Histopathology Flashcards
Difference between mucocutaneous pyoderma and DLE (aside from bacteria)
DLE has hydropic degeneration of basal cell layer AND interface band of inflammation
MCP has interface band of inflammation WITHOUT keratinocyte cytotoxicity!
Difference between interface cytotoxic dermatitis and panepidermal cytotoxic dermatitis
Interface: basal cell layer apoptosis only
Panepidermal: Multilayer apoptosis through epidermis
What category of diseases are cell-poor cytotoxic (interface) dermatitis
Chronic vasculopathies, Ischemic dermatopathy like dermatomyositis
2 causes for hydropic degeneration
Cell rich: CD8 T cells and NK cells mediate apoptotic cell death
Cell poor: hypoxia 2’ chronic vascular damage. Induces endoplasmic reticulum stress + autophagy
Where on the body are plasma cells present in cytotoxic interface dermatitis
Mucosal, mucocutaneous lesions
(otherwise, usually just lymphocytic +/- DCs, macrophages)
What are “sunburn cells”
Apoptotic keratinocytes 2’ UV damage. Usually in stratum spinosum. NO SATELLITOSIS w/T cells.
-CLE, photodermatoses
Which cytokine do Th1 CD4 T cells, CD8 T cells, ILC1, NK, NK-T cells produce
IFNg
Which cytokine is upregulated in dogs with CLE
IFNg
Which chemokine is upregulated in dogs with CLE
CXCL10 (made by T cells, keratinocytes)
Which diseases have confluences of apoptotic keratinocytes in the epidermis
SJS/TEN (but dermis is NORMAL)
Thermal burn (but dermis is ABNORMAL/ulcerated)
What causes thickening of the BMZ in DLE, MCLE, hyperkeratotic EM
Deposition of immunglobulins and immune complexes
What may cause dermal mucinosis in DLE
Keratinocytes upregulate versican 1 d/t IFNg stimulation
Cytotoxic panepidermal dermatitis with parakeratosis diseases [follicular infundibular epithelium severely affected + satellitosis] (4)
*Feline proliferative and necrotizing otitis externa
*Infiltrative mural folliculitis and dermatitis with apoptosis and parakeratosis (black labs)
*Hyperkeratotic EM
*Superficial necrolytic dermatitis
Acanthosis definition
Thickening of the stratum spinosum
Where are arrector pili muscles on the body
Dorsum
Animals with simple hair follicles
*Human
*Cattle
*Horse
*Pig
Animals with compound hair follicles
*Dog
*Cat
*Sheep
*Goat
Which animal has a thick connective tissue layer in the deep dermis
Horses
Where is skeletal muscle present in the skin?
Muzzle, forehead, eyelids, perianal region
Where is the stratum lucidum visible in dogs?
Pawpads
General causes for necrosis vs apoptosis
Apoptosis: immune-mediated
Necrosis: photosensitization, burn, TEN
Which protein and cells are implicated in TEN (full thickness epidermal necrosis)
Granulysin from CD8+ T cells and NK cells
Stain for mycobacteria
Acid fast, Fite
(short rods, filamentous)
Stain for Burkholderia
Warthin-Starry