Mycetoma is a localized chronic, suppurative and deforming granulomatous infectious disease of subcutaneous tissue, skin and bones, which is present worldwide and is endemic in tropical and subtropical regions. Mycetoma is a pathological process in which the causative agents – a fungus (eumycetoma) or a bacterium (actinomycetoma) from an exogenous source produce grains.
Since the treatment of these two etiologies is entirely different, a definite diagnosis after histopathological and microbiolological examination is mandatory. The disease is notoriously difficult to treat. Treatment consists of long courses of antifungals and antibacterials often combined with surgery. The disease was first described in the Madura district of India in 1842, (Madura foot).
Infection probably comes from the soil or animal dung, and it is suspected that most patients are infected by walking barefoot and sustaining minor cuts from thorns, which allows the pathogen to enter the body.
Eumycetoma Caused by a several mould fungi. The most common are Madurella mycetomatis, Madurella grisea, and Pseudallescheria boydii. The color of grains is black or white Actinomycetoma Caused by aerobic filamentous bacteria, gram positive Actinomadura madurae, Streptomyces somaliensis, Nocardia brasiliensis. Color of grains yellow, white, yellowish-brown, pinkish – red.
The most common symptoms are painless masses under the skin that slowly grow to become large, badly oozing sores that expel “grains” and ultimately cause the affected limb to become deformed or unusable. These masses usually appear on a person’s foot but can form anywhere on the body.
Mycetoma commonly affects young adults, mostly males aged between 15 and 30 years. People of low socioeconomic status and manual workers such as farmers, labourers, and herdsmen are the worst affected. The psychological impact of mycetoma is severe: many patients become depressed and need psychological support.
There are no point-of-care diagnostic tests for use in mycetoma-endemic villages. Most available mycetoma diagnostic tests and techniques are invasive, expensive, lengthy, of low specificity and sensitivity, and not available in endemic regions. People must travel long distances to provincial hospitals to access them.
The treatment depends on the cause. For the bacterial type (actinomycetoma), combination antibiotics are used, with up to 90% cure rates. For the fungal type (eumycetoma), a combination of antifungal drugs and surgery is used. Available eumycetoma treatment is frustratingly ineffective, even after 12 months of treatment, and very expensive, with many side effects.
The fungal form of mycetoma requires prolonged use of limited antifungal drugs with low cure rates (around 25–35%) and a high chance of disease recurrence. Ketoconazole and itraconazole are the main antifungal drugs currently used for treating eumycetoma.
Treatment courses last for a minimum of one year, and repeated courses may be necessary – often to no avail. Ketoconazole has side effects, and concern over its liver toxicity has caused the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) to restrict its use.
Actinomycetoma: Trimethoprim-sulfamethoxazole, Dapsone, Streptomycin. Combination of 2 drugs is used