Ch. 19 - Viral infections, helminths, and arthropods Flashcards
Verruca vulgaris
Exophytic papillomatous mass with compact eosinophilic hyperkeratosis. Koilocytes may be present.
Myrmecia
Deep palmoplantar wart with anthill-like appearance. Associated with HPV-1.
Verruca plana (flat wart)
Coarse basket-weave hyperkeratosis with hypergranulosis and “Bird’s eye” cells
Epidermodysplasia verruciformis (EDV)
Widespread flat warts with foamy blue cytoplasm
Condyloma acuminatum
Benign acanthoma on genital skin with vacuolated keratinocytes (true koilocytes are rare).
Bowenoid papulosis
Discrete sessile genital lesion with full-thickness atypia. Associated with HPV-16.
Heck’s disease
Focal oral hyperplasia. Hyperkeratosis with “round parakeratosis” and epithelial pallor. Associated with HPV-13 and -32.
Verrucous cyst (cystic papilloma)
Cyst with wart-like lining. Resembles myrmecia on feet.
Herpes simplex
Ballooning degeneration of keratinocytes with multinucleation and nuclear molding. Herpetic cytopathic effect. Mild leukocytoclastic vasculitis.
Herpes zoster (VZV)
Ballooning degeneration of keratinocytes with multinucleation and cytopathic effect. Dramatic leukocytoclastic vasculitis.
Chicken pox (VZV)
Ballooning degeneration of keratinocytes with multinucleation and cytopathic effect. Mild leukocytoclastic vasculitis.
Verrucous VZV infection
Hyperkeratosis and papillomatosis with follicular herpetic cytopathic effect. Usually in HIV+ patients.
Cytomegalovirus
Large endothelial cells with owl’s-eye nuclei.
Smallpox (variola)
Epidermal necrosis with reticular degeneration, eosinophilic inclusions (Guarnieri bodies), and nuclear inclusions
Monkey pox
Ballooning degeneration of basal keratinocytes with syncytia. Epidermal necrosis and spongiosis. Band-like and perivascular+periadnexal infiltrate.
Molluscum contagiosum
Cup-shaped lesion with scalloped border. Contains Henderson-Paterson bodies.
Orf and milker’s nodules
Epidermal necrosis with viral inclusion bodies. Long slender acanthosis?
Gianotti-Crosti syndrome
Papular acrolocated syndrome with papillary dermal edema, crust, and perivascular lymphoid infiltrate. HPV/HBV.
Hand, foot, and mouth syndrome
Oval vesicles with reticular and ballooning degeneration. Coxsackievirus.
Schistosomiasis
(types?)
Ova with stippled contents and a mixed, often granulomatous inflammatory response.
- *Haematobium**: Thin wall, vertical spine
- *Mansoni**: Thick wall, lateral spine
- *Japonicum**: Thick wall, no spine
Flatworms
Secretory tegument, rows of subtegumental cells. Calcareous bodies (waste), smooth muscle. No gut.
Elephantiasis
Filarial roundworms within lymphatic vessels (inflammatory response causes lymphedema)
Onchocercoma / microfilaria
Ball of male+female convoluted worms. Thin layer of striated muscle, corrugated cuticle. Large cephalic and caudal spaces.
Dirofilariasis
Thick muscular layer interrupted by lateral cords. Internal chitinous ridge.
Scabies
Mite, ova, or scybala in stratum cornea. Chitin scrolls/pigtails. Subepidermal bulla with eosinophils. Can mimic bullous pemphigoid or langerhans cell histiocytosis.
Insect bite
Dense wedge-shaped perivascular lymphoid infiltrate with eosinophils and variable vascular damage / atypical lymphocytes.
Insect sting
Highly variable. Often urticarial reaction followed by late stage fibrin/eosinophils/neutrophils.
Tick, tick bite
Wedge-shaped inflammation and necrosis. Look for pigmented mouthparts, blood-filled gut.
Myiasis
Fly larva with thick corrugated chitinous wall, pigmented setae, striated muscle, and gut.
Tungiasis
Organism with red hollow tubules, gut, striated muscle in acral skin.
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Verruca vulgaris
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Myrmecia
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Verruca plana
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Condyloma acuminatum
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Bowenoid papulosis
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Verrucous cyst
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Herpes simplex
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Herpes zoster (shingles)
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Varicella (chicken pox)
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Verrucous zoster
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Cytomegalovirus
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Smallpox (variola)
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Monkeypox
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Molluscum contagiosum
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Orf nodule
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Gianotti-Crosti syndrome
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Hand, foot, and mouth disease
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Cutaneous schistosomiasis
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Sparganum proliferum
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Elephantiasis
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Onchocercoma
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Onchocerca microfilaria
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Subcutaneous dirofilariasis
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Scabies mite
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Insect bite
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Tick bite
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Myiasis
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Tungiasis