Introduction
Background
Rhinosporidiosis is a chronic granulomatous infection of the mucous membranes that usually manifests as vascular friable polyps that arise from the nasal mucosa or external structures of the eye. Initially described by Seeber in 1900 in an individual from Argentina, rhinosporidiosis is endemic in India, Sri Lanka, South America, and Africa. Many cases from the United States and Southeast Asia, as well as scattered occurrences throughout the world, have been reported. Most cases of rhinosporidiosis occur in persons from or residing in the Indian subcontinent or Sri Lanka.
The etiologic agent, Rhinosporidium seeberi, has never been successfully propagated in vitro. Initially thought to be a parasite for more than 50 years, R seeberi had been considered a water mold. Molecular biological techniques have recently demonstrated that this organism is an aquatic protistan parasite. It is currently included in a new class, the Mesomycetozoea, along with organisms that cause similar infections in amphibians and fish.
Pathophysiology
Rhinosporidiosis is an infection that is typically limited to the mucosal epithelium. Infection usually results from a local traumatic inoculation with the organism. The disease progresses with the local replication of R seeberi and associated hyperplastic growth of host tissue and a localized immune response.
Infection of the nose and nasopharynx is observed in 70% of persons with rhinosporidiosis; infection of the palpebral conjunctivae or associated structures (including the lacrimal apparatus) is observed in 15%.
Other structures of the mouth and upper airway may be sites of disease. Disease of the skin, ear, genitals, and rectum has also been described. Genital disease has been described in the vagina, penile urethra or meatus, and scrotum. Dissemination of infection has been described in only 3 individuals.
Frequency
United States
Cases in the United States are rare but are more common in Texas and the Southeast.
International
Rhinosporidiosis usually affects persons in or from southern India and Sri Lanka. Cases have been reported worldwide, with an increased incidence in South America and Africa.
Mortality/Morbidity
Rhinosporidiosis can cause prolonged painless disease with limited morbidity. Disease of up to 30 years' duration has been reported. Secondary bacterial infection can cause morbidity. Death has been reported in only the few rare reports of disseminated disease.Race
Rhinosporidiosis has no known racial predilection.
Sex
Men are affected more commonly than women, with a male-to-female ratio of 4:1.
Age
The disease most commonly occurs in children and in individuals aged 15-40 years.
Clinical
History
- Nasal disease may present with unilateral nasal obstruction or epistaxis. Other symptoms may include local pruritus, coryza with sneezing, rhinorrhea, and postnasal discharge with cough. Patients often report a sensation that a foreign body is present in their nasal canal.
- Eye involvement is initially asymptomatic. Increased tearing may be reported as the disease progresses. Photophobia, redness, and secondary infection may occur.
- Skin lesions begin as papillomas that gradually become verrucous.
Physical
- Soft polyps may develop on the nose or eye. These polyps are pink to deep red, are sessile or pedunculated, and are often described as strawberrylike in appearance. Because the polyps of rhinosporidiosis are vascular and friable, they bleed easily upon manipulation.
- This appearance results from sporangia, which is visible as gray or yellow spots in the vascular polypoid masses.
Causes
- The etiologic agent of rhinosporidiosis, R seeberi, has traditionally been considered a fungus. Recent 18S ribosomal ribonucleic acid (rRNA) gene analysis has placed R seeberi into a novel group of aquatic parasites of the class Mesomycetozoea, some of which cause similar diseases in amphibians and fish.
- Most persons with rhinosporidiosis have had bathing or working exposure to stagnant water.
- No immune deficiency has been associated with infection.
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References
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Further Reading
Keywords
rhinosporidiosis, chronic granulomatous infection, Rhinosporidium seeberi, R seeberi, vascular friable polyps, mucosal epithelium infection
