Rhinoscleroma

Rhinoscleroma is endemic in isolated tropical areas of Latin America, Africa, and Asia, where crowding and poor hygiene are prevalent. It is spread by direct or indirect contact of nasal secretion. Adult patients of either gender are affected equally. Granulomas originate in the nose, and in the advanced cases can spread to the nasopharynx, larynx, pharynx, trachea, and bronchi. The early stage, rhinoscleroma, begins as nonspecific rhinorrhea with a purulent discharge and mucous membrane hypertrophy. Later granulomatous nodules and friable masses infiltrate the nasal cavity, the skin of the nose, and upper lip, eventually obstructing the nose, deforming and destroying the surrounding tissues.

Rhinoscleroma is a chronic inflammatory disease of the nasal and oral mucosa caused by the Gram-negative bacillus Klebsiella rhinoscleromatis.898 In advanced cases it may spread to involve the larynx, trachea, bronchi, and lips.899 Rhinoscleroma is endemic in parts of Africa, Asia, and Latin America. It is spread by direct or indirect contact. The incubation period is long.898 Rhinoscleroma is an opportunistic infection that can occur in patients infected with HIV.

Initially there is a non-specific rhinitis with the development of a purulent nasal discharge and some hypertrophy of the inflamed mucous membrane.898 This is followed by an infiltrative and nodular stage, during which the involved tissues become swollen and eventually deformed.899 Obstruction of the nasal cavity can be caused by the friable inflammatory masses. There is scarring and further deformity in the late stages. That is, there are three stages of development: rhinitic, infiltrative, and cicatricial stages.

It is rare for spontaneous cure to occur, and accordingly, prolonged treatment with antibiotics is required. The tetracyclines, fluoroquinolones, gentamicin, and trimethoprim-sulfamethoxazole have all been used at different times.

Histopathology

In the fully developed lesions of rhinoscleroma the changes are diagnostic, with a variable admixture of plasma cells with conspicuous Russell bodies, and large mononuclear cells with vacuolated cytoplasm (Mikulicz cells). In addition there are some lymphocytes and foci of neutrophils. The Mikulicz cell, which varies from 10 to 100 µm in diameter, is a macrophage. The causative organisms may be seen in the cytoplasm of these cells in PAS and Gram preparations. However, they are best visualized with silver impregnation methods, particularly the Warthin–Starry stain. The organisms can also be seen in smears from the lesions, and they are easily cultured.

The dense inflammatory infiltrate may cause ulceration or atrophy of the overlying mucosa. Sometimes the mucosa is hyperplastic, even to the extent of pseudoepitheliomatous hyperplasia.

Electron microscopy

The vacuolated Mikulicz cells are macrophages with phagosomes containing bacterial mucopolysaccharide as well as some bacteria. There is often fragmentation of the limiting membrane of some of the phagosomes. Plasma cells are sometimes vacuolated to a limited extent. Russell bodies are readily seen in the plasma cells and extracellularly.