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.

12. 361
361. Diagrammatic sketch of mycetoma of the foot showing the formation of suppurating abscesses and draining sinuses

13. 362. Actinomycotic mycetoma showing numerous draining sinuses
362. Actinomycotic mycetoma showing numerous draining sinuses. There is destruction of bone, distortion of the foot, and hyperplasia at the openings of the sinus tracts. (Courtesy John Rippon U.S.A.).

19. Diagnosis Clinical findings : Characteristics of the granules
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

23. 367
367. Haematoxylin and eosin (H&E) stained tissue section showing black grained eumycotic mycetoma caused by Madurella mycetomatis. (Courtesy Dr O'Keefe, School of Public Health and Tropical Medicine, N.S.W.).

24. 3. Culture
Media used: SDA

25. Pseudallescheria boydii

26. 369
M. mycetomatis
369. Microscopic morphology of M. mycetomatis showing phialides (rarely seen as most isolates are sterile) Although most cultures are sterile, two types of conidia ion have been observed, the first being flask-shaped phialides that bear rounded conidia, the second being simple or branched conidiophores bearing performs conidia (3-5um) with truncated bases. The optimum temperature for growth of this mould is 37OC.

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. 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.
Pathogenesis

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.

38. 433
433. Lymphocutaneous sporotrichosis showing typical elevated subcutaneous nodules developing along the regional lymphatics of the forearm. (Courtesy Professor D. Weedon, Brisbane, Qld.).

39. 434
434. Lymphocutaneous sporotrichosis showing more advanced, ulcerating lesions developing along the lymph system of the forearm. (Courtesy Professor D. Weedon, Brisbane, Qld.).

40. 435. Lymphocutaneous sporotrichosis showing more advanced, ulcerating lesions developing along the lymph system of the forearm. (Courtesy Professor D. Weedon, Brisbane, Qld.).

41. 436. Fixed cutaneous verrucous-type sporotrichosis of the wrist and hand, looking remarkably similar to chromoblastomycosis. (Courtesy Professor D. Weedon, Brisbane, Qld.).

42. 437
437. Fixed cutaneous verrucous-type sporotrichosis of the wrist and hand, looking remarkably similar to chromoblastomycosis. (Courtesy Professor D. Weedon, Brisbane, Qld.).

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).

47. 438
438. Section from a fixed cutaneous lesion on the face of a child with sporotrichosis showing round Periodic Acid-Schiff (PAS) positive yeast-like cells, one with an elongated bud. Sporothrix schenckii is a dimorphic fungus and this is the typical parasitic or yeast-like form seen in tissue. (Courtesy Professor D. Weedon, Brisbane, Qld.).

48. 441
441. Microscopic morphology of the parasitic or yeast form of Sporothrix schenckii when grown on brain heart infusion agar containing blood and incubated at 370C. Note budding yeast cells.

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. 

51. Culture:
It is the most reliable method of diagnosis of sporotrichosis.
Culture is done on SDA with antibiotics at 25 degree (colonies are black and shiny then become wrinkled and fuzzy with age).

52. 439. Sporothrix schenckii on Sabouraud's dextrose agar grown at 25oC colonies are moist and glabrous, with a wrinkled and folded surface. Pigmentation may vary from white to cream to black

53. Serology: latex agglutination test.
Under the microscope: hyphae are seen bearing clusters of oval conidia (2 – 4 µm) at the tip of slender conidiophore resembling daisy.
-- Flower like pattern
If the plate is incubated at 37 degree, it will convert to a yeast culture.
Serology: latex agglutination test.

54. 440
440. Microscopic morphology of the saprophytic or mycelial form of Sporothrix schenckii when grown on Sabouraud's dextrose agar at 25oC. Note clusters of ovoid conidia produced sympodially on short conidiophores arising at right angles from the thin septate hyphae.

