Conidiobolomycosis is a rare long-term fungal infection that is typically found just under the skin of the nose,

sinuses Paranasal sinuses are a group of four paired air-filled spaces that surround the nasal cavity. The maxillary sinuses are located under the eyes; the frontal sinuses are above the eyes; the ethmoidal sinuses are between the eyes and the sphenoid ...

, cheeks and upper lips. It may present with a

nose bleed A nosebleed, also known as epistaxis, is bleeding from the nose. Blood can flow down into the stomach, and cause nausea and vomiting. In more severe cases, blood may come out of both nostrils. Rarely, bleeding may be so significant that low bloo ...

or a blocked or runny nose. Typically there is a firm painless swelling which can slowly extend to the nasal bridge and eyes, sometimes causing facial disfigurement. Most cases are caused by ''

Conidiobolus coronatus ''Conidiobolus coronatus'' is a saprotrophic fungus, first described by Costantin in 1897 as ''Boudierella coronata''. Though this fungus has also been known by the name ''Entomophthora coronata'', the correct name is ''Conidiobolus coronatus''. ...

'', a fungus found in soil and in the environment in general, which can infect healthy people. 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 Insect bites and stings occur when an insect is agitated and seeks to defend itself through its natural defense mechanisms, or when an insect seeks to feed off the bitten person. Some insects inject formic acid, which can cause an immediate skin ...

. The extent of disease may be seen using medical imaging such as CT scanning of the nose and sinus. Diagnosis may be confirmed by

biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a dise ...

, microscopy, culture and histopathology. Treatment is with long courses of antifungals and sometimes cutting out infected tissue. The condition has a good response to antifungal treatment, but can recur. The infection is rarely fatal. The condition occurs more frequently in adults working or living in the tropical forests of South and Central America, West Africa and Southeast Asia. Males are affected more than females. The first case in a human was described in Jamaica in 1965.

Signs and symptoms

The infection presents with firm lumps just under the skin of the nose,

, upper lips, mouth and cheeks. The swelling is painless and may feel "woody". Sinus pain may occur. Infection may extend to involve the nasal bridge, face and eyes, sometimes resulting in facial disfigurement. The nose may feel blocked or have a discharge, and may bleed.

Cause

Conidiobolomycosis is a type of

Entomophthoromycosis Entomophthoramycosis (or Entomophthoromycosis) is a mycosis caused by Entomophthorales. Examples include basidiobolomycosis and conidiobolomycosis. Signs and symptoms Diagnosis A culture of the infected tissue of the individual suspected of havin ...

, the other being

basidiobolomycosis Basidiobolomycosis is a fungal disease caused by '' Basidiobolus ranarum''. It may appear as one or more painless firm nodules in the skin which becomes purplish with an edge that appears to be slowly growing outwards. A serious but less common t ...

, and is caused by mainly ''

'', but also '' Conidiobolus incongruus'' and ''Conidiobolus lamprauges''

Mechanism

Conidiobolomycosis chiefly affects the central face, usually beginning in the nose before extending onto paranasal sinuses, cheeks, upper lip and pharynx. 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. It can attach to underlying tissues, but not bone. It can be acquired by direct infection through a small cut in the skin such as an

. Thrombosis, infarction of tissue and spread into blood vessels does not occur. Deep and systemic infection is possible in people with a

weakened immune system Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that a ...

. Infection causes a local chronic granulomatous reaction.

Diagnosis

The condition is typically diagnosed after noticing facial changes. The extent of disease may be seen using medical imaging such as CT scanning of the nose and sinus. Diagnosis can be confirmed by

, microscopy, and culture. Histology reveals wide but thin-walled fungal filaments with branching at right-angles. There are only a few septae. The fungus is fragile and hence rarely isolated. An immunoallergic reaction might be observed, where a local antigen–antibody reaction causes

eosinophil Eosinophils, sometimes called eosinophiles or, less commonly, acidophils, are a variety of white blood cells (WBCs) and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates. A ...

s and hyaline material to surround the organism. Molecular methods may also be used to identify the fungus.

Differential diagnosis

Differential diagnosis includes soft tissue tumors. Other conditions that may appear similar include

mucormycosis Mucormycosis, also known as black fungus, is a serious fungal infection that comes under fulminant fungal sinusitis, usually in people who are immunocompromised. It is curable only when diagnosed early. Symptoms depend on where in the body the ...

cellulitis Cellulitis is usually a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of ...

rhinoscleroma Rhinoscleroma, is a chronic granulomatous bacterial disease of the nose that can sometimes infect the upper respiratory tract.Palmer & Reeder. It most commonly affects the nasal cavity—the nose is involved in 95–100 per cent of cases—however, ...

and

lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enla ...

Treatment

Treatment is with long courses of antifungals and sometimes cutting out infected tissue. Generally, treatment is with

triazoles A triazole is a heterocyclic compound featuring a five-membered ring of two carbon atoms and three nitrogen atoms with molecular formula C2H3N3. Triazoles exhibit substantial isomerism, depending on the positioning of the nitrogen atoms within the ...

, preferably

itraconazole Itraconazole, sometimes abbreviated ITZ, is an antifungal medication used to treat a number of fungal infections. This includes aspergillosis, blastomycosis, coccidioidomycosis, histoplasmosis, and paracoccidioidomycosis. It may be given by mo ...

. A second choice is

potassium iodide Potassium iodide is a chemical compound, medication, and dietary supplement. It is a medication used for treating hyperthyroidism, in radiation emergencies, and for protecting the thyroid gland when certain types of radiopharmaceuticals are u ...

, either alone or combined with itraconazole. In severe widespread disease,

amphotericin B Amphotericin B is an antifungal medication used for serious mycosis, fungal infections and leishmaniasis. The fungal infections it is used to treat include mucormycosis, aspergillosis, blastomycosis, candida infections, candidiasis, coccidioidomy ...

may be an option. The condition has a good response to antifungal treatment, but can recur. The infection is rarely fatal but often disfiguring.

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, as well India, Saudi Arabia and Oman. ''Conidiobolus'' species have been found in areas of high humidity such as the coasts of the United Kingdom, eastern United States and West Africa. Adults are affected more than children. Males are affected more than females.

History

The condition was first reported in 1961 in horses in Texas. The first case in a human was described in 1965 in Jamaica. Previously this genus was thought to only infect insects.

Other animals

Conidiobolomycosis affects spiders, termites and other arthropods. The condition has been described in dogs, horses, sheep and other mammals. Affected mammals typically present with irregular lumps in one or both nostrils that cause obstruction, bloody nasal discharge and noisy abnormal breathing.

References

External links

{{Mycoses Animal fungal diseases Fungal diseases