Pathoma Flashcards
What is parakeratosis?
hyperkeratosis with retention of keratinocyte nuclei in stratum corneum
What is Auspitz sign?
pinprick bleeding when psoriasis scales are picked off. Due to elongated dermal papillae
What is a histological sawtooth appearance at the dermal-epidermal junction indicative of?
lichen planus
What does tombstone appearance refer to?
Pemphigus vulgaris. When basal layer cells remain attached to basement membrane via hemidesmosomes but desmosomes are destroyed so rest stratum spinosum separates. Leaves basal cells that look like tombstones
Describe pathology of Pemphigus Vulgaris
IgG antibody against desmoglein (type II hypersensitivity). Then acantholysis (separation) of stratum spinosum keratinocytes occurs and leave behind tombstome appearance of basal layer on basement membrane.
Which blisters are more likely to rupture: those of pemphigus vulgarus or bullous pemphigoid?
Pemphigus vulgaris. The bullae are thin walled and rupture easily leading to shallow erosions and dried crust
Which attachment proteins are targeted in Bullous pemphigoid?
hemidesmosomes
Which attachemtn proteins are targeted in pemphigus vulgaris?
desmoglein (desmosomes).
What is dermatitis herpetiformis?
deposition of IgA at the tips of dermal papillae. Pruritic vesicles and bullae grouped (herpetiform).
What other disease is dermatitis herpetiformis strongly assoicated with and how can it be prevented?
associated with celiac disease. Resolves with gluten-free diet.
What is erythema multiforme?
Hypersensitivity reaction characterized by targetoid rash and bullae. Most commonly with HSV infection or drug reactions. Can lead to Toxic epidermal necrolysis
What is seborrheic keratosis?
benign squamous proliferation. Presents as raised , discolored plaques. Coin-like, waxy stuckon appearance.
What is the Leser-Trelat sign? What does it indicate?
it is the sudden onset of multiple seborrheic keratoses. Suggests carcinoma of the GI tract
What is aconthosis nigricans? What is it associated with?
Epidermal hyperplasia and hyperpigmentation of axilla and or groin. Associated with insulin resistance
What is actinic keratosis?
precursor lesion of squamous cell carcinoma
What is keratoacanthoma?
well differentiated SCC that presents as a cub shaped tumor filled with deratin debris
What is vitiligo?
localized loss of skin pigmentation due to autoimmune destruction of melanocytes
What is albinism?
congenital lack of pigmentation due to enzyme defect (usually tyrosinase) which impairs melanin production
What is increased in freckles?
melanosomes. NOT melanocytes
What is impetigo?
superficial skin infection
What is cellulitis?
deeper (dermal and subcu) infection. Can profress to necrotizing fasciitis
What is scalded skin syndrome?
sloughing of skin with erythematous rash and fever. Significant skin loss. Caused by staph aureus. A and B toxins cause epidermolysis of stratum granulosum.
How is scalded skin syndrome differentiated from Toxic epidermal necrolysis?
the level of skin separation. TEN occurs at dermal-epidermal junction. SSS occurs at stratum granulosum.
What is a verruca?
wart.
What is molluscum contagiosum?
firm, pink, umbilicated papules due to poxvirus
