sporotrichosis

Question 1

general

Answer 1

Subcutaneous noduloulcerative lesions
➢ Thermally dimorphic fungus
➢ Sporothrix schenckii
➢ Lives in soil and on plants - Through cuts or scrapes, such as pricks from rose thorns
➢ Sporothrix brasiliensis - Cat-associated
sporotrichosis

Question 2

Specimens

Answer 2

pus, aspirate from nodules, curettage or
swabbing from ulcers

Question 3

microscopy

Answer 3

KOH mount or calcofluor staining - elongated yeast cells
of 3–5 μm in diameter.

Question 4

Histopathological staining (e.g. H and E)

Answer 4

cigar-shaped (sub globose to ovoid) asteroid bodies - central basophilic yeast cells surrounded by radiating extensions of eosinophilic mass, composed of antigen-antibody complexes
➢ Eosinophilic halo - Splendore-Hoeppli phenomenon

Question 5

Culture

Answer 5

SDA and blood agar in duplicate and incubated at 25°C
and 37°C simultaneously

➢At 25°C: mycelial form,
hyphae with conidia arranged in daisy pattern (LPCB)

➢At 37°C: yeast form, moist creamy white colonies which turn brown black in 10–14 days.

Question 6

➢Serology

Answer 6

Latex agglutination test detects serum antibodies in patients with extracutaneous form of the disease,

Question 7

Skin test:

Answer 7

may demonstrate delayed type of hypersensitivity reaction against sporotrichin antigen.