60 year old female. Histopathologic Diagnosis of Infections. 60 year old female. Dirk Elston MD

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1 Histopathologic Diagnosis of Infections 60 year old female Found an 18 year old bottle of eye drops in her medicine cabinet Dirk Elston MD Professor and Chairman Department of Dermatology and Dermatologic Surgery Medical University of South Carolina 60 year old female Found an 18 year old bottle of eye drops in her medicine cabinet Decided to use them Pseudomonas sepsis 1

2 Pseudomonas Sepsis Pseudomonas endophthalmitis Unresponsive to systemic antibiotics Globe removed Survived sepsis after surgery and aminoglycoside therapy 18 year old male Unresponsive tinea pedis Secondary Syphilis with Prozone Phenomenon RPR negative 1:64 dilution positive 2

3 50 y.o. ice cream man Motor vehicle accident New fungal lesion 3

4 Zygomycete Infection Hyperglycemia predisposes to invasion Rapid vasculotropic invasion Surgical debridement Posaconazole New Antifungals Caspofungin (echinocandin) Candida and Aspergillus Voriconazole (triazole) Candida, Aspergillus, Scedosporium and Fusarium Posaconazole Zygomycetes Stains poorly with fungal stains Often stains well with tissue Gram stain 22 week gestation infant with bedsores Ventilator dependent Sores noticed on back / buttocks 4

5 Morphologic Diagnosis Thick walled, irregular, septate hyphae with prominent bubbly cytoplasm Phaeohyphomycosis: Surgery/antifungal 5

6 Confirmation Search for pigmented hyphae Fontana-Masson stain for melanin Black Molds Bipolaris species Phaeohyphomycosis Superficial (tinea nigra) Phaeomycotic cyst Immunocompetent (Phialophora, Exophiala) Invasive Immunosuppressed (Bipolaris) 6

7 Phaeohyphomycosis Begins as skin infection Can disseminate systemically Grows slowly in culture Initial therapy must be based on appearance in tissue sections Phaeohyphomycosis As a group, highly resistant to amphotericin Respond best to massive doses of itraconazole Possibly excellent synergism with terbinafine/fluconazole Liposome-encapsulted amphotericin B Phaeohyphomycosis Aspergillosis Debridement is essential part of therapy Curative in localized infections Reduces fungal burden in disseminated cases Fusariosis 7

8 Fusarium Zygomycete Phaeohyphomycosis Aspergillosis Phaeohyphomycosis Fusariosis Phaeohyphomycosis A Word of Caution Fusariosis Many fungi contain melanin Fontana positivity must be interpreted in the context of the fungal morphology 8

9 7 year of female 7 cm mass on scalp with draining sinus tracts Microsporum canis In foster care Adopted a stray kitten 100 year old man Lesion on the arm Case donated by Antoinette Hood, MD 9

10 Comatose, febrile patient Recent cardiac catheterization New murmur Echocardiogram and repeated blood cultures negative 10

11 Janeway lesion Osler s nodes: Tender pink papules SBE Janeway: Non-tender, angular infarct ABE Transesophageal echo: vegetation Lessons learned Lab tests and echocardiograms can lie Dermatology is truth 5 year old female Multiple subcutaneous nodules 11

12 Histoplasma capsulatum Macroconidia are echinulate (tuberculate) African Histoplasmosis Key features -Numerous large intracellular organisms in histiocytes and multinucleated giant cells -Evenly spaced distribution of organisms in giant cells Lobomycosis 12

13 2 year old Being Treated for Langerhans Cell Histiocytosis 13

14 Dermatobia hominis (Warble Fly) 14

15 15

16 Hansen s disease: Paucibacillary vs. Multibacillary 16

17 Rhinoscleroma Klebsiella rhinoscleromatis Plasma cells Russell bodies Mikulicz cells (resemble globi of leprosy) 17

18 Sandfly Leishmaniasis Bullous tinea 5 year old female Multiple subcutaneous nodules 18

19 Histoplasma capsulatum Macroconidia are echinulate (tuberculate) African Histoplasmosis Key features -Numerous large intracellular organisms in histiocytes and multinucleated giant cells -Evenly spaced distribution of organisms in giant cells Lobomycosis 19

20 Schistosomiasis Rhinosporidium 20

21 Blastomycosis Here Come Big Green Leafy Veggies PEH with neutrophilic microabsesses PEH with neutrophilic microabsesses Here - halogenoderma Come - chromomycosis Big - blastomycosis Green granuloma inguinale Leafy - leishmaniasis Veggies pemphigus vegetans Sporotrichosis Sporothrix schenckii Elongated conidophore with inflated tip bearing ovoid microconidia Rosettes Single celled conidia also form on both sides of the hyphae giving a sleeve shaped structure. 21

22 Sporothrix schenckii Disseminated disease in cats Found on the claws Transmitted to humans through cat scatches Tinea nigra Often excised as suspected melanoma Mildew organisms When it s humid enough, even the people mildew 22

23 Tungiasis Verrucous zoster = Immunosuppression (usually AIDS) Zoster HSV-1 23

24 Progressive disease misdiagnosed as impetigo Neonatal HSV Eczema Herpeticum HSV 24

25 Immunosuppression: Unusual manifestations Chronic ulcerative HSV HIV-positive male Punched out ulcers Culture mixed Gram negative organisms 25

26 Vascular necrosis Acanthamoeba Infection and Infestation Big fleas have little fleas upon their backs to bite em; and little fleas have smaller fleas, and so ad infinitum -Ogden Nash 26