Sporotrichosis & chromoblatomycosis

1. Sporotrichosis
Chromoblastomycosis
Dr arjun

2. o Deep fungal infections comprise two distinct
groups of conditions,the subcutaneous &
systemic mycoses
o Neither are common,the subcutaneous
mycoses,with some exceptions ae largely
confined to the tropics & subtropics
o Systemic mycoses common among
immunocomprised patients AIDS & receiving
treatment for malignancies

3. o Systemic mycoses may also affect healthy
individuals in the form of primary respiratorry
infections such as histoplasmosis &
coccidioidomycosis
o These fungi are usually dimorphic or exist in a
different morphologic phase(yeast or mold)

5. Subcutaneous mycoses:
o Sporotrichosis
o Mycetoma
o Chromoblastomycosis
o Phaeohyphomycosis
o Lobomycosis
o Rhinosporidiosis
o Subcutaneous zygomycosis

6. Systemic mycoses
o Histoplasmosis
o Blastomycosis
o Coccidioidomycosis
o Paracoccidioidomycosis
o Infections caused by Penicillium marneffei
o Cryptococcosis
o Systemic candidosis
o Zygomycosis
o Cutaneous infection caused by Pneumocystis jiroveci
o Infections caused by Pythium insidiosum
o Protothecosis

7. Subcutaneous mycoses: mycoses of implantation
o are sporadically occurring infections caused by fungi
present in the natural environment, which are
directly inoculated into the dermis or subcutaneous
tissue through a penetrating injury
o As many have long incubation periods, they may be
seen in countries outside the endemic areas in
patients who were originally infected elsewhere

8. o The most common of these infections are
sporotrichosis, mycetoma & chromoblastomycosis.
o phaeohyphomycosis, lobomycosis, rhinosporidiosis
and subcutaneous zygomycosis are rare

9. o rose-pickers disease
o An acute or chronic fungal infection caused by
Sporothrix schenckii.
o There are both cutaneous and systemic forms of
sporotrichosis.
o Sporothrix schenckii is a dimorphic fungus. It occurs
in both temperate and tropical zones
Sporotrichosis

10. o Slender (2-μm) hyphae bear small, oval to pyriform,
hyaline conidia produced along the sides of the
hyphae and sympodially at the ends of delicate
conidiophores arising at right angles from the
hyphae.
o The arrangement of the conidia at the apex of the
conidiogenous cell is often described as palmate or
flower-like, with each conidium attached by a
denticle to the small vesicle

12. • The incidence is highest in the autumn and first half
of the winter (high humidity and temperatures
between 16 and 22°C) .
• These conditions favour saprophytic growth of S.
schenckii.
• Sporotrichosis is rare in semiarid areas. The fungus
grows on decaying vegetable matter, for example
the timber in mines

13. • It has been shown that the timber harbours the
fungus before being taken underground, and that
the source is probably the soil in the vicinity of the
mines.
• S. schenckii could be recovered from the feet of
mine workers who did not have sporotrichosis.
• also occur in other groups occupationally exposed
to the organism, such as workers using straw as
packing material, forestry workers,florists or
gardeners.

14. • In most cases of cutaneous sporotrichosis, the
portal of entry into skin or mucous membrane by
trauma, as in a minor puncture wound caused by a
thorn or to a splinter, or perhaps an insect bite.
• Sporotrichosis is not contagious, although
transmission has been recorded from cats.

15. • Adult males are, by their occupation, most exposed
to the risk of infection.
• Systemic sporotrichosis is rare, and the portal of
entry is thought to be the lung in these cases.

