Rhinoscleroma is a chronic, progressive, and infectious granulomatous disease. It primarily originates in the nasal area and can spread to the paranasal sinuses, soft palate, hard palate, pharynx, larynx, trachea, bronchi, nasolacrimal ducts, and middle ear. It also has the potential to manifest or develop secondarily at various points along the respiratory tract, leading it to be referred to as respiratory tract scleroma. Rhinoscleroma is considered a sporadic disease and has been reported globally.
Etiology
In 1882, Frisch was the first to isolate Klebsiella rhinoscleromatis (also known as Frisch's bacillus) from affected tissues, identifying it as the causative organism of rhinoscleroma. However, it has also been proposed that this disease results from a combined effect of both viruses and Klebsiella rhinoscleromatis. The disease has mild infectivity, but the exact mode of transmission remains uncertain.
Pathology
The disease typically has a prolonged course and progresses through three stages: the catarrhal stage, the sclerotic stage, and the cicatricial stage. Distinct pathological features characterize each stage, though overlap of stages may occur.
Catarrhal Stage
This stage involves lymphocytic and plasma cell infiltration in the mucosal and submucosal layers. Klebsiella rhinoscleromatis can be observed in the interstitial spaces.
Sclerotic Stage
This stage is also referred to as the granulomatous stage. Histological examination reveals the presence of large foamy cells (Mikulicz cells) along with eosinophilic inclusions (Unna or Russell bodies). The appearance of Mikulicz cells, Russell bodies, and Klebsiella rhinoscleromatis constitutes the main pathological hallmarks of rhinoscleroma, serving as critical criteria for pathological diagnosis.
Cicatricial Stage
This stage is characterized by a marked proliferation of fibrous tissue within the affected areas. Mikulicz cells and Russell bodies decrease or disappear completely.
Clinical Manifestations
Catarrhal Stage
Early symptoms include nasal mucosal dryness, nasal obstruction, and mucopurulent nasal discharge. As the disease progresses, symptoms such as mucosal atrophy, crusting, and bleeding may develop. The condition may clinically resemble atrophic rhinitis but lacks the characteristic foul odor and primarily affects the anterior part of the nasal cavity with crusts that are difficult to remove. This stage may persist for months or even years.
Sclerotic Stage
This stage primarily presents with nasal obstruction and deformity of the external nose. Nodular masses form within the nasal cavity, with a firm, cartilage-like texture. These masses are commonly located in the nasal vestibule, anterior nares, nasal alae, anterior nasal septum, and upper lip. The nodules have a shiny surface and appear purplish-red. Secondary infection may lead to ulceration, purulent crusting, and a foul smell over the nodular surface. This stage may last for several years or even longer.
Cicatricial Stage
Symptoms such as nasal obstruction, hypernasal speech, hoarseness, or respiratory difficulty may arise as a result of cicatricial contraction. Signs include narrowing or occlusion of the anterior nares, inward migration of the nasal alae, disappearance of the uvula, and pharyngeal-laryngeal stenosis.
Diagnosis and Differential Diagnosis
Clinical Presentation
Early manifestations are often nonspecific and may lead to misdiagnosis. Biopsy, bacterial culture, and serological detection of specific antibodies are necessary in suspected cases.
Pathological Diagnosis
This is the primary diagnostic method. The presence of Mikulicz cells and Russell bodies is characteristic of rhinoscleroma. Repeat sampling may be required to avoid misdiagnosis or missed diagnosis.
Laboratory Testing
Serological testing for antibodies against Klebsiella rhinoscleromatis can assist in the diagnosis. Bacterial cultures from affected tissues or nasal secretions may identify Klebsiella rhinoscleromatis.
Endoscopy and CT Imaging
These modalities help determine the location and extent of the lesions.
The disease should be differentiated from atrophic rhinitis, syphilis, tuberculosis, leprosy, malignant granulomas, and tumors.
Treatment
Pharmacological Therapy
The primary focus of treatment is the eradication of Klebsiella rhinoscleromatis. Medications include streptomycin, kanamycin, tetracycline, rifampin, and clofazimine.
Radiation Therapy
Radiotherapy promotes lesion fibrosis and halts disease progression. Combination therapy with medications produces more favorable outcomes.
Surgical Treatment
Surgical excision or reconstruction is an option for correcting cicatricial deformities. Tracheostomy may be performed in cases where involvement of the larynx or trachea leads to breathing difficulties.
Criteria for Cure
Successful treatment is indicated by negative bacterial cultures and the absence of the characteristic pathological changes of rhinoscleroma confirmed by biopsy.