Basidiobolomycosis is a fungal disease caused by ''

Basidiobolus ranarum ''Basidiobolus'' is a fungus genus. It was circumscribed by the mycologist in 1886, with '' Basidiobolus ranarum'' assigned as the type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''spe ...

''. 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 type affects the stomach and intestine, which usually presents with

abdominal pain Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues. Since the abdomen contains most of the body's vital organs, it can be an indicator of a wide variety of diseases. Given th ...

, fever and a

mass Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physi ...

. ''B. ranarum'', can be found in soil, decaying vegetables and has been isolated from insects, some reptiles, amphibians, and mammals. The disease results from direct entry of the fungus through broken skin such as an insect bite or trauma, or eating contaminated food. It generally affects people who are well. Diagnosis is by

medical imaging Medical imaging is the technique and process of imaging the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues (physiology). Medical imaging seeks to revea ...

biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, an interventional radiologist, or an interventional cardiology, interventional cardiologist. The process involves the extraction of sampling (medicine), sample ...

microscopy Microscopy is the technical field of using microscopes to view subjects too small to be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of microscopy: optical mic ...

, culture and histopathology. Treatment usually involves

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

and surgery. Although ''B. ranarum'' is found around the world, the disease Basidiobolomycosis is generally reported in

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

and

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

areas of Africa, South America, Asia and

Southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural list of regions of the United States, region of the United States that includes Arizona and New Mexico, along with adjacen ...

. It is rare. The first case in a human was reported from Indonesia in 1956 as a skin infection.

Signs and symptoms

Basidiobolomycosis may appear as a firm

nodule Nodule may refer to: * Nodule (geology), a small rock or mineral cluster * Manganese nodule, a metallic concretion found on the seafloor *Nodule (medicine), a small aggregation of cells *Root nodule Root nodules are found on the roots of plants, ...

in the skin which becomes purplish with an edge that appears to be slowly growing outwards. It is generally painless but may feel itchy or burning. There can be one lesion or several, and usually on the arms or legs of children. Pus may be present if a bacterial infection also occurs. The infection can spread to nearby structures such as muscles, bones and lymph nodes. A serious but less common type affects the stomach and intestine, which usually presents with tummy ache, fever and a lump. Lymphoedema may occur.

Mechanism

Basidiobolomycosis is a type of Entomophthoromycosis, the other being conidiobolomycosis, and is caused by ''

'', a fungus belonging to the order

Entomophthorales The Entomophthorales are an order of fungi that were previously classified in the class Zygomycetes. A new subdivision, Entomophthoromycotina, in 2007, was circumscribed for them. Most species of the entomophthorales are pathogens of insects ...

. ''B. ranarum'' has been found in soil, decaying vegetables and has been isolated from insects some reptiles, amphibians, and mammals. The disease results from direct entry of the fungus through broken skin such as an insect bite or trauma, or eating contaminated food. Diabetes may be a risk factor. The exact way in which infection results is not completely understood.

Diagnosis

Diagnosis is by

culture Culture ( ) is a concept that encompasses the social behavior, institutions, and Social norm, norms found in human societies, as well as the knowledge, beliefs, arts, laws, Social norm, customs, capabilities, Attitude (psychology), attitudes ...

and

. A review in 2015 showed that the most common finding on

imaging Imaging is the representation or reproduction of an object's form; especially a visual representation (i.e., the formation of an image). Imaging technology is the application of materials and methods to create, preserve, or duplicate images. ...

of the abdomen was a mass in the bowel, the liver, or multiple sites and bowel wall thickening. Initially, many were considered to have either a cancer of the bowel or Crohns disease.

Treatment

Treatment usually involves

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 ...

, combined with surgical debridement. Bowel involvement may be better treated with voriconazole.

Epidemiology

The condition is rare but emerging. Men and children are affected more than females. The disease is generally reported in

and

areas of Africa, South America, Asia and several cases in

History

The first case in a human was reported from Indonesia as a skin infection in 1956. In 1964, the first case involving stomach and intestine was reported.

Society and culture

Cases among gardeners in Arizona, US, may indicate an occupational hazard, but is unproven.