Mycetoma

Question 1

What are the clinical forms of mycetoma and their causative organisms?

Answer 1

• Eumycetoma (true fungi) - variety of fungi (e.g. Madurella mycetomatis)
• Actinomycetoma (bacterial) - Actinomycetes

Question 2

How can eumycetoma be differentiated from actinomycetoma?

Answer 2

Actinomycetes
* Gram-positive organisms
* Branching filaments whose width is generally less than 1 mm
* Actinomyectomas are more diffuse
* Smaller white to yellow colored grains

Eumycetoma
* Fungal hyphae stain with special fungal stains (periodic acid–Schiff (PAS) or methenamine silver)
* Usually more than 2 mm in diameter
* Chlamydospores may also be seen
* Eumycetomas are better circumscribed with a palpable edge
* Larger black or white colored grains visible

Question 3

What’s the geographic distribution of mycetoma?

Answer 3

Tropical areas 18N-18S
* India
* Sudan

Question 4

How are mycetoma infections acquired?

Answer 4

Inoculated through skin via a thorn prick

Question 5

What are clinical clues to mycetoma?

Answer 5

Mycetoma
* Barefoot farmers in tropical areas
* Painless swelling usually of foot
* After several years, nodules form in the skin and break down to form discharging sinuses from which pus and coloured fungal grains emerge
* No systemic signs unless there is secondary infection
* Chronic, slow spread

Question 6

How is mycetoma diagnosed?

Answer 6

• Colour, size, and consistency of grains gives provisional diagnosis
• Fungal stains of biopsies
• Culture required for confirmation

Question 7

What’s the treatment for mycetoma?

Answer 7

Actinomycetoma
* Streptomycin combined with co-trimoxazole

Eumycetoma
* Itraconazole, OR
* Ketoconazole