Exam 3: dermatopathology Flashcards
Palpable elevation filled with clear fluid
Vessicle or Bulla
what is the diff. b/t vesicle and bulla
vessicle is < 1cm
Bulla is > 1 cm
What are the 4 causes of vesicle or bulla formation
- Autoimmune dz
- viral inection
- Chemical irritants
- Burn
Vesicles and bullas are part of which pathologica process?
- Degeneration/ necrosis
2. Inflammation and repair
What are the 3 types of vesicle
- subcorneal
- suprabasal
- subepidermal
What forms the roof of a subcorneal vesicle
stratum corneum
what forms the roof of a suprabasal vesicle
epidermis
what forms the roof of a subepidermal vesicle
entire epidermis
palpable elevation filled with pus
Pustule
What pathologic process is a pustule?
Inflammation and repair
What causes pustule formation
leukocyte infiltrate
What is the common term for a pustule
acne
Dried exudate, serum, blood, and scale that is adhered to the skin surface
Crust
Crust is part of what pathologic processes
- Degeneration and necrosis
- Inflammation and repair
- Disorders of growth
What are the 3 causes of crust formation
- Disorders of keratinization
- pustular derm.
- secondary to ulcers
What is the common term for crust?
scab
Palpable, solid, elevated mass less than 1 cm
Papules
what are the 4 causes of papules
- infiltrate of inflam. cells
- infiltrate of neoplastic cells
- epidermal yperplasia
- deposit of mineral
What pathological processes does papules belong to
- inflammation and repair
- disorder of growth
- deposits and pigmentation
Papules greater than 1cm
Nodules
Coalesced papules
Plaques
Loss of epidermis with exposure of dermis
ulcer
Ulcers are secondary to waht 4 things?
- Epidermal necrosis
- Inflammation
- Infarction
- Neoplasia
Ulcers are part of which pathological processes
- Degeneration and necrosis
- Inflammation and repair
- Circ. disorders
- Disorder of growth
Accumulation of keritinized cells
Scale
What are the 2 causes of scale?
- Disorders of keratinization
2. Chronic derm
Scale is part of which pathological processes
- Inflam. and repair
2. Disorder of growth
Circ. rim of scale that occurs secondary to rupture of vesicle, pustule, or papule
Epidermal collarette
Thickening and hardening of the skin
Lichenification
What is the cause of lichenification
chronic irritation and inflam
Lichenification belongs to which pathological process
Inflammation and repair
What are the Do’s for collecting a skin biopsy
- biopsy before tx
- be gentile
- collect multiple samples
- include rusts
What are the Don’ts of collecting a skin biopsy
- surgically prep the site
- Grasp with forceps
- Biopsy the center of a lesion
- hold out on DDx or history
Degeneration/necrotic lesions become _____ overtime
inflam. and repair
What type of disorders typically lead to degeneration and necrosis
primary circ. disorders
What is the pathogenesis of photosensitization
- Uv light absorbed by photodynamic skin chemicals
- free radical dam.
- epidermal necrossis of lightly pigmented or sparsely haired skin
What are the two types of primary photosensitization
- Type 1 (exogenous)
2. Type 2 (Intrinsic)
What causes type 1 photosensitization
drugs or plants containing photosensitive chemicals
What causes type 2 photosensitization
Inherited deficiency of proporphyrinogen III cosynthetase which causes defect in heme synthesis and buildup of porphyrins
What are the two types of photosensitization
primary and secondary
What is the cause of secondary photosensitization
poor hepatic clearance of phylloerythrin
Toxins from secondary photosensitization cause what
biliary obstruction
Acute UV light exposure
Solar injury (sunburn)
Chronic UV light exposure leads to ____
solar/actinic keratosis
What is the Mdx of solar/actinic keratosis
Epidermal hyperplasia, dermal fibrosis and elastosis
Caused by exposure to excessive heat, hot liquids, heating pads, blow dryers, lighting.
thermal burns
What are the 3 degrees of thermal burns
- 1st degree
- second degree
- 3rd degree
what are the characteristics of 1st degree burn
- epidermis
- reddening necrotic epidermis
- complete healing
What are the characteristics of 2nd degree burns
- epidermis and dermis
- vesicle formation
- Some adnexa are preserved allowing epidermal regen. with some scaring
What are the characteristics of 3rd degree burn?
- full thickness
- sloughing of necrotic tisssue followed by granulation
- scar
- life threatening
Caused by body or wound seccretions, application of drugs, exposure to acids, alkalies, soaps, detergents or irritant plants
Chemical burns
Erythema mltiforme and toxic epidermal necrolysis patho. is thought to involve type __ hypersens.
4
Erythema multiform or Toxic epidermal necrolysis?
more severe, sheets of apoptotic/necrotic cells resembling a burn
TEN