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52 Cards in this Set
- Front
- Back
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Components of the skin |
Dermis, epidermis, subcutis, hair follicle, salivary glands, sebaceous glands |
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Components of the epidermis |
Superficial to deep: Stratum corneum, stratum granulosum, stratum spinosum, stratum basale, basementmembrane |
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Erythema |
Gross lesion of skin; Reddening of the skin
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Macule |
Gross lesion of skin; circumscribed, flat discoloration of skin UP to 1 cm Causes: hemorrhage, hyperemia or increased/decreased pigmentation Example: freckle |
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PuraPura |
Macule caused by hemorrhage |
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Papule |
Gross lesion of skin: Solid circumscribed elevation of skin UP to 1 cm ( height) |
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Plaques |
Larger, usually flat topped elevations formed by COALESCING papules red/blue= acute yellow/brown= chronic |
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Nodule |
Gross lesion of skin: Circumscribed elevation usually GREATER than 1 cm in height, solid and rooted in dermis or subcutis May be cystic inflammatory or neoplastic |
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Wheals |
(urticaria, hives) Gross lesion of skin: white to pink, mesa-like elevation produced by EDEMA in dermis May coalesce to form plaques and are TRANSIENT Example: acute allergic reaction |
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Vesicle |
(Blisters) (similar larger lesion: Bleb/bullae) Gross lesion of skin: Small elevation of epidermis caused by a pocket filled with CLEAR SERUM ( in or immediately beneath epidermis) Causes: viruses, chemicals, burns and autoimmune |
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Pustule |
Gross lesion of skin: Superficial Abscess. Vesicle that contains neutrophils AND serum. Vesicles can become pustules (pustule= vesicle+bacteria) |
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Scales |
Gross lesion of skin: flakes of imperfectly cornified superficial epidermis Seen focally in chronic dermatitis |
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Crusts |
Gross lesion of skin: scabs, made of dried accumulations of serum, blood, pus, epithelial and bacterial debris |
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Ulcer |
Gross lesion of skin: loss of EPIDERMIS to and into the dermis |
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Erosion |
loss of part of epidermis ( not straight through to dermis; hard to visualize grossly ) |
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Change in pigmentation |
Related to melanin in epidermis (hypo/hyper pigmentation) |
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Lichenification |
Gross lesion of skin: irregular SKIN THICKENING (acanthosis, hyperkeratosis) and hyperpigmentation. Cause: hyperpigmentation |
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Verruca |
Gross lesion of skin: an elevated rough, WARTY lesion |
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Scar |
Gross lesion of skin: fibrous tissue replacing normal tissue injured by disease or injury. in skin often alopecic and DEpigmented |
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AcanTHOSIS |
Microscopic lesion of skin: thickening due to HYPERPLASIA of epidermis ( stratum spinosum) Response to chronic irritation |
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Pustule |
Microscopic lesion of skin: superficial abscess. Vesicle that contains neutrophils AND serum. Same descriptive gross lesion term |
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Hyperkeratosis |
Microscopic lesion of skin: Exccessive thickness or hyperplasia of STRATUM CORNEUM. Seen in mild, chronic irritation Focal: Callus or Generalized |
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Orthokeratosis |
Hyperkeratosis of "normal appearing" keratin layers ( no nuclei) |
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Parakeratosis |
Retention of cell nuclei with in keratin |
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AcanthoLYSIS |
Microscopic lesion of skin: Loss of cohesion between epidermal cells due to DEGENERATION of desmosomes Can see acantholytic cells floating |
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Spongiosis |
Microscopic lesion of skin: intracellular edema in the epidermis. Leads to vesicle formation |
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Ballooning degeneration |
Intracellular edema or hydropic degeneration of epidermal cells. Can coalesce and form vesicle Often seen in pox disease |
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Types of cutaneous inflammation |
Perivascular Vascular Interface Hyperplastic Luminal Folliculitis Furunculosis Epidermal Pustule Nodular/diffuse |
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Acute Dermatitis GROSS |
erythema Vesicle Pustules Wheals Exudation= serous, fibrinous,purulent Crusts Ulcers |
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Acute Dermatitis MICRO |
Spongiosis, Ballooning degeneration Vesicles, Pustles, Exocytosis (neutrophils) Dermal edema, Vascular dilations Necrosis, Fibrin, Thrombosis, acute inflammatory infiltrates-fibrin,neutrophils |
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Resolution of Acute Dermatitis |
Complete resolution Scarring Progress to chronic? |
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Chronic Dermatitis GROSS |
Scaling Crusts Epidermal thickening-hyperplasia, lichenification, pigmentary changes, fibrosis |
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Chronic Dermatitis MICRO |
Acanthosis, hyperkeratosis, fibrosis, chronic (mononuclear) cellular infiltrates-macrophages, plasma cells, lymphocytes |
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Resolution of Chronic Dermatitis |
Persistent chronic inflammation lichenification Fibrosis and scarring |
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Causes of Dermatitis |
Bacteria Viral Fungal Parasitic Endogenous |
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Bacteria |
superficial pyodermas deep pyodermas bacterial granulomatous demrmatitis systemic or toxic reactions bacterial digital infections of horses/ruminants |
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Examples of Bacterial cause |
deep pyoderma--> staph in hair follicle Dermatophilus congolensis ( rain rot, laminated crusts and hyperkeratosis) Papilomatous digital derm |
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Papillomatous digital dermatitis |
painful disease of feet in cattle multi bacterial involved (treponema) interdigital space plantar surface hind foot caused by prolonged period in wet dirty environment severe epidermal hyperplasia ( stage wart like growths!) |
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Viral |
Canine distemper virus herpes virus papillomavirus swine pox |
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Mechanism of injury in POX |
1) Balloonning degeneration 2) reticular degeneration and inclusion bodies 3) Macule formed 4) Papule formed 5) Vesicle formed 6) Pustule/papule formed 7) Hyperplasia and old pustule 8) Hyperplasia and crust |
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Fungal- cutaneous |
hair, stratum corneum, claws=
Dermatophytes, Candida, Malassezia |
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Fungal- Subcutaneous |
Pythiosis |
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Fungal- Systemic |
Blastomycosis, cryptococcosis |
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Parasitic |
Athropods helminths filaria |
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Arthropods |
Fleas Mites= demodex and sarcoptes |
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Helminths |
Habronema Hook worm |
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Filaria |
Stephanofilaria |
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inflammation of derm WITHOUT pathogens |
Photodynamic dermatitis |
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Photodynamic dermatitis |
Photosensitizers
porphyria Hepatogenous |
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Photosensitizers |
Primary cause of photodynamic derm they are EXOGENOUS substances such as plants and drugs |
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Porphyria |
Metabolic disorder of porphyrin metabolism Endogenous cause of photodynamic derm. |
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Hepatogenous |
Feed contians chlorophyll--> turned into phylloerythrin in the RUMEN--> liver dysfunction= enters circulation --> skin = photoactivation= FREE RADICALS!= photodynamic dermatitis |
