SUBCUTANEOUS
MYCOSIS
INTRODUCTION



Usually follow trauma.
Lesions develop at the site of implantation of
the etiological agent in the subcutaneous
tissue.
Includes – Mycetoma
- Sporotrichosis
- Rhinosporidiosis
- Chromoblastomycosis
- Phaeohyphomycosis
- Lobomycosis
MYCETOMA
(=Maduromycosis=Madura foot)

Mycetoma - clinical syndrome of localized, indolent,
deforming, swollen lesions and sinuses, involving
cutaneous and subcutaneous tissues, fascia, and
bone; usually occurring on the foot or hand) etiologic agent may be fungi or actinomycetes.

Madura foot referring to the first case seen in
Madura region of India which was in the foot of that
patient

Infection is acquired following trauma to the skin by
plant materials from trees, shrubs or vegetation
debris, thus more seen in rural areas (in farmers
walking bare-foot in agricultural land or city parks).

One potential causal agent can be Pseudallescheria
boydii,
a
soil/water
inhabiting
fungus
with
worldwide distribution. However other fungi can be
involved.
MYCETOMA
(=Maduromycosis=Madura foot)

Fungi associated with fungal mycetoma are
opportunistic.

mycotic mycetoma - usually more common in
men (3:1 to 5:1) than in women

usually results from trauma or puncture wounds
to feet, legs, arms and hands (usually on the
feet)

starts
out
as
tumor-like
to
subcutaneous
swelling

ruptures near the surface; infects deeper tissues
including subcutaneous tissues and ligaments
(tendons, muscles and bone are usually spared)

small particles or grains leak out of the lesions -
these represent the yellowish microcolonies
Mycetoma
MYCETOMA
(=Maduromycosis=Madura foot)
 Posttraumatic
chronic inf. of
subcutaneous tissue
 Common in tropical climates
 Causative agents
Saprophytic fungi
(Eumycetoma)
Actinomyces
(Actinomycetoma)
MYCETOMA
Causative agents
 Madurella
mycetomatis
 Pseudallescheria boydii
 Acremonium
 Exophiala jeanselmei
 Leptosphaeria
 Aspergillus
The
common
etiological
agent
in
Saudi
Arabia
and
neighboring countries are: Madurella mycetomatis causes the
majority of the cases with the black grains. It is imperfect
dematiaceous mold with brown colonies and diffused honeycolord pigment.
Madurella grisea: another species of madurella similar to
mycetomatis but with grey colonies
Pseudoallescheria boydii: causes white grain mycetoma. It is
Ascomycetes mold forming cleistothecia and ascospores. The
imperfect of it’s the moniliaceous mold: Scedosporium
apiospermum which forms annelloconidia from annellids.
Synnemata and
conidia
MYCETOMA
Clinical findings
Site(s): Feet, lower extremities, hands
Findings: Abscess formation, draining
sinuses containing granules
Deformities
Dissemination: Muscles and bones
MYCETOMA
Diagnosis
 Clinical
findings are nonspecific
 Identification
of the infecting
fungus is difficult
 Characteristics
of the granule,
colony morphology, and physiological
tests are used for identification
EUMYCETOMA
Treatment
 Surgery
 Antifungal
therapy
Amphotericin B
Flucytosine
Topical nystatin
Topical potassium iodide
(choice of treatment varies
according to the infecting fungus)
SPOROTRICHOSIS




Caused by Sporothrix schenckii, a dimorphic
fungus.
Most common in USA.
Found on plant, thorns & timber
Infection is acquired through thorn pricks or
other minor injuries
Pathogenesis & pathology



Spreads from primary site
to the regional LNs through
lymphatics
Mostly involves upper limbs
Clinical features - Nodules
on the skin, subcutaneous
tissue and in the LNs which
later soften & ulcerate.
Lymphocutaneous sporotrichosis
Laboratory Diagnosis

Specimens – pus, exudate & aspirate from
nodules.
- curettage or swabs from open lesions.
Direct Examination


Gram’s stain – gram+ve, irregularly stained
yeast cells.
CFW – very useful.
Direct examination


Tissues – organisms appear as cigar shaped
bodies (yeast cells) 3-5µ in diameter.
“Asteroid bodies” in the lesion – central
fungus cell surrounded by a refractile
eosinophilic halo, called “ Splendore-Hoeppli”
phenomenon : due to immune complex
deposition around the organism.
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.
Treatment & Prophylaxis

