Excerpt from Rhinoscleroma

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Background

Rhinoscleroma is a chronic granulomatous condition of the nose and other structures of the upper respiratory tract. Rhinoscleroma is a result of infection by the bacterium Klebsiella rhinoscleromatis. The Polish surgeon Johann von Mikulich in Wroclaw described the histologic features in 1877; von Frisch identified the organism in 1882. In 1932, Belinov proposed the use of the term scleroma respiratorium because the pathologic process in rhinosclerosis may involve not only the upper airways but also the lower airways. In 1961, Steffen and Smith demonstrated that K rhinoscleromatis conformed to Koch's postulates and that it was an etiologic factor in the inflammatory changes typical of scleroma.

The eMedicine article Klebsiella Infections may be of interest, as may the Medscape Pediatric Dermatology Resource Center.

Pathophysiology

Rhinoscleroma is contracted by means of the direct inhalation of droplets or contaminated material. The disease probably begins in areas of epithelial transition such as the vestibule of the nose, the subglottic area of the larynx, or the area between the nasopharynx and oropharynx. Cellular immunity is impaired in patients with rhinoscleroma; however, their humoral immunity is preserved.

The CD4/CD8 cell ratio in the lesion is altered with decreased levels of CD4 lymphocytes; this change possibly induces a diminished T-cell response. Macrophages are not fully activated. Mucopolysaccharides in the bacterial capsule probably contribute to the inhibition of phagocytosis. Otherwise, patients are immunocompetent in every regard except for the ineffective phagocytosis of the organism by the Mikulicz cells.

Rhinoscleroma usually affects the nasal cavity, but lesions associated with rhinoscleroma may also affect the larynx; nasopharynx; oral cavity; paranasal sinuses; or soft tissues of the lips, nose, trachea, and bronchi.

Although it is usually caused by K pneumoniae subsp rhinoscleromatis, K pneumoniae subsp ozaenae was isolated from the pharynx of a woman with laryngeal scleroma.¹

A Mexican study showed that DQA1*03011-DQB1*0301 haplotype is a strong risk factor for its development.²

Frequency

It is endemic to regions of Africa (Egypt, tropical areas), Southeast Asia, Mexico, Central and South America, and Central and Eastern Europe, but it has been infrequent in the United States. Five percent of all cases occur in Africa. However, with current trends in migration, the incidence of rhinoscleroma may be on the rise.³ The incidence of rhinoscleroma appears to be increasing in the United States. Rare sporadic cases occur in the United States, usually in immigrant populations arriving from the countries in which the disease is endemic.

Mortality/Morbidity

• Rhinoscleroma is rarely lethal, unless it causes airway obstruction.
• The diagnosis may elude the clinician for years, and this delay can substantially increase the rate or severity of resultant morbidity.

Race

Patients of all races can be affected.

Sex

Rhinoscleroma tends to affect females somewhat more often than it does males.

Age

Typically, rhinoscleroma appears in patients aged 10-30 years.

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