56. Treatment
Oral potassium iodide in milk.
Itraconazole.
Amphotericin B in systemic infections.

57. Lobomycosis or Lobo disease
Caused by Loboa loboi (yeast-like organism that has never been cultured)
Disease is chronic, localized, subepidermal infection characterized by the presence of keloidal, verrucoid, nodular lesions
Frst describe in patient known as Jorge Lobo
Found in humans and dolphins.
Chains of yeast cells form in tissue
Common in Amazon natives

59. Phaeohyphomycosis
Characterized by the presence of brown pigmented fungal elements caused by a number of different fungal species
The fungi are usually pigmented dark brown to hyaline
In rare instances infections may become invasive systemic (invading various organs) and/or  cerebral.
Distribution: World-wide

60. Cutaneous phaeohyphomycosis of the forearm caused by Exophiala jeanselmei.
400. Clinical slide showing cutaneous phaeohyphomycosis of the face caused by Wangiella dermatitidis. (Courtesy of Dr. J.W. Rippon, University of Chicago, USA).
Cutaneous phaeohyphomycosis of the face caused by Wangiella dermatitidis.

61. Aetiological Agents: Various dematiaceous hyphomycetes ;
Cladophialophora bantiana
Curvularia sp.
Wangiella dermatitidis
Bipolaris sp.
Alternaria sp.
Exophiala jeanselmei.

62. Exophiala moniliae
Wangiella dermatitidis

63. Cladophialophora bantiana
Cladosporium cladosporioides
Bipolaris australiensis
Aureobasidium pullulans

64. In diagnosis, materials from cysts, nodules, abscesses and other infected tissues may be examined under the microscope directly with 10% KOH.  The fungi are usually pigmented dark brown to hyaline.
Treatment usually involves surgical excision of fungus and treatment with antifungal drugs (amphotericin B, 5-fluorocytosine, ketoconazole, or another imidazole).

65. Chromoblastomycosis - chromomycosis or verrucous dermatitis
Slowly progressive granulomatous infection, characterized by the formation of verrucoid (rough), warty, cutaneous nodules, which may be raised 1-3 cm above the skin surface.  The roughened, irregular, pedunculated vegetations often resembles the florets of cauliflower.
Found primarily in the tropics or subtropics

66. Aetiological Agents: Fonsecaea pedrosoi
Phialophora verrucosa (identical to Cladophora americana which causes bluing of lumber)
These fungi are collectively dematiaceous fungi, because their conidia or hyphae are dark-colored, either gray or black.

67. Soil-inhabiting fungi
Common in tropics or subtropics
Fungi found growing on plant debris, wood, soil.
Susceptibility enhanced by going barefoot or wearing sandals
Found almost exclusively in laborers
Enters hand or feet after trauma

68. Chromoblastomycosis

69. Red or violet color on skin may resemble a ringworm lesion
Develops into a verrucous lesion
Pruritus (itchiness) and papules may develop
Fungus gets under the skin (produces bumps)
Bumps may block lymphatic system and cause elephantiasis

70. Sometimes bacterial infection may enter and cause a secondary infection
Rarely this fungus spreads to other areas of the subcutaneous tissue.
Potentially may spread to brain (life-threatening in that case)

71. Laboratory diagnosis Microscopy Culture Specimen: Biopsy tissue
Hematoxylin stain - look for fungal cells scattered among skin cells
Colonies of fungi are dark or blackish

72. Two species implicated in this mycosis - each may produce several spore types
Fonsecaea pedrosoi - Cladosporium type and Rhinocladiella type of conidiation
Phialalophora verrucosa - Phialophora type (flowers in the vase conidiation)

73. Fonsecaea spp.

74. Phialophora spp.

75. Treatment
Usually not fatal or necessarily painful
No really good cure
Surgical excision, electrodesiccation, or cryosurgery are useful in early stages of disease
Thiabendazole - shows promise (given orally and on skin mixed with dimethyl sulfoxide [DMSO] - to deliver drug) - experimental drug
Itraconazole shows promise in clinical trials.

76. Rhinosporidiosis
A chronic granulomatous disease characterised by the production of large polyps, tumours, papillomas, or wart-like lesions.
It is an infection of the mucocutaneous tissue.
The nose is the most commonly affected site caused by Rhinosporidium seeberi

77. Causative agent: Rhinosporidium seeberi
yet unisolated and unclassified fungus.
Common in India, Ceylon, the Middle East
Males account for 70-90% of cases
Eye infections seem to be more common in women
Nasal, ocular, and other mucocutaneous regions may show signs of disease manifested as polyps and tumors

78. In tissue, the fungus produces spherules that possess a thick wall;  endospores are contained within.

79. 431
431. Numerous spherules of varying sizes typical of rhinosporidiosis.

82. Treatment:
Surgery
Dapsone