| Mycetoma | |
|---|---|
| Classification and external resources | |
Madura Foot |
|
| ICD-10 | B47.0 |
| DiseasesDB | 8472 |
| eMedicine | med/30 derm/280 derm/147 |
| MeSH | D008271 |
Eumycetoma is a chronic, specific, granulomatous,[1] fungal disease.[2] It mainly affects the foot; and Mycetoma pedis is also known as Madura foot. This infection is endemic in Africa, India, and Central and South America.[3]
Contents |
Eumycetoma usually involves the subcutaneous tissue after a traumatic inoculation of the causative organism. Tumefaction and formation of sinus tracts characterize mycetoma. The sinuses usually discharge purulent and seropurulent exudate containing grains. It may spread to involve the skin and the deep structures resulting in destruction, deformity and loss of function; very occasionally it could be fatal.
The true incidence and the geographical distribution of mycetoma throughout the world is not exactly known due to the nature of the disease which is usually painless, slowly progressive which may lead to the late presentation of the majority of patients. Mycetoma has a worldwide distribution but this is extremely uneven. It is endemic in tropical and subtropical regions. The African continent seems to have the highest prevalence. It is found in what is known as the mycetoma belt stretching between the latitudes of 15 south and 30 north. The belt includes Sudan, Somalia, Senegal, India, Yemen, Mexico, Venezuela, Colombia, Argentina and others.
Mycetoma infection, Madura foot or maduromycosis, was originally described in Sanskrit in the Vedic texts from India. The first English language accounts occurred much later in the area of Madras (aka Chennai).
The geographical distribution of the individual mycetoma organism shows considerable variations, which can be convincingly explained on an environmental basis. Areas where mycetoma prevails are relatively arid zones with a short rainy season with a relative humidity.
The organisms are usually present in the soil in the form of grains. The infecting agent is implanted into the host tissue through a breach in the skin produced by trauma caused by sharp objects such as thorn pricks, stone or splinters.
The disease is usually acquired while performing agricultural work, and it generally afflicts men between 20 and 40 years old. The disease is acquired by contacting grains of fungal spores that have been discharged onto the soil. Infection usually involves an open area or break in the skin. Pseudoallescheria boydii is one of many fungi spp. that causes the fungal form of madura foot (see below). The disease is characterized by a yogurt-like discharge upon maturation of the infection. Hematogenous or lymphatic spread is uncommon. Infections normally start in the foot or hand and travel up the leg or arm.
Eumycetoma may be one of several varieties, depending upon color of the granulous discharge:
The bacterial mycetoma species Nocardia (including Nocardia asteroides and Nocardia brasiliensis) produces yellow discharge, and Streptomyces (including Streptomcyes somaliensis) produce yellow or red discharge. These are not causes of Eumycetoma.
The further course of the sinuses differs according to the mycetoma present. In the black variety, the infection spreads mainly subcutaneously. In the red and yellow varieties deep spread occurs early, and muscle and underlying bones become infiltrated, but unexpectedly, nerves and tendons are highly resistant to invasion.[3]
Diagnosis of mycetoma is usually accomplished by radiology, ultrasound or by fine needle aspiration of the fluid within an afflicted area of the body. It depends upon isolating the causative organism along with a knowledge of local endemic infection.
Following is the differential diagnosis:
There are several clinical treatments available for this disease. They include surgery, ketoconazole,[9] voriconazole,[10] itraconazole and amputation. There is no vaccine for mycetoma.
Scientists at such institutions as The Mycetoma Research Center at The University of Khartoum in the Sudan are working on a cure.