Subcutaneous Mycoses (Mycetoma) General Introduction Types of Mycetoma and Causative agent Pathogenesis Clinical manifestation Laboratory Diagnosis Specimen Collection Direct Examination Culture Indetification Treatment

1. SUBCUTANEOUS MYCOSES
(MYCETOMA)
Ankur Vashishtha
Assistant Professor
IIMT University, Meerut

2. SUBCUTANEOUS MYCOSES
• The agents of subcutaneous mycoses usually inhabit the soil.
They enter the skin by traumatic inoculation with contaminated
material and tend to produce the granulomatous lesions in the
subcutaneous tissue.

3. MYCETOMA
• Mycetoma is a chronic, slowly progressive granulomatous infection of the
skin and subcutaneous tissues.
• Clinically, it is manifested as a triad of swelling, discharging sinuses and
presence of granules in the discharge
• Mycetoma is also known as Maduramycosis or Madura foot, as it was
first described in Madurai, South India, by John Gill (1842).

4. Types of Mycetoma and Causative Agents
• Mycetoma can be of two types. It can be caused by either
fungal agents (eumycetoma) or bacterial agents
(actinomycetoma).
1. Eumycetoma
2. Actinomycetoma

5. Agents of Mycetoma and types of grains they produce
Eumycetoma (Fungal agent) Actinomycetoma (Bacterial agent)
1. Black granules
• Madurella mycetomatis
• Madurella grisea
• Exophiala jeanselmei
• Curvularia species
1. White to yellow Granules
• Nocardia species
• Streptomyces somaliensis
• Antinomadura madural
2. White Granules
• Pseuallesceria bydii
• Aspergillus nidulans
• Acremonium species
• Fusarium sopecies
2. Pink to red Geanules
• Actinomadura pelletieri

7. Pathogenesis
• The causative agents enter the skin or subcutaneous tissue from the
contaminated soil, usually by the accidental trauma such as thorn prick or
splinter injury.

8. Clinical Manifestations
Hallmark of mycetoma is presence of clinical triad
consisting of:-
• Tumor like swelling, i.e. tumefaction
• Discharging sinuses
• Discharge oozing from sinuses containing granules.

9. Epidemiology
Mycetoma is endemic in Africa, India, the Central and South America, and
has a non-uniform distribution.
• Overall, actinomycetoma is more common ( 60%) than eumycetoma
(40%) globally, whereas eumycetoma is more common in Africa However,
within a country,

10. Laboratory Diagnosis
Specimen Collection
• The lesions should be cleaned with antiseptics and the grains should be
collected on sterile gauze by pressing the sinuses from periphery or by
using a loop.

11. DirectExamination
• Granules are thoroughly washed in sterile saline; crushed between the
slides and examined.
• Macroscopic appearance of granules such as color, size, shape, texture
may provide important clue to identify the etiological agent

12. • If eumycetoma is suspected: Grains are subjected to KOH mount, which
reveals hyphae of2- 6 μm width along with chlamydospores at margin
• If actinomycetoma is suspected: Grains are subjected to Gram staining
which reveals filamentous grampositive bacilli (0.5-1 μm wide). Modified
acid fast stain is performed if Nocardia is suspected, as it is partially acid
fast

14. Histopathological staining
• H & E Satin
• PAS
• GMS

15. Culture
• For fungal SDA and Bacteriological such Lowenstein Jensen media.
• For fungal:- Inoculated on SDA with antibiotics like chloramphenicol and
gentamicin, and incubated at 25°C, 37°C and 44°C.
• For bacterial:- Inoculate on Blood agar, LJ and SDA tubes.

16. IDENTIFICATION
For Eumycetoma (Fungal agent) For Actinomycetoma (Bacterial agent)
Observation of the growth rate Growth rate
Colony Morphology Colony Morphology
Production of Candida Urease test
Sugar assimilation patterns Tyrosine test

17. Treatment
• Treatment of mycetoma consists of surgical removal of the lesion followed
by use of:
• Antifungal agents for eumycetoma (Itraconazole or amphotericin B for 8-
24 months).
• Antibiotics for actinomycetoma such as (amikacin plus cotrimoxazole).

18. Thank
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