Subcutaneous Mycoses

Question 1

Causative agents of:

Chromoblastomycosis
Chromomycosis

Answer 1

Dematiaceous fungi
(having melanin or melanin-like pigment in the wall of their hyphae and/or spores)

✅ Phialophora verrucosa
✅ Fonseccae pedrosoi
✅ Rhinocladiella aquaspersa
✅ Fonseccae compactum
✅ Cladophialophora carrionii

Question 2

Mycetoma causative agents

Answer 2

🩵Pseuddallescheria boydii
🩵Acremonium falciforme
🩵Madurella mycetomatis
🩵M. Grisea
🩵Exophiala jeanselmi

Question 3

Sporotrichosis causative agent

Answer 3

Sporothrix schenkii

Question 4

Rhinosporidiosis causative agent

Answer 4

Rhinosporidium seeberi

Question 4

Phaeohyphomycosis causative agents

Answer 4

🩵 Exophiala spp
🩵 E. dermatitidis

Question 5

Lobomycosis causative agent

Answer 5

Lacazia loboi

Question 6

Chronic, slowly progressive granulomatous infection of skin & subcutaneous tissues with the involvement of underlying fascia & bones commonly affecting the extremities.

Answer 6

MYCETOMA

Question 7

AKA Maduramycosis or Madura foot.

Answer 7

MYCETOMA

Question 8

Two (2) Classification of Mycetoma

Answer 8

̈ Based on the causative agent
̈ Based on the colour of grains

Question 9

Colour of grains in Mycetoma of various etiology

Answer 9

White to yellow
Brown to black
Red

Question 10

Brown to black mycetoma

Answer 10

Madurella mycetomatis
Madurella grisea
Exophiala jeanselmei

Question 10

White to yellow grains Mycetoma

Answer 10

Pseudollescheria boydii
Acremonium falciforme

Question 11

Red grains mycetoma

Answer 11

Actinomadura madurai

Question 12

Common among field workers, famers - prone to thorn prick injury & trauma.

Answer 12

Mycetoma

Question 13

NOTE:

🩵Entry of pathogen into the injured site, mostly foot.

🩵Formation of multiple sinuses on the surface discharging viscid, seropurulent fluid containing granules or grains which are microcolonies of the causative agent.

Answer 13

🐈

Question 14

Mycetoma Triad

Answer 14

🩵Tumefaction - tumor like swelling

🩵Multiple draining sinuses

🩵Presence of grains or granules in sinuses.

Question 15

Under microscopy on direct examination using KOH mount. A 2-6μ, wide interwoven hyphae with large, swollen cells (chlamydospores) at the margin of the lesion was seen.

What disease can the causative agent cause?

Answer 15

Mycetoma

Question 16

SPOROTRICHOSIS causative agent

• Associated with a variety of plants grasses, trees, sphagnum
  moss, rose bushes

Answer 16

Sporothrix schenckii ( a dimorphic fungi)

Question 17

Caused by thorn pricks or other minor injuries. ̈ Mostly involves upper limbs

Answer 17

SPOROTRICHOSIS

Question 18

Pathogenesis & pathology: Give the causative agent and associated disease

– Clinical features - Nodules on the skin, subcutaneous tissue and in the LNs which later soften & ulcerate.

– Pyogranulomatous reaction

– Elicit delayed skin test – “sporotrichin”
Lymphocutaneous sporotrichosis

Answer 18

🩵 Sporothicosis infection
🩵 Sporothrix schenckii

Question 19

Direct Examination

• organisms appear as cigar shaped bodies (yeast cells) 3-5μ in diameter.

Answer 19

🩵 Sporothicosis infection
🩵 Sporothrix schenckii

Question 20

Appears as “Asteroid bodies” in the lesion: central fungus cell surrounded by a refractile eosinophilic halo, called?

Answer 20

“ Splendore-Hoeppli” phenomenon

• due to immune complex deposition around the rganism.

Question 21

Note:

🧫Sprotrichosis: Culture

̈ Inoculated on 2 sets of SDA, BHIA
̈ Incubated at 25°& 37°C ̈ Smear from Culture

— septate hyphae - very thin & carry flower like clusters of small conidia on delicate sterigmata

Answer 21

🩵

Question 22

RHINOSPORIDIOSIS causative agent

Answer 22

Rhinosporidium seeberi

Question 23

High incidence among people who frequently bath along with domestic animals in ponds, tanks, lakes

Answer 23

RHINOSPORIDIOSIS caused by Rhinosporidium seeberi

Question 24

🐈 Characterised by the development of friable polyps in the nose, mouth or eye. 🐈 Chronic, recurrent granulomatous disease of mucous membrane. -Miscellaneous forms – Buccal cavity,vagina, vulva, penis, urethra or rectum

Answer 24

RHINOSPORIDIOSIS caused by Rhinosporidium seeberi

Question 25

Direct Examination for Rhinosporidium seeberi (cannot be cultured)

Answer 25

🐈FNAC, 🐈Biopsy of lesion 🐈Nasal washing

Question 26

Rhinosporidiosis: Treatment & Prophylaxis

Answer 26

🐈Radical Surgery:- Excision/ Electrocautery ̈ Medical therapy :- not useful (Recurrences common)