| Mycetoma | |
|---|---|
| Specialty | Infectious diseases |
| Symptoms | Triad: painless firm skin lump, multiple weeping sinuses, grainy discharge [1] |
| Usual onset | Slowly progressive [1] |
| Types |
|
| Diagnostic method | Ultrasound, fine needle aspiration [1] |
Mycetoma is a chronic infection in the skin caused by either bacteria (actinomycetoma) or fungi (eumycetoma), typically resulting in a triad of painless firm skin lumps, the formation of weeping sinuses, and a discharge that contains grains. [1] 80% occur in feet. [1]
Most eumycetoma is caused by M. mycetomatis, whereas most actinomycetoma is caused by N. brasiliensis, S. somaliensis, A. madurae and Actinomadura pelletieri. [1] People who develop mycetoma likely have a weakened immune system. [1] It can take between 3 months to 50 years from time of infection to first seeking healthcare advice. [1]
Diagnosis requires ultrasound and fine needle aspiration. [1]
While most cases of mycetoma occur in Sudan, Venezuela, Mexico, and India, its true prevalence and incidence are not well-known. [2] [3] It appears most frequently in people living in rural areas, particularly in farmers and shepherds, who are often men between 20 and 40 years earning the primary incomes for their families. [1] It has been reported since 1840. [4] Noteworthy, the diagnosis of mycetoma in non-endemic or low endemic areas as Europe and North Africa is challenging. [5] [6] Physicians in these areas are usually unfamiliar with the disease-specific manifestations and need to exercise extra vigilance regarding those patients who are at high risk of contracting mycetoma infections. [7] Recent evidence suggests that Egypt, which borders sub-Saharan Africa, is a low-endemic country. [5] Additionally, recent evidence suggests that Pakistan, which borders India, is a moderate-endemic country. [8] Unlike bacterial acute hematogenous osteomyelitis and septic arthritis, misdiagnosed or delayed diagnosis of mycetoma osteomyelitis can result in amputation or radical resection. [5] The disease is listed by the World Health Organization (WHO) as a neglected tropical disease. [3]
Frequent exposure to penetrating wounds by thorns or splinters is a risk factor. [9] This risk can be reduced by disinfecting wounds and wearing shoes. [10]
Mycetoma is caused by common saprotrophs found in the soil and on thorny shrubs in semi-desert climates. [10] Some common causative agents are: [11]
Infection is caused as a result of localized skin trauma, such as stepping on a needle or wood splinter, or through a pre-existing wound. [10]
The first visible symptom of mycetoma is a typically painless swelling beneath the skin; over several years, this will grow to a nodule (lump). [9] Affected people will experience massive swelling and hardening of the area, in addition to skin rupture and the formation of sinus tracts that discharge pus and grains filled with organisms. [9] In many instances, the underlying bone is affected. [12] [10] Some people with mycetoma will not experience pain or discomfort, while others will report itching and/or pain. [9]
There are currently no rapid diagnostic tools for mycetoma. [3] Mycetoma is diagnosed through microscopic examination of the grains in the nodule and by analysis of cultures. [10] Since the bacterial form and the fungal form of mycetoma infection of the foot share similar clinical and radiological features, diagnosis can be a challenge. [2] Magnetic resonance imaging is a very valuable diagnostic tool. However, its results should be closely correlated with the clinical, laboratory and pathological findings. [12] [13]
Currently, itraconazole is used for the treatment of mycetoma. Recent research found fosravuconazole can also be used to treat the disease. [14]
While treatment will vary depending on the cause of the condition, it may include antibiotics or antifungal medication. [9] Actinomycetoma, the bacterial form, can be cured with antibiotics. [2] Eumycetoma, the fungal form, is treated with antifungals. [13] Surgery in the form of bone resection may be necessary in late presenting cases or to enhance the effects of medical treatment. [12] In the more extensive cases amputation is another surgical treatment option. [15] [10] For both forms, extended treatment is necessary. [2]
Mycetoma is endemic in some regions of the tropics and subtropics. [1] India, sub-Saharan Africa as Sudan, and Mexico are most affected. [1] [16] Pakistan is probably a moderate-endemic country. [8] Sporadic cases have been reported across some North African countries. [17] Egypt is probably a low-endemic country. [5]
In cats, mycetoma can be treated with complete surgical removal. Antifungal drugs are rarely effective. [18]
Melioidosis is an infectious disease caused by a gram-negative bacterium called Burkholderia pseudomallei. Most people exposed to B. pseudomallei experience no symptoms; however, those who do experience symptoms have signs and symptoms that range from mild, such as fever and skin changes, to severe with pneumonia, abscesses, and septic shock that could cause death. Approximately 10% of people with melioidosis develop symptoms that last longer than two months, termed "chronic melioidosis".
Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children e.g. the femur and humerus, while the feet, spine, and hips are most commonly involved in adults.
Fungal infection, also known as mycosis, is a disease caused by fungi. Different types are traditionally divided according to the part of the body affected; superficial, subcutaneous, and systemic. Superficial fungal infections include common tinea of the skin, such as tinea of the body, groin, hands, feet and beard, and yeast infections such as pityriasis versicolor. Subcutaneous types include eumycetoma and chromoblastomycosis, which generally affect tissues in and beneath the skin. Systemic fungal infections are more serious and include cryptococcosis, histoplasmosis, pneumocystis pneumonia, aspergillosis and mucormycosis. Signs and symptoms range widely. There is usually a rash with superficial infection. Fungal infection within the skin or under the skin may present with a lump and skin changes. Pneumonia-like symptoms or meningitis may occur with a deeper or systemic infection.
