (ICAM-1, IFN-8), or in bronchoalveolar lavage (BAL) fluid, such as high lymphocytes, activation of marker expression on T cells, CD4/CD8 ratio, macrophages, TNF-alpha release, collagen III peptide, vitronectin, fibronectin, and hyaluronan. None of the mentioned markers are clinically recommended as routine assessment, except for serum ACE.

   Serum ACE is elevated in 40% of patients who have clinically active disease. It has limited value in the diagnosis, but useful in monitoring the course of disease and treatment.

Suggested Reading

Dastoori M. et al. Sarcoidosis—a clinically oriented review.
J Oral Pathol Med.
2013;42:281–289.

UPPER AIRWAY COUGH SYNDROME

   Definition

Upper airway cough syndrome (UACS) is the newly recommended term to replace postnasal drip syndrome, referring to cough associated with upper airway conditions, because it is unclear whether the mechanism of cough is postnasal drip, direct irritation, or inflammation of the cough receptors in the upper airway. Postnasal drip is the drainage of secretions from the nose or paranasal sinuses into the pharynx. UACS, which is secondary to a variety of rhinosinus conditions, is the most common cause of chronic cough. It includes a variety of diseases: allergic rhinitis, perennial nonallergic rhinitis, nonallergic rhinitis with eosinophilia (NARES), bacterial sinusitis, and allergic fungal sinusitis, rhinitis due to anatomic abnormalities, rhinitis due to physical or chemical irritants, and occupational rhinitis.

   Who Should Be Suspected?

Clinically, the diagnosis depends on the reporting of the patient of a sensation of having something drip down into the throat, nasal discharge, or frequent throat clearing. The presence of mucoid, mucopurulent secretions, or cobblestoning of the mucosa during nasopharyngeal or oropharyngeal examination is also suggestive of UACS. It is the most common cause of the chronic condition.

   Diagnostic Findings