Rhinosporidiosis
Rhinosporidiosis is a rare fungal infection characterized by the development of reddish-purple, tumor-like masses on mucous membranes, particularly affecting the nasal cavity, eyes, and occasionally other body parts such as the skin and genitals. The causative agent, Rhinosporidium seeberi, is an aquatic organism with both fungal and protozoal characteristics, believed to be a parasite of fish. This infection is most prevalent in tropical regions, particularly in countries like India and Sri Lanka, and is associated with exposure to contaminated water, such as during swimming or drinking.
Individuals at higher risk include children, particularly boys and men, as well as those living in rural areas with limited access to sanitation and healthcare. Symptoms can range from nasal obstruction and drainage to issues with vision when tumors form in the eye. Although rhinosporidiosis can be chronic, it is rarely life-threatening. Diagnosis typically involves a microscopic examination of tissue samples, while treatment often requires surgical removal of the growths, as antifungal medications have limited effectiveness. Preventive measures include avoiding potentially contaminated water sources and being cautious when in endemic areas.
Rhinosporidiosis
- ANATOMY OR SYSTEM AFFECTED: Eyes, nose, skin
Definition
Rhinosporidiosis is a fungal infection that causes reddish-purple, tumorlike masses on the nasal mucous membrane, the conjunctiva of the eye, or the urethra. Such masses can extend to the lips, palate, uvula, epiglottis, larynx (voice box), trachea (windpipe), bronchi, ears, scalp, genitals, rectum, and skin.
Causes
Rhinosporidiosis is caused by the organism Rhinosporidium seeberi, which has features of both fungi and protozoa. Genetic analysis has determined that R. seeberi is a member of a group of aquatic parasites of the class Mesomycetozoea. It is theorized that R. seeberi is a parasite of fish.
Risk Factors
The greatest number of rhinosporidiosis cases has been reported in India and Sri Lanka, but the infection has been diagnosed in persons from the Americas, Europe, Africa, and Asia. It is most common in tropical areas. The reservoir of this microorganism and the mode of transmission are unknown, although R. seeberi appears to be associated with drinking contaminated water or with bathing or swimming in contaminated water. Rhinosporidiosis is more common in children and in boys and men. Other risk factors for rhinosporidiosis include living in rural locations in endemic areas where there is greater risk of coming into contact with contaminated water and soil; working in occupations, such as farming and fishing, where there is also a risk of coming into contact with contaminated water and soil; being of low socioeconomic status; which impedes access to proper sanitation and healthcare; and having a compromised immune system.
Symptoms
The tumors of rhinosporidiosis grow from a stem and bleed easily. They have whitish spots, which are the spores. These tumors can obstruct the nose and cause increased nasal drainage, nosebleeds, headaches, cough, sneezing, and postnasal discharge. The tumors in the eye can cause excessive tearing, itching, blurred vision, drooping eyelids, redness, photophobia, and infection. The tumors are not painful, but their presence is felt as pressure. The condition can be chronic, but it is rarely fatal.
Screening and Diagnosis
There is no routine screening for rhinosporidiosis, but because of the external location of the growths, they are easy to see. Diagnosis is based on viewing tissue smears of the growths under a microscope. R. seeberi resembles Coccidioides immitis, so infection with C. immitis must be ruled out. C. immitis has smaller endospores and cannot be stained with the same fungal stains as R. seeberi. Cytology may be used to directly examine the spores, and histopathology of biopsied specimens can also provide a closer examination.
Treatment and Therapy
The treatments for infection with R. seeberi are intravenous antifungal medications, such as amphotericin B and dapsone, and surgical removal of the growth using cauterization. Antifungal drugs have not been particularly effective, and they must be administered for a minimum of one year. Surgery is the treatment of choice. The growth must be removed at its base with a wide excision to prevent tumor recurrence.
Prevention and Outcomes
Because there appears to be a correlation with swimming and bathing in contaminated fresh water, one should avoid swimming or bathing in waters in tropical countries where R. seeberi is endemic. Also, one should avoid drinking from contaminated water sources in these countries. Any freshwater body that is associated with rhinosporidiosis should be avoided. Care should also be taken in rural areas and when interacting with soil in areas with the infection is endemic.
Bibliography
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Fredricks, D. N., et al. "Rhinosporidium seeberi: A Human Pathogen from a Novel Group of Aquatic Protistan Parasites." Emerging Infectious Diseases, vol. 6, no. 3, 2000, pp. 273-282, doi.org/10.3201/eid0603.000307. Accessed 13 Oct. 2024.
Kumari, Rashmi, et al. "Disseminated Cutaneous Rhinosporidiosis." Dermatology Online Journal, vol. 11, no. 1, 1 Mar. 2005, p. 19.
Mayet, H., et al. "Case Report of Nasal Rhinosporidiosis in South Africa." Emerging Infectious Diseases, vol. 30, no. 4, 2024, pp. 766-769, doi.org/10.3201/eid3004.240018.
Penagos, Sara, et al. "Rhinosporidiosis in the Americas: A Systematic Review of Native Cases." The American Journal of Tropical Medicine and Hygiene, vol. 105, no. 1, 2021, pp. 171-175, doi.org/10.4269/ajtmh.20-1411. Accessed 13 Oct. 2024.
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