Conidiobolomycosis
Other names	Rhinoentomophthoromycosis [1]
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	Facial disfigurement, partial or full blindness. [4] Severe disseminated disease if weak immune system [5]
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]

Signs and symptoms

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]

Cause

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]

Mechanism

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]

Diagnosis

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

Differential diagnosis includes soft tissue tumors. ^[4] Other conditions that may appear similar include mucormycosis, cellulitis, rhinoscleroma and lymphoma. ^[6]

Treatment

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]

Epidemiology

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]

History

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]

Other animals

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]

References

External links