16. • Clinical features:
• The main clinical varieties of sporotrichosis are the
cutaneous and the systemic forms.
• In turn cutaneous sporotrichosis is normally divided
into two main types, the lymphangitic and fixed
forms.
• occasionally atypical varieties such as mycetoma-
like or cellulitic forms may occur

17. • Lymphangitic:
• The most common type of sporotrichosis is the
localized lymphatic variety, which follows the
implantation of spores in a wound.
• usually occurs on exposed skin, often on the upper
extremity, and is known as lymphangitic
sporotrichosis.
• A nodule or pustule forms, which may break down
into a small ulcer

18. • Untreated the disease usually follows a chronic
course, which is characterized by involvement of
lymphatics from the draining area, a chain of
lymphatic nodules develops.
• New nodules appear at intervals of a few days.
These soften and ulcerate, and are connected by
tender lymphatic cords.
• A thin purulent discharge may come from the
primary lesion and the earliest lymphatic nodules.

19. • As the disease becomes chronic, the regional
lymph nodes become swollen and may break
down. The primary lesion may heal
spontaneously leaving the lymphatic nodes
enlarged

22. • Fixed type:
• where the pathogen remains more or less localized
at the point of inoculation, is less common.
• The lesions may be acneiform, nodular, ulcerated or
verrucous; the latter form is occasionally very
extensive.
• Less commonly, there may be infiltrated plaques or
red scaly patches. An ulcer may be gummatous or
may simulate an epithelioma.

24. o The plaques may suggest leishmaniasis or
tuberculosis.
o It is thought that this variety may reflect a high
degree of immunity on the part of the patient.
o The variable morphology of this type is notable

25. o The less common systemic form probably follows
inhalation, and presents either with local
pulmonary disease or focal or widely disseminated
lesions in the joints, meninges and skin.
o There is some evidence that systemic sporotrichosis
occurs in patients with some defect in host defence,
such as alcoholics.
o Where sporotrichosis has been reported in AIDS
patients, the lesions have usually been widespread
and have affected internal organs as well as the
skin.

26. o contrast to the cutaneous variety, which occurs in
perfectly healthy individuals.
o Sporotrichosis in AIDS patients, the lesions have usually
been widespread and have affected internal organs as
well as the skin.
o In the systemic type, which is rare, ulcerated nodules
may develop anywhere on the body or mucous
membranes, and visceral lesions may occur
o If untreated, this type is fatal but systemic
sporotrichosis is exceedingly rare

27. Lab diagnosis:
• S. schenckii is very rarely present in quantity in
infected tissues, and direct microscopy of clinical
material is of little or no value in confirming a
diagnosis.
• Fluorescent antibody techniques have been
successfully employed in locating the pathogenic
phase in vivo.
• The fungus grows readily on common agar media.

28. Cigar bodies represent the elongated yeast like form of the fungus
and when these yeast forms are surrounded by eosinophilic
hyaline ray like processes they are referred to as ‘sporothrix
asteroid’,usually seen in the centre of suppurative granulomas

29. • The colonies are leathery, moist and initially white
or cream with a wrinkled surface.
• As the colonies age, they may become progressively
darker until they are brown or black

30. Physiological tests:
• To confirm the identification, it is essential to
convert this thermally dimorphic fungus to the
yeast phase, as fungi that are non-pathogenic and
morphologically very similar may be isolated as
contaminants.
• This is best achieved on brain–heart infusion agar
supplemented with sheep’s blood and incubated at
37°C. The yeasts are typically oval or cigar-shaped

31. Treatment:
• Localised lymphangitic:
• Potassium iodide in large oral doses is effective in
the localized types, and should be continued for 3–
4 weeks after clinical cure.
• It is cheap and effective, although side effects are
common.(hypersalivation & nausea)
• A recommended schedule is five drops initially,
increasing to 4–6 mL of saturated potassium iodide
three times daily.

32. • If unresponsive, Itraconazole 100–200 mg/day or
terbinafine 250 mg/day are both effective and well
tolerated or iv amphotericin B
Systemic form:
• Itraconazole 100–200 mg/day or terbinafine 250
mg/day
• intravenous amphotericin B may also be helpful

33. • In all cases treatment is continued for at least
1 week after clinical resolution
• the local application of heat may produce
recovery in some patients.

