Subcutaneous Mycoses

1. Subcutaneous Mycoses

2. These are caused by fungi that grow in soil and on vegetation and are introduced into subcutaneous tissue through trauma.

3. Subcutaneous Mycoses • Mycetoma • Chromoblastomycosis • Phaeohyphomycosis • Sporotrichosis • Lobomycosis • Rhinosporidiosis

4. MYCETOMA(Maduromycosis=Madura foot) • Post-traumatic chronic infection of subcutaneous tissue. • Characterized by draining sinuses, granules and tumefaction. • Caused by a number of different fungi and actinomycetes. • First case seen in Madura region of India.

5. Distribution • World-wide • Most common in bare-footed populations living in tropical or subtropical regions

6. Source of infection: soil • Mode of infection : trauma • Infection is acquired following trauma to the skin by plant materials from trees, shrubs or vegetation debris. • More seen in rural areas (in farmers, walking bare-foot in agricultural land or city parks).

7. Feet are the most common site for infection and account for at least two-thirds of cases. • Other sites include the lower legs, hands, head, neck, chest, shoulder and arms.

8. Causative agents • Saprophytic fungi (Eumycetoma) • Actinomyces (Actinomycetoma)

9. Eumycetoma • Madurella mycetomatis • Pseudallescheria boydii • Acremonium • Exophiala jeanselmei • Leptosphaeria

10. Clinical findings Site(s): Feet, lower extremities, hands Findings:Abscess formation, draining sinuses containing granules Deformities Dissemination: Muscles and bones

11. Most cases start out as a small hard painless nodule which over time ulcerate to discharge a viscous, purulent fluid containing grains. • Spread to surrounding area. • Spares nerve and tendons.

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19. Diagnosis • Clinical findings : • Triad- tumefaction, multiple discharging sinuses, granules. • Characteristics of the granules

20. Laboratory diagnosis: Clinical specimen: • Tissue biopsy or excised sinus • Serosanguinous fluid containing the granules Methods: • Macroscopic examination of the granule • 0.5 – 2mm diameter • Bacterial- white granule (rarely red) • Eumycetoma- black or white

21. 2. Direct Microscopy • Serosanguinous fluid containing the granules examined using either 10% KOH and Parker ink or calcofluor white mounts. • Tissue sections stained using H&E, PAS digest, and Grocott's methenamine silver (GMS).

22. Tissue section showing blacked grained eumycotic mycetoma caused by Madurella mycetomatis

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24. 3. Culture Media used: SDA

25. Pseudallescheria boydii

26. 369 M. mycetomatis

27. Treatment: Combining miconazole and surgery may prove useful in effectively treating the disease.

28. Sporotrichosis • Primarily a chronic mycotic infection of the cutaneous or subcutaneous tissues and adjacent lymphatics characterized by nodular lesions which may suppurate and ulcerate. • Infections are caused by the traumatic implantation of the fungus into the skin, or very rarely, by inhalation into the lungs. • First case presented with the clinical picture of sporotrichosis was recorded by Schenck in 1898 from Johns Hopkins Hospital.

29. Etiologic agent - Sporothrix schenckii • This fungus is a dimorphic fungus. • At room 25 degree, it grows as a mold producing branching septate hyphae + conidia & in tissues or at 37 degree, it grows as small budding yeast cells. • This fungus lives on plants, grass, trees and rose thorns.

30. …..Rose gardener’s disease Sporothrix schenkii infects the body by; Rarely, inhalation Traumatic inoculation Pulmonary lesion Lymphocutaneous sporotrichosis Fixed cutaneous sporotrichosis

31. Fungus enters through scratches from thorns or splinters, cuts while handling potting soil, sphagnum moss, or grass • Distribution: World-wide particularly tropical and temperate regions. • In India, it is prevalent in sub-Himalayan areas.

32. Pathogenesis • The conidia or hyphal fragments are introduced into the skin by traumatic inoculation usually by rose thorns. • So, this disease is an occupational risk to gardeners and agricultural workers.

33. Clinical types • Lymphocutaneous sporotrichosis • Fixed cutaneous sporotrichosis • Mucocutaneous sporotrichosis • Disseminated sporotrichosis • Pulmonary sporotrichosis

34. The first sign of disease is the appearance of a small, hard, nontender subcutaneous nodule. • As the disease progresses – involves adjacent lymphatics.Nodulo-ulcerative secondary lesions • Lymphocutaneous sporotrichoisis - 75% of all cases.

35. Secondary spread to articular surfaces, bone and muscle is not infrequent, and the infection may also occasionally involve the central nervous system, lungs or genitourinary tract. • Granulomatous raection + pyogenic.

36. The initial lesion is a granulomatous nodule that will ulcerate and become necrotic. • Multiple subcutaneous nodules occur along the lymphatic vessels.

37. In endemic areas such as Mexico, South Africa and Japan, population has some immunity to sporothrix so they develop fixed cutaneous sporotrichosis in which the patient has only single non lymphatic nodule which is limited and non progressive.

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43. Lab -diagnosis Specimen: • Biopsy • Exudate from the lesion

44. LaboLab-ratry diagnosis Methods • Direct microscopic examination: • Yeasts are seen in tissue sections stained with Gomori methenamine silver which stain cells black or periodic acid Schiff which stain cells red. • Yeast cells are round, fusiform or cigar shaped (1-3 X 3-10 µm).

45. Budding yeast often irregularly-shaped to broadly elliptical (cigar bodies).

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49. Another structure termed asteriod body is often seen especially in endemic areas. In H&E sections, asteriod body is a central basophilic yeast cell surrounded by eosinophilic radiating extensions which are Ag/Ab complexes

50. Fungus is diphasic, and will convert from a filamentous phase to a yeast phase when grown at a higher temperature (37°C). • Filamentous phase is hyaline, and produces delicate conidiophores and conidia.