Mycetoma, also called Madura foot and Actinomycetoma, is caused by penetrating wounds. Mycetoma causes soft tissue swelling (often painless) and sinus tracts, usually of the foot, with draining visible granules 0.2 to 5 mm in diameter (no magnification needed).
CASES/YEAR
500 (US); 10,000 (Global)
OTHER NAMES
Madura foot; Eumycetoma; Actinomycetoma;
INCUBATION
Months to years; [CCDM]
INITIAL SYMPTOMS
Soft tissue swelling (often painless) and sinus tracts, usually of the foot, with draining visible granules 0.2 to 5 mm in diameter (no magnification needed); [PPID, p. 3143]
PRECAUTIONS
No person-to-person transmission but from penetrating wounds; [CCDM, p. 424]
COMMENTS
This chronic infection is often localized to a single foot. The two types of mycetoma are: 1.) Eumycetoma caused by Madurella spp. (black grains), Scedoisporium apiospermium (white grains), and others; and 2.) Actinomycetoma caused by Nocardia spp. and others (white, yellow, brown, red, or pink grains). The organisms that cause mycetoma are fungi (eumycetoma) and aerophilic filamentous bacteria (actinomycetoma) that live in the soil and on plants. They are introduced into the body by penetrating trauma. The disease is a local infection without systemic symptoms. Affected are skin, subcutaneous tissues, and sometimes bone. Osteomyelitis and secondary infection with sepsis can occur in advanced cases. Immune deficiency does not appear to be a risk factor. [PPID, p. 3141-5] The regional lymph nodes are rarely involved (2-5% of cases). [Cohen, p. 1720] The mycetoma triad is painless swelling, sinuses, and grains. The skin lesions are nodules, ulcers, or draining sinus tracts. Enlarged regional lymph nodes are common. A localized disease, mycetoma does not cause constitutional symptoms except from secondary bacterial infections. The differential diagnosis includes: Kaposi's sarcoma, fibroma, malignant melanoma, foreign body granuloma, and chronic osteomyelitis (tuberculosis). [Guerrant, p. 565-8, 969] See "Phaeohyphomycosis."
DIAGNOSTIC
Clinical triad: swelling, sinus tracts, and drainage (grains); Microscopic examination and culture of a grain; Fungi produce 2-5 um diameter hyphae; Actinomycetes produce 0.5-1 um diameter filaments. [PPID. p. 3143-4]
SCOPE
Global, but most common in tropical and subtropical areas and in areas where farmers and laborers do not wear shoes; Causative agents vary with region; [PPID, p. 3142]
SIGNS & SYMPTOMS
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H anemia
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H lymphadenopathy
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S entry wound with lymph nodes
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S papules or plaques
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S pustule
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S skin blister or vesicles
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S skin or subcutaneous nodule
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S ulcer of skin
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*arthritis
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*osteomyelitis
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*weight loss
ENTRY
Skin or Mucous Membranes (Includes Conjunctiva)
SOURCE
Soil or Dust (Ingesting or Inhaling)
RISK FACTORS
- Walk barefooted in contaminated soil
TREATMENT
Actinomycetoma, but not eumycetoma, can be successfully treated with a combination of antibiotics. [Guerrant, p. 568]
REFERENCES FOR CASES/YEAR
1. (US) No data found; Assume same cases/yr as Mucormycosis;
2. (Global) 20 X US cases/yr;