Dermatopathology Flashcards
What is vitiligo?
Macules or patches of skinw with loss of pigment
areas affected: hands, wrists, perioral, and anogenital regions
Autoimmune? - don’t know what causes it.
Often found in type 1 diabetes, hashiomotos, and addisons disease
Freckles vs Lentigo?
Freckles are hyperpigmented lesions. They darken in sunlight
Lentigo is hyperpigmented lesion due to increase number of melanocytes along the basement membrane. They do not darken in sunlight
What happens in acute inflammatory process? What conditions does this encompass?
Acute inflammatory process lasts a few days to several weeks. Where micoscopic findings show neutrophils, edema, epidermal, vascular or subcutaneous injury occurs.
- This encompasses many conditions
- uticaria
- acute eczematous dermatitis
- erythema multiforme.
What is uriticaria? What type of immune reaction is it?
- Uriticaria is an acute inflammatory process. Also called hives
- It is an acute pruritic disease of short duration
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It is a type I immune reaction
- Local accumulation and degranulation of mast cells with histamine release and edema.
- Skin findings - pruritic nodule, edematous swelling (wheals) and plaques, formation of bullae
- Microscopic findings - perivascular edema
- Cause? - drugs, household exposures (new soaps) insect bites, foods
What is a morbilliform rash?
A “measles like” rash.
Causes - drug reactions, especially antibiotics such as sulfa, and “cillins”.
Starts on chest and spreads outward.
What is an exanthem? What is an enathem? What are they both caused by
Exanthem- Body-wide macular/papular rash
enanthem - lesions that occur in the mouth or in mucous mmebranes, - usually more vesicular
Both occur due to a virus
What is acute eczematous dermatitis? characteristics? What can it progress to?
Also known as eczema.
This is a rash that is characterized by erythema, edema, and veiscle formation
This can progress to oozing and crusting of papules and vesicles - watery and oozy.
Chronic raised plaques
What does microscopy of acute eczematous dermatitis show? What is the pathology and types?
Shows distinct eosinophilia and epidermal spongiosis
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Pathology - antigen take up by lengerhans cell and is presented to T cell, upon rexposure to T cell release of cytokines occurs
- types: allergic contact dermatitis, atopic dermatitis, irritant related dermatitis
What is Erythema multiforme? Most common cause?
This is a hypersensitivity reaction to infections. (HSV-90% of cases, mycoplasma), drugs (sulfonamides, penicillin, salicylates). Can also be seen in carcinomas and collagen vascular diseases
- Skin findings
- macules, papules, vesicles and bullae = multiforme, usually semetric involvement of the extremities
- It can form multiple types of morphology in one area
What are the different variants of erythema multiforme?
Steven Johnson Syndome
Toxic epidermal necrolysis
What is Steven Johnson syndrome? How do they present?
Steven-Johnson syndrome is a form of erythema-multiforme. Also known as EM major
- Patients present with
- fever
- Rash that involves lips and oral mucosa
- Risk of secondary infection leading to sepsis
- 10% of epidermal detachment
What is toxic epidermal necrolysis?
A form of erythema multiform that leads to diffuse sloughing and necrosis of cutaneous and mucosal epithelium. More than 30% epidermal detachment
Microscopy reveals – diffuse epidermal necrosis leading to blister formation, perivascular lymphocytes and dermal edema
What are chronic inflammatory skin conditions? Examples?
Conditions that last for several months to years
Chronic inflammation = thickening of the skin
Psorasis, seborrheic dermatitis
What is psoriasis? What sign is associated with it? Where are the common areas?
A skin condition that involves epidermal and dermis with epidermal hyperplasia and hyperkeratosis “thickening”
Skin findings - red plaques covered with silvery white scales. Removal of these scales causes petechial bleedings = Auspitz sign
Commonly affects elbows, knees, scalp, lumbosacral region, may involves nails-pitting of the nails
Microscopic elongated dermal papillae with thinning of overlying epidermis
Psoriatic arthritits related to ankylosing spondylitis - Positive for HLA B27
Treated with biologics
What is related to ankylosing spondylitis? What is the gene marker?
Psoriatic arthritis is related to ankylosing spondylitis. Positive for HLA B27
What is dermatitis herpetiformis? What is it related to? What antibody is it related to?
This is a skin disease that is characterized by pruritic vesicular dermatosis
- These are burning and itching lesions on the extensor surfaces, knees, elbows, back and buttocks
Related to gluten insensitivity - celiac sprue
Microscopy reveals cleft formation with dense neutrophilic infiltratoin and microabscess formation
Antiendomysial IgA antibody in the serum.
What is a seborrheic keratosis? Microscopic findings? Is it benign or malignant?
This is a dark brown papule with a stuck on appearence. Not related to seborrheic dematitis
Can be flat, or raised, sharpyl demarcated lesion with pink to brownish black pigmentation
Benign,
Microscopic findings- sheets of basal-like cells, hyperkeratosis, keratin filled cysts
Find in middle aged and older adults
What is an actinic keratosis? What does the microscopic view show?
A rough, sandpaper like lesion that can produce a horn
Microscopic - shows dysplasia of keritinocytes in the basal portion of the epidermis
Caused by UV exposure, precancerous lesion that can turn into squamous cell carcinoma.
What are the 4 types of pemphigus? Most common type?
Pemphigus Vulgaris, Pemphigus vegetans, Pemphigus foliaceous, pemphigus erythematosis
Most common type is pemphigus vulgaris. 80% of cases.
These are nikolsky sign positive.
What are bullous pemphigoid? How do you differentiate it from pemhigus
These are bullae that occur in elderly. They do not rupture easily and don’t have an erythematous base. Negative nikolsky
From an antibody against hemodesmosomes
Appear in a linear pattern at basement membrane on microscopy,
Oral mucosa involvement is less than with pemphigus
What is dysplastic nevus syndrome?
A familial melanoma syndrome
Autosomal dominant with high penetrance
Usually fair skinned with multiple irregular nevi with variegated color
HIGH RISK FOR MALIGNANT MELANOMA
increased risk of pancreatic cancer
if one family member has this, others are most likely to get it.