34. Differential diagnosis:
• Mycobaterial infections
• Leishmaniasis
• Mycobacterium marinum infection (fish-tank
granuloma) may closely resemble lymphangitic
sporotrichosis
• Primary cutaneous nocardia infections

35. Chromoblastomycosis
• Chromomycosis
• Verrucous dermatitis
• A chronic fungal infection of the skin and
subcutaneous tissues caused by pigmented fungi,
which produce thickwalled single or multicelled
clusters (sclerotic or muriform bodies) in tissue
• characterized by the production of slowgrowing
exophytic lesions, usually on the feet and legs

36. • Chromoblastomycosis is caused by several fungi,
the most common :
Phialophora verrucosa
Fonsecaea pedrosoi
F. compacta
Cladophialophora carrionii
Rare causes
Rhinocladiella aquaspersa
The causative fungi have been isolated from wood & soil, and the infection usually
results from trauma, such as a puncture from a splinter of wood. The condition is
usually found in rural communities

37. • All these fungi are named according to the
dominant form of conidiation
• Phialophora verrucosa
• Microscopy: dominant form of conidiation is the
production of flask-shaped phialides with a
pronounced dark collarette at the apex. These are
produced laterally or terminally
• hyaline thin-walled elliptical conidia are produced
at the tip of the phialide in basipetal succession

38. • Fonsecaea pedrosoi
• Microscopy: dominant form of conidiation is
sympodial with the conidia confined to the upper
part of the cell.
• The brown single-celled conidia are produced on
short denticles and may in turn produce secondary
conidia in a similar manner.
• Conidia produced by acropetal budding

39. Clinical features:
• The lesions are usually found on exposed sites
particularly the feet, legs, arms, face and neck.
• A warty papule slowly enlarges to form a hypertrophic
plaque.
• In some lesions, the plaque is flat and expands slowly
with central scarring.
• The early lesion may occasionally be an ulcer.
Eventually, after months or many years, large
hyperkeratotic masses are formed, and these may be as
large as 3 cm thick.

40. • Secondary ulceration may occur
• The lesion is usually painless unless the presence of
secondary infection causes itching and pain.
• Satellite lesions are produced by scratching, and
there may be lymphatic spread to adjacent areas.

41. • Haematogenous spread has occurred but is
rare, and brain abscesses have been
described.
• Secondary infection may eventually lead after
several years to lymphatic stasis with the
production of elephantiasis.
• Some forms of the infection produce
psoriasiform lesions. Squamous carcinomas
may develop in chronic lesions

45. • Lab diagnosis:
• Irrespective of species, the pathogen can be seen in
biopsy sections as deeply pigmented, thick-walled
muriform or sclerotic cells.
• Occasionally, in superficial skin scrapings from the
surface of the lesions, pigmented hyphae rather
than sclerotic cells are seen.
• Multiplication in vivo is by fission rather than
budding, and this results in the production of single,
two- or multiple-celled clusters.

46. H&E stained section showing characteristic dark brown
sclerotic cells which divide by binary fission and not by
budding. Note all agents of chromoblastomycosis form
these sclerotic bodies in tissue.

47. Culture:
• colonies of all species are dark grey–green to black
and velvety or downy, with a black reverse.
• Three forms of conidial production are observed in
the most common agents of infection:
acropetal budding
production of phialides
sympodial conidiation

48. Treatment:
• Itraconazole (100–200 mg daily) or terbinafine (250
mg daily) is often successful, although responses to
both are thought to be better if the causative
organism is C. carrionii .
• Flucytosine used on its own or combined with
amphotericin B may also be effective, but
resistance to flucytosine may develop if used alone

49. • Other approaches to treatment:
cryotherapy or the local application of heat
• The use of surgery is contentious; in larger plaques
there is a risk in pursuing this approach as satellite
lesions may develop around the excision site
• Surgery is really only indicated in very small lesions
combined with chemotherapy.

50. Differential diagnosis:
blastomycosis (by the absence of a sharp border containing minute
abscesses and also the absence of pulmonary lesions )
cutaneous tuberculosis
leishmaniasis
syphilis
yaws

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