A mycetoma is a potentially serious condition that causes swelling under the foot. Abscesses also develop and discharge comes from all kinds of skin lesions. This tropical disease appears due to repeated and prolonged damage to the skin that allows bacteria or fungi to enter the body. The skin infection that then occurs penetrates to the deeper tissues. Early detection and treatment is necessary because the symptoms worsen and lead to serious complications, such as a deformed or no longer functional foot. Antibiotics or antifungals cure the tropical disease; although treating the infection often takes a lot of time.

• Synonyms of mycetoma
• Epidemiology of infection
• Causes

• Bacteria and fungi
• Handover

• Risk factors of tropical disease
• Symptoms: Swelling of foot with abscesses and discharge
• Diagnosis and examinations
• Therapy
• Prognosis
• Complications of disease due to fungi and bacteria
• Prevention

Synonyms of mycetoma

Synonyms for a mycetoma are:

• eumycetoma
• eumycetoma
• Maduramycosis
• Madurafoot
• Madura foot
• Maduromycosis
• Maduromycosis
• mycetoma

Epidemiology of infection

The number of patients with a mycetoma worldwide is unknown as of October 2020, but between 1950 and 2013 the medical literature reports almost ten thousand patients with the disease. However, the actual number of patients is probably much higher. A mycetoma occurs in people of all ages. Men are affected more often than women due to environmental and probably also hormonal factors. This disease mainly affects poor people living in rural areas of Africa, Latin America and Asia that are near the Earth’s equator and have a dry climate.

Causes

Bacteria and fungi

A mycetoma is a so-called tropical condition that results from certain types of bacteria ( actinomycetoma ) or fungi ( eumycetoma ) present on the soil and in the water. An actinomycotic mycetoma results from aerobic species of actinomycetes belonging to the genera Nocardia, Streptomyces and Actinomadura with Nocardia brasiliensis, Actinomadura madurae, Actinomadura pelletieri and Streptomyces somaliensis being the most common. A eumycotic mycetoma is associated with various fungi, of which Madurella mycetomatis is the most common.

Handover

The spread of the infection occurs through repeated and prolonged damage to the skin (wounds or skin lesions), usually on the patient’s foot, allowing the bacteria or fungi to enter the body. The resulting infection causes firm, usually painless but debilitating growths under the skin that eventually affect the underlying bone. The infection is not transmissible from person to person.

Risk factors of tropical disease

Farmers and livestock farmers are affected more often. Travelers rarely contract the infection, because a mycetoma only develops after prolonged and repeated exposure of the pathogen to the damaged skin.

Symptoms: Swelling of foot with abscesses and discharge

The symptoms of a mycetoma caused by bacteria or fungi are similar. Symptoms usually occur in the foot, but a hand, head, neck, chest, shoulder and arm may also be affected.The infected foot is swollen (swollen foot). Painless small abscesses appear under the skin of the affected foot. Over time, these growths enlarge, and purulent skin ulcers develop. In addition, various openings are created in the foot. These openings often produce a discharge with red, white, yellow or black grains. Furthermore, papules, pustules and nodules appear later under the foot from which a discharge also appears. This infection eventually leads to severe deformity of the foot, or else the patient is unable to use his foot. The skin on the top of the foot shows hypopigmentation (lighter in skin color) or hyperpigmentation (darker in skin color). The overlying skin sometimes sweats excessively (hyperhidrosis) due to an enlargement of a sweat gland and an increased local temperature due to increased blood flow secondary to the inflammatory process.

Diagnosis and examinations

Diagnostic examination The diagnosis of a mycetoma is often made at an advanced stage in which permanent disfigurement of the affected part has already occurred. Diagnosis of a mycetoma requires a deep surgical biopsy (small tissue sample) of the infected area. A laboratory culture determines the specific pathogen. This is necessary to be able to apply the correct treatment. Imaging studies are also useful in diagnosing a mycetoma and visualizing damage to the muscles and bones. The doctor usually uses an X-ray or ultrasound for this.Differential diagnosis The doctor must distinguish a mycetoma from various infectious and non-infectious conditions such as:

• actinomycosis (bacterial infection with swelling and suppuration)
• blastomycosis of the skin (fungal infection)
• botryomycosis
• chromoblastomycosis (fungal infection)
• chromomycosis
• cutaneous tuberculosis (bacterial infection)
• dermatophyte pseudomycetomas
• a mossy foot
• a sarcoma (cancer in connective tissue) of the skin and soft tissue or bones
• Kaposi’s sarcoma (tumor on the skin)
• leprosy (infection with nerve damage and symptoms of the eyes and skin)
• non-tuberculous mycobacterial infections of the skin
• osteomyelitis (inflammation of the bone marrow, bacterial or tubercular)
• podoconiosis (disease with pain, swelling and itching of the foot)
• sporotrichosis (fungal skin infection)
• syphilis (bacterial infection through sexual contact)

Therapy

Treatment for a mycetoma consists of antibiotics when an actinomycetoma is present, or antifungal medications when a eumycetoma is present. Usually the patient has to take these medications for many months. Sometimes surgery is necessary to cut away the infected tissue (surgical debridement). In severe cases, amputation of the foot is necessary. Especially when a mycetoma is the result of fungi, the medications are not always effective and surgical intervention is often required.

Prognosis

A mycetoma is a devastating chronic subcutaneous (under the skin) granulomatous inflammatory disease caused by various true fungi and bacteria. The disease is characterized by numerous deformities and limitations, high morbidity and in the late phase the disease is possibly fatal. Prompt diagnosis and treatment prevents these complications, although treatment is often difficult and lengthy.

Complications of disease due to fungi and bacteria

Left untreated or when treatment fails, various complications arise, such as:The spread of the infection to other parts of the body, such as the lungs

• ankylosis (joint stiffness)
• atrophy of the disused limbs (decrease in size and strength)
• chronic edema
• a secondary bacterial infection
• a destruction of the underlying muscles and bones resulting in osteomeylitis (bone infection).
• loss of function
• deformities
• pain

Prevention

Wearing well-fitting shoes prevents a mycetoma.

read more

• Abscess in skin or body: Pus due to infection with bacteria
• Foot pain: Causes of sore foot or foot pain