MADURA FOOT- MYCETOMA

Mycetoma is a chronic subcutaneous infection caused by actinomycetes or fungi. This infection results in a granulomatous inflammatory response in the deep dermis and subcutaneous tissue, which can extend to the underlying bone.
Mycetoma is characterized by the formation of grains containing aggregates of the causative organisms that may be discharged onto the skin surface through multiple sinuses. Mycetoma was first described in the mid 1800s and initially named Madura foot, after the region of Madura in India where the disease was first identified.

The body parts affected most commonly in persons with mycetoma include the foot or lower leg, with infection of the dorsal aspect of the forefoot being typical. The hand is the next most common location; however, mycetoma lesions can occur anywhere on the body. Lesions on the chest and back are frequently caused by Nocardia species, whereas lesions on the head and neck are usually caused by Streptomyces somaliensis.

The causative organism enters through sites of local trauma (eg, cut on the hand, foot splinter, local trauma related to carrying soil-contaminated material). A neutrophilic response initially occurs, which may be followed by a granulomatous reaction. Spread occurs through skin facial planes and can involve the bone. Hematogenous or lymphatic spread is uncommon.

CAUSES

• Mycetoma occurs most often in farmers, shepherds, Bedouins, nomads, and people living in rural areas.
• Frequent exposure to penetrating wounds by thorns or splinters is a risk factor.
• Actinomycetoma can be caused by the following:
  

  • Actinomadura madurae
  • Actinomadura pelletieri
  • Streptomyces somaliensis
  • Nocardia species
• Eumycetoma is mainly caused by P boydii (S apiospermum) or Madurella mycetomatis.

EPIDEMIOLOGY

Mycetoma is endemic in Africa, from Sudan and Somalia through Mauritania and Senegal. Other endemic countries include Mexico and India. Mycetoma can also be found in natives of areas of Central and South America and the Middle or Far East. Eumycetoma is more common in areas where the average rainfall is scarce (ie, < 350 mm), whereas actinomycetoma tends to appear in areas with abundant rainfall (ie, >600 mm) and has been described in Southeast Asia.

In Sudanese hospitals, at least 300-400 patients are diagnosed with mycetoma every year. 

SYMPTOMS

• The earliest sign of mycetoma is a painless subcutaneous swelling. Some patients have a history of a penetrating injury at that site.
• Several years later, a painless subcutaneous nodule is observed. After some years, massive swelling of the area occurs, with induration, skin rupture, and sinus tract formation.
• As the infection spreads to contiguous body parts, old sinuses close and new ones open.
• Nearly 20% of patients with mycetoma experience associated pain, usually due to secondary bacterial infection or, less commonly, bone invasion.

1. Initially, subcutaneous swelling is present.
2. In a later phase, a subcutaneous nodule develops.
3. Eventually, massive swelling with induration, rupture of the skin, and formation of sinus tracts occur.
4. Regional lymphadenopathy 

TREATMENT

In the treatment of mycetoma, antibiotic or antifungal therapy should be attempted first and may need to be combined with surgery, especially for eumycetoma lesions in the extremities.

External beam radiotherapy in doses ranging from 3.5-14 Gy has been considered successful treatment in a few selected cases.

Actinomycetomas usually respond better than eumycetomas to medical treatment - the latter often being difficult to treat. Bone involvement complicates clinical management, often leaving surgical amputation as the only treatment option.

• Due to the slow, relatively pain-free progression of the disease, mycetoma is often at an advanced stage when diagnosed.
• Surgical debridement, followed by prolonged appropriate antibiotic therapy for several months is required for actinomycetoma.Combination therapy with trimethoprim-sulfamethoxazole, dapsone and streptomycin has been used. Rifampin has been used in resistant cases.
• Eumycetomas are only partially responsive to antifungal therapy but can be treated by surgery, due to their normally well circumscribed nature. Surgery in combination with azole treatment is the recommended regime for small eumycetoma lesions in the extremities. M. mycetomatis may respond to ketoconazole, P. boydii (S. apiospermum) may respond to itraconazole. Other agents of eumycetoma may respond intermittently to itraconazole or amphotericin.

SOURCE: patient.co.uk
                 emedicine.medscape.com
                  wikipedia,org