Eumycetoma, also known as Madura foot, is a persistent fungal infection of the skin and the tissues just under the skin, affecting most commonly the feet, although it can occur in hands and other body parts. It starts as a painless wet nodule, which may be present for years before ulceration, swelling, grainy discharge and weeping from sinuses and fistulae, followed by bone deformity.
Actinomycetoma is a chronic bacterial subcutaneous infection caused by Actinomyces that affect the skin and connective tissue. It is, therefore, a form of actinomycosis. Mycetoma is a broad term which includes actinomycetoma and eumycetoma under it. However, eumycetoma is caused by fungal infection in contrast to actinomycetoma that is caused by mostly anaerobic bacteria. The predominant site of infection is the foot and leg. Both actinomycetoma and eumycetoma show very similar clinical and radiological presentations and are endemic in tropical countries.
Chromoblastomycosis is a long-term fungal infection of the skin and subcutaneous tissue.
Bejel, or endemic syphilis, is a chronic skin and tissue disease caused by infection by the endemicum subspecies of the spirochete Treponema pallidum. Bejel is one of the "endemic treponematoses", a group that also includes yaws and pinta. Typically, endemic trepanematoses begin with localized lesions on the skin or mucous membranes. Pinta is limited to affecting the skin, whereas bejel and yaws are considered to be invasive because they can also cause disease in bone and other internal tissues.
Podoconiosis, also known as nonfilarial elephantiasis, is a disease of the lymphatic vessels of the lower extremities that is caused by chronic exposure to irritant soils. It is the second most common cause of tropical lymphedema after lymphatic filariasis, and it is characterized by prominent swelling of the lower extremities, which leads to disfigurement and disability. Methods of prevention include wearing shoes and using floor coverings. Mainstays of treatment include daily foot hygiene, compression bandaging, and when warranted, surgery of overlying nodules.
Opisthorchiasis is a parasitic disease caused by certain species of genus Opisthorchis. Chronic infection may lead to cholangiocarcinoma, a cancer of the bile ducts.
A rickettsiosis is a disease caused by intracellular bacteria.
Madurella is a fungal genus of Hyphomycetes, of uncertain position in the Sordariales, and sometimes classified as Mitosporic Ascomycota.
Orientia tsutsugamushi is a mite-borne bacterium belonging to the family Rickettsiaceae and is responsible for a disease called scrub typhus in humans. It is a natural and an obligate intracellular parasite of mites belonging to the family Trombiculidae. With a genome of only 2.0–2.7 Mb, it has the most repeated DNA sequences among bacterial genomes sequenced so far. The disease, scrub typhus, occurs when infected mite larvae accidentally bite humans. Primarily indicated by undifferentiated febrile illnesses, the infection can be complicated and often fatal.
Pseudallescheria boydii is a species of fungus classified in the Ascomycota. It is associated with some forms of eumycetoma/maduromycosis and is the causative agent of pseudallescheriasis. Typically found in stagnant and polluted water, it has been implicated in the infection of immunocompromised and near-drowned pneumonia patients. Treatment of infections with P. boydii is complicated by resistance to many of the standard antifungal agents normally used to treat infections by filamentous fungi.
Fenarimol, sold under the tradenames Bloc, Rimidin and Rubigan, is a fungicide which acts against rusts, blackspot and mildew fungi. It is used on ornamental plants, trees, lawns, tomatoes, peppers, eggplants, cucumbers and melons. It is mainly used to control powdery mildew. It works by inhibiting the fungus's biosynthesis of important steroid molecules.
Armillifer grandis is a species of tongue worm in the subclass Pentastomida found in tropical Central and West Africa. Its typical definitive hosts are viperid snakes, while rodents are presumed to act as intermediate hosts. Humans may become accidentally infected by the eggs, particularly if consuming infected snakes. Ingested eggs develop into nymphs that invade different visceral organs, causing a disease that is often called porocephalosis. Most human infections are asymptomatic, although some cases are debilitating and even lethal. Abdominal infections are more widespread, but typically undiagnosed, while ocular manifestations are rare and may cause blindness.
Madurella mycetomatis is a fungus primarily reported in Central Africa as a cause of mycetoma in humans. It has been misclassified for many years, but with improvement of molecular techniques, its phylogenetic classification has been established. Many methods exist to identify M. mycetomatis, both in lesions and in culture. Histological examination is especially useful, as it has many unique morphological features. Strain-level differences in response to antifungal agents is informative for treatment and laboratory isolation of cultures.
Paracoccidioides lutzii is a dimorphic fungus that is one of the causal agents of paracoccidioidomycosis, together with Paracoccidioides brasiliensis. Unlike P. brasiliensis, which is found throughout Central and South America, P. lutzii is found only in Brazil and Ecuador. It is less virulent than P. brasiliensis.
Neglected tropical diseases in India are a group of bacterial, parasitic, viral, and fungal infections that are common in low income countries but receive little funding to address them. Neglected tropical diseases are common in India.
The Global Action For Fungal Infections(GAFFI), is an international foundation focussed on raising awareness of and collecting worldwide data on fungal disease. Its aim is to make reliable and inexpensive diagnostic tests widely available.
Ahmed Hassan Fahal is a Sudanese Professor of Surgery at the University of Khartoum, who specialised in Mycetoma.