Ch. 17 - Bacterial, spirochete, and protozoan infections Flashcards
Impetigo
(cause?)
Neutrophilic crust. Chains or clusters of cocci.
What conditions present with neutrophils in the stratum corneum?
PTICSS:
Psoriasis
Tinea
Impetigo
Candida
Seborrheic dermatitis
Syphilis
Bullous impetigo
Subcorneal bulla with acantholysis in granular layer.
Suppurative folliculitis
(cause?)
Supurative inflammation in or around a follicle. Crust in stratum corneum.
(could be bacterial, fungal, chemical…)
Botryomycosis
Large staphylococcal grains in tissue (resembles mycetoma) with abscesses and sinus tracts.
Pitted keratolysis
Dell or pit in stratum corneum with rods/cocci. Located in acral skin.
Erythrasma
Rods forming vertical filaments in startum corneum. Variable inflammation.
Ecthyma gangrenosum
(cause?)
Necrosis of deep dermal vessels surrounded by amphophilic bacilli. No inflammatory infiltrate!
(pseudomonas sepsis)
Rhinoscleroma
(cause?)
Sheets of plasma cells and russell bodies. Mikulicz cells (resembles globi of leprosy).
(Klebsiella rhinoscleromatis)
Chancroid
Ulcer with necrosis/fibrin at surface. Granulation tissue with plasma cells below.
Granuloma inguinale
Pseudoepitheliomatous hyperplasia with neutrophilic abscesses. Donovan bodies (organisms within histiocytes).
Lepromatous leprosy
Perivascular lymphohistiocytic infiltrate with ample amphophilic cytoplasm. May form sheets with Grenz zone. Globi (amphophilic collections of mycobacteria).
Tuberculoid leprosy
Epithelioid granulomas“running east-west”. Rare organisms.
Histoid leprosy
Fibrous nodules and globi. Usually the result of long-acting dapsone.
Recite three types of leprosy reactions.
1 (reversal/downgrading): Increased immune infiltrate.
2 (erythema nodosum leprosum): Leukocytoclastic vasculitis and onion-skin fibrosis with globi.
3 (Lucio’s phenomenon): Massive load of organisms, inflammation, and thrombosis in arterioles.
Tuberculosis
Early suppurative reaction becoming granulomatous with central caseous necrosis.
Syphilitic chancre
Typical-appearing ulcer (zone of necrosis, underlying granulation tissue & plasma cells). Spirochetes on silver/IF.
Secondary syphliis
Vacuolar interface dermatitis with slender psoriasiform acanthosis. Endothelial swelling obliterates vessel lumen. Perivascular lymphocytes and histiocytes.
Tertiary syphilis
Granulomas usually without visible organisms.
Erythema migrans
Highly variable perivascular infiltrate (may contain plasma cells and/or eosinophils). Spirochetes in silver-stained sections.
(very non-specific…)
Acrodermatitis chronica atrophicans
Dermal atrophy with sparse lymphohistiocytic band throughout dermis.
Leishmaniasis
Granulomatous dermatitis with intracellular organisms at periphery of vacuoles.
Acanthamoeba
Necrosis of deep vessels with organisms in vessel wall. Initially looks like large histiocytes.
Impetigo
