Rhinoscleroma

Background

Rhinoscleroma is a rare chronic (slowly progressive) inflammatory condition caused by bacteria called Klebsiella rhinoscleromatis. Rhinoscleroma is characterised by granulomatous swellings (lumpy firm masses composed of immune cells) in the nose and other parts of the respiratory tract, such as the paranasal sinuses, mouth, lips, larynx, trachea, and bronchi. The disease is contracted by inhaling droplets or contaminated material and typically appears in patients aged 10-30 years of age.

Cases of rhinoscleroma generally occur in Central and South America, parts of Africa, the Middle East, India, the Philippines, Central and Eastern Europe, and some areas of the Pacific. Risk factors for the disease include immunodeficiency (particularly HIV infection), poverty, poor hygiene, and prolonged contact with infected patients.

Clinical features of rhinoscleroma

Three clinical stages have been described:

1. Catarrhal stage – patients initially have non-specific symptoms, such as a runny nose or blocked nose. As the disease progresses, the nasal discharge may contain pus and develop a foul odour. Dry crusting of the mucous membranes of the nose can occur. This stage can last for weeks to months.
2. Granulomatous (also called hypertrophic or proliferative) stage – the mucosal tissue inside the nose becomes bluish-red, and rubbery nodules (lumps) form. As these granulomatous swellings grow, they can cause nasal enlargement and deformity. Symptoms include bleeding noses, nasal obstruction (or obstruction elsewhere in the respiratory tract), loss of the sense of smell, a hoarse voice, and thickening or numbing of the soft palate.
3. Sclerotic or fibrotic phase – the granulation tissue is replaced by hardened scars, which can occasionally result in blocked airways.

Diagnosis

1. K rhinoscleromatis can be grown in the laboratory in around 50-60% of cases, using blood agar or MacConkey agar.
2. The organisms may also be seen under the microscope using Gram, Giemsa, and silver staining.
3. Microscopic examination of biopsy samples can reveal characteristic findings, including Mikulicz cells (large immune cells that contain the bacteria).

Treatment

Rhinoscleroma is treated with long-term antibiotics and surgery in patients with symptoms of respiratory tract obstruction.

1. Antibiotics that have been used include streptomycin, tetracycline, rifampicin, trimethoprim-sulfamethoxazole, and ciprofloxacin. Antibiotic treatment alone may be sufficient in early stage disease. Antibiotics are generally required for months to years to prevent recurrent infection.
2. When granulomatous lesions or scarring are present, surgery is often required.