#DermTerms Flashcards
Palpable elevation filled with clear fluid
Vesicle <1cm
Bulla >1cm
What are causes of vesicle/bulla formation
Auto-immune dermatoses
Viral infection
Chemical irritants
Burns
(Degeneration/necrosis or inflammation/repair)
What three changes can lead to formation of a vesicle/bulla?
Intercellular edema (spongiosis) Intracellular edema (hydropic degeneration Disruption of intracellular junctions (acantholysis
Spongiosis means
Intercellular edema
Acantholysis means?
Disruption of tight junctions ->then we fill up with fluid
What is a palpable elevation filled with pus?
Pustule
What usually causes pustules?
Leukocyte infiltrate (inflammation and repair)
Dried exudate, serum, blood, or scale is called ????
Crust
What causes crust formation?
Disorders of keratiniztion
Severe pustular dermatitis
Secondary to ulcer
What is a palpable, solid, elevated mass <1cm
Papule
What re the causes of papules?
Infiltrate of inflammatory cells
Infiltrate of neoplastic cells
Epidermal hyperplasia
Deposit of mineral
A papule that is >1cm is called?
Nodule
What is a plaque
Coalesced papules
Loss of epidermis with exposure of dermis is called?
Ulcer
Ulcers are caused by…..
Secondary to
- epidermal necrosis
- inflmmation
- infarction
- neoplasia
___________ is an accumulation of losse keratinized cells
Scale
Cause of scale
Disorders of keratinizaiton
Chronic dermatitis
__________ is a circular rim of scale that occurs secondary to rupture of a vesicle, pustule, or papule
Epidermal collarette
Thickening and hardening of the skin, usually see criss cross pattern
Lichenificiation
What are the causes of lichenification?
Chronic irritation/ inflammation
When should biopsy be collected?
Early, before treatment
What should you not do when collecting a skin biopsy?
Surgically prep the site
Grasp with forceps
Biopsy the center of a lesion
Hold out on history
You see the following skin lesions Edema Erythema Alopecia Crusting Ulceration
What is the likely pathological processes?
Degeneration and necrosis
Inflammatory
What is the pathogenesis of photosensitization?
UV light absorbed by photodynamic chemicals in skin -> free radical damage -> epidermal necrosis of lightly pigmented or sparsely haired skin
What are the types of primary photosensitization?
Exogenous (type 1)
-drugs or plants containing photosensitive chemicals
Intrinsic (type 2)
-inherited deficiency of proprohyrinogen III cosynthetase -> defect in heme synthesis -> build up of prophyrins
Secondary photosensitization is due to?
Type III -> hematogenous photosensitization
Poor hepatic clearance of phylloerythrin (producer of rumenal chlorophyll transformation)
Toxins causing biliary obstruction
pale oral mucous membranes and udders that are slightly reddened are characteristics of?
Erythropoietin porphyria
Primary photosensitization -> deficiency of proporphyrinogen III -> deficient heme synthesis s-> porphyrins build up
A Holstein cow presents with large patches of erythema and edema. There are also vesicles, stabbing, and ulceration. These lesions are localized mainly on the back in the light coloured hair. What is the most likely diagnosis?
Photosensitization
What is the pathogenesis of acute UV light exposure
Sunburn
Radiation -> endothelial damage and cytokine production -> erythema -> vesicles -> soughing of necrotic skin
Chronic UV light exposure can lead to __________
Solar/actinic keratosis
T/F: animals with actinic keratosis are more at risk for neoplasia due to direct DNA injury and subsequent mutations
T
Nonpigmented and sparsely haired skin is erythemaous, has comedones, crust, is thickened.
What am i??
Solar/ actinic keratosis
What is a comedone?
Black head
Pore that is distended and filled with keratin
The rupture of a comedone is called?
Furunculosis
Thermal burn that is on the epidermis, reddened/darkened necrotic epidermis, will completely heal
1st degree
Thermal burn that involves the epidermis and dermis and has vesicle formation. Some adnexa are preserved allowing regeneration and some scaring
2nd degree
Thermal burn that involves epidermis, dermis, and subcutis. Necrotic tissue sloughs off, followed by granulation tissue and leaves a scar
3rd degree
_________ burns are caused by body or wound secretions, application of drugs, exposure to acids, soaps, detergents, or irritant plants
Chemical
T/F: chemical burns are usually mild irritants and must penetrate hair and protective epidermal layers to have effect
True
Erythema multiforme and toxic epidermal necrolysis is due to what
Type IV hypersensitivity towards antigens of the surface keratinocytes inducing apoptosis
What is the difference between erythema multifome and toxic epidermal necrolysis
EM
- mild
- single cell apoptosis +/- lymphocyte satellitosis
TEN
- severe
- sheets of apoptotic/necrotic cells resembling a burn
Wide spread coalescing erythematous macules -> vesicles and ulcers
Erythema multifome and toxic epidermal necrolysis
When you see a burn, your pathological process is _______________
Degeneration/necrosis
