View source for Rhinosporidium seeberi

* Protozoan head and neck infection previously mistaken for a fungal infection

== Background ==
=== Microbiology ===
* 18S rDNA sequencing has shown that ''Rhinosporidium seeberi'' is a protistan parasite
* Has never been cultured
* Forms round, thick-walled cysts (sporangia) in the submucosa, varying in diameter from 100 to 350 μm, often visible through the mucosa as white dots
* Mature cysts become filled with numerous spores (endospores), which on release become new cysts — kind of like ''Coccidioides''

=== Epidemiology ===
* Occurs worldwide, with most cases in India and Sri Lanka

== Clinical Manifestations ==
* Rhinosporidiosis is a chronic, usually painless localized pedunculated masses of the mucous membranes
* Lesions increase over months to years
* Most commonly affects the nose and nasopharynx, sometimes presenting with nasal obstruction or epistaxis
* Can also affect the eye or orbit, and rarely the skin as verrucous pedunculated lesions
* Rare cases involve the vagina, urethra, or penis
* Dissemination is rare

== Diagnosis ==
* Presumably clinical suspicion with or without PCR or DNA sequencing
* With appropriate history, may be able to determine from biopsy
* Differential for spherules: ''[[Coccidioides]]'', ''[[Rhinosporidium]]'', ''[[Emmonsia]]''

== Management ==
* Surgery with electrocoagulation of the lesion base

== Further Reading ==
* Pfaller MA and Diekema DJ. Unusual Fungal and Pseudofungal Infections of Humans. ''J Clin Microbiol''. 2005;43:1495. doi: [https://doi.org/10.1128/JCM.43.4.1495-1504.2005 JCM.43.4.1495-1504.2005]

{{DISPLAYTITLE:''Rhinosporidium seeberi''}}
[[Category:Protozoa]]