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