Saturated solution of KI – drug of choice

Oral Ketoconazole or Itraconazole
RHINOSPORIDIOSIS



Caused
by
a
hydrophilic
Rhinosporidium seeberi
protist,
1st identified in Argentina, but majority of cases
occur in India and Srilanka.
High incidence among people who frequently
bath along with domestic animals in ponds,
tanks, lakes
Clinical Features



Chronic granulomatous disease of mucous
membrane.
Characterised by the development of friable
polyps in the nose, mouth or eye.
Miscellaneous forms –
Buccal cavity,vagina,
vulva, penis, urethra
or rectum
Laboratory Diagnosis

Cannot be cultured
Direct Examination

FNAC (fine needle aspiration
Biopsy of lesion, Nasal washing
- Contains sporangia
filled with thousands of
sporangiospores(6-9µ)
embedded in a stroma
of connective tissue &
capillaries
cytology),
Treatment & Prophylaxis



Radical Surgery:- Excision/ Electrocautery
Medical therapy :- not useful
DDS (diaminodiphenylsulfone; widely used)
Recurrence common
CHROMO BLASTOMYCOSIS



Caused by dematiaceous (pigmented) fungi
Commonest fungi - Fonsecaea Species
Phialophora verrucosa
Cladosporium carrionii
Also called as Verrucous dermatitis
Chromoblastomycosis
Clinical features




Soil saprobes enter the skin by traumatic
implantation and lesions develop slowly around
the site of implantation
Warty cutaneous nodules which resembles
flouts of cauliflower - Verrucous dermatitis
Frequently ulcerate
Confined to the subcutaneous tissue of the feet
and lower legs
Laboratory Diagnosis
Direct Examination
1.
Dry crusty material from the surface of the
lesions
KOH w/m –
dark brown, multicellular structures, 5-12μ in
diameter that divide by transverse septation.
-Called sclerotic bodies, medlar bodies, copperpennies bodies or muriform cells
Fonsecaea spp.
Phialophora spp.
Sclerotic bodies - KOH
Sclerotic bodies - tissues
Direct examination
Medlar bodies - characteristic tissue form facilitates survival of organism in host tissues.
2.
Tissue Stains - for Biopsy specimens
HE, Giemsa & Fontana- Masson
- Sclerotic bodies very well seen
Fungal culture - SDA with actidione and
antibiotics
Treatment & Prophylaxis




Responds poorly to available therapies.
Cryotherapy,
Thermotherapy,
therapy,Chemotherapy and Surgery.
Flucytosine (commonly used drug)
Itraconazole, Fluconazole, Terbinafine
*Relapses are frequently seen
Laser
PHAEOHYPHOMYCOSIS

Seen in debilitated & immunodeficient hosts.

Causes subcutaneous & systemic infection.

Caused by dematiaceous fungi. Commonest
genera involved - Alternaria, Bipolaris,
Curvularia, Exophiala, Phialophora, etc.
Cutaneous phaeohyphomycosis of
the forearm caused by Exophiala
jeanselmei.
Cutaneous phaeohyphomycosis
of the face caused by Wangiella
dermatitidis.
Phaeohyphomycosis
Exophiala moniliae
Wangiella dermatitidis
Cladophialophora bantiana
Bipolaris australiensis
Cladosporium cladosporioides
Aureobasidium pullulans
Clinical Features

1.
2.
3.
Clinical types:
Brain abscess caused by Cladosporium
Subcutaneous or intramuscular lesions with
abscess or cysts - single circumscribed
lesion with a central cavity filled with pus
and surrounded by a fibrous wall
Cutaneous lesions
Laboratory Diagnosis


Specimen
Aspirates from cysts
Curetting from plaques, nodules and drained
abscess
Direct Examination
KOH mount
- Pigmented hyphae 3-4µ in dia.
Fungal Culture

SDA with actidione at 25º & 37ºC.
Treatment & Prophylaxis


Local excision for subcutaneous forms
Invasive infections – I.V. AMB +
Flucytosine.
Oral
LOBOMYCOSIS




Caused by Lacazia loboi
(Hydrophilic fungus) : exists
only as yeast cells.
Involves exposed parts
Presence of macule, papule,
keloid, verrucous, nodular
lesions or plaques & tumors.
Lesions are painless with
slight pruritis
Laboratory Diagnosis

•
Direct Examination of curettage / biopsy crushed
a. KOH w / m
b. CFW
- spheroid, yeast - like cells, 5 -12µ
- thick - walled & multinucleate.
- form chain with cells joined by bridges.
c. HE – may show ‘asteroid bodies’
Culture – cannot be cultured
Fontana Masson stain
Treatment & prophylaxis



No effective medical treatment
Complete excision
Cryosurgery.