| Conidiobolomycosis | |
|---|---|
| Other names | Rhinoentomophthoromycosis[1] |
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| Conidiobolus coronatus[2] | |
| Specialty | Infectious disease[3] |
| Symptoms | Firm painless swelling in nose, sinuses, cheeks and upper lips, blocked nose, runny nose, nose bleed[4] |
| Complications |
|
| Usual onset | Slowly progressive[6] |
| Duration | Long term[4] |
| Causes | fungi of the genus Conidiobolus[4] |
| Diagnostic method | Medical imaging, biopsy, microscopy, culture[5] |
| Differential diagnosis | Soft tissue tumors,[4] Mucormycosis |
| Treatment | Antifungals, surgical debridement[6] |
| Medication | oral Itraconazole, topical Potassium iodide[6] Severe disease: intravenous Amphotericin B[5] |
| Prognosis | Longterm morbidity: facial disfigurement,[4] good response to treatment[7] |
| Frequency | Rare, M>F[4] adults>children[5] |
| Deaths | Rare[6] |
Conidiobolomycosis is a rare long-term fungal infection that is typically found just under the skin of the nose, sinuses, cheeks and upper lips.[3][4] It may present with a nose bleed or a blocked or runny nose.[4] Typically there is a firm painless swelling which can slowly extend to the nasal bridge and eyes, sometimes causing facial disfigurement.[6]
Most cases are caused by Conidiobolus coronatus, a fungus found in soil and in the environment in general, which can infect healthy people.[4] It is usually acquired by inhaling the spores of the fungus, but can be by direct infection through a cut in the skin such as an insect bite.[3][4]
The extent of disease may be seen using medical imaging such as CT scanning of the nose and sinus.[4] Diagnosis may be confirmed by biopsy, microscopy, culture and histopathology.[4][5] Treatment is with long courses of antifungals and sometimes cutting out infected tissue.[6] The condition has a good response to antifungal treatment,[7] but can recur.[8] The infection is rarely fatal.[6]
The condition occurs more frequently in adults working or living in the tropical forests of South and Central America, West Africa and Southeast Asia.[4][5] Males are affected more than females.[4] The first case in a human was described in Jamaica in 1965.[4]
The infection presents with firm lumps just under the skin of the nose, sinuses, upper lips, mouth and cheeks.[4] The swelling is painless and may feel "woody".[8] Sinus pain may occur.[6] Infection may extend to involve the nasal bridge, face and eyes, sometimes resulting in facial disfigurement.[4] The nose may feel blocked or have a discharge, and may bleed.[4]
Conidiobolomycosis is a type of Entomophthoromycosis, the other being basidiobolomycosis, and is caused by mainly Conidiobolus coronatus, but also Conidiobolus incongruus and Conidiobolus lamprauges[4]
Conidiobolomycosis chiefly affects the central face, usually beginning in the nose before extending onto paranasal sinuses, cheeks, upper lip and pharynx.[5] The disease is acquired usually by breathing in the spores of the fungus, which then infect the tissue of the nose and paranasal sinuses, from where it slowly spreads.[4] It can attach to underlying tissues, but not bone.[4][5] It can be acquired by direct infection through a small cut in the skin such as an insect bite.[3] Thrombosis, infarction of tissue and spread into blood vessels does not occur.[4] Deep and systemic infection is possible in people with a weakened immune system.[4] Infection causes a local chronic granulomatous reaction.[6]
The condition is typically diagnosed after noticing facial changes.[6] The extent of disease may be seen using medical imaging such as CT scanning of the nose and sinus.[4] Diagnosis can be confirmed by biopsy, microscopy, and culture.[4] Histology reveals wide but thin-walled fungal filaments with branching at right-angles.[5] There are only a few septae.[5] The fungus is fragile and hence rarely isolated.[1] An immunoallergic reaction might be observed, where a local antigen–antibody reaction causes eosinophils and hyaline material to surround the organism.[5] Molecular methods may also be used to identify the fungus.[5]
Differential diagnosis includes soft tissue tumors.[4] Other conditions that may appear similar include mucormycosis, cellulitis, rhinoscleroma and lymphoma.[6]
Treatment is with long courses of antifungals and sometimes cutting out infected tissue.[6] Generally, treatment is with triazoles, preferably itraconazole.[5] A second choice is potassium iodide, either alone or combined with itraconazole.[5] In severe widespread disease, amphotericin B may be an option.[5] The condition has a good response to antifungal treatment,[7] but can recur.[8] The infection is rarely fatal but often disfiguring.[6]
The disease is rare, occurring mainly in those working or living in the tropical forests of West Africa, Southeast Asia, South and Central America,[4] as well India, Saudi Arabia and Oman.[5] Conidiobolus species have been found in areas of high humidity such as the coasts of the United Kingdom, eastern United States and West Africa.[6]
Adults are affected more than children.[5] Males are affected more than females.[4]
The condition was first reported in 1961 in horses in Texas.[4] The first case in a human was described in 1965 in Jamaica.[4] Previously this genus was thought to only infect insects.[4]
Conidiobolomycosis affects spiders, termites and other arthropods.[4] The condition has been described in dogs, horses, sheep and other mammals.[9] Affected mammals typically present with irregular lumps in one or both nostrils that cause obstruction, bloody nasal discharge and noisy abnormal breathing.[9]