Skin Flashcards
Flat lesion with well circumscribed change in skin color that is LESS than 5mm
Macule
Ex) freckle
A flat lesion with well circumscribed change in skin color that is GREATER than 5mm
Patch
Ex) large birthmark
Elevated solid skin lesion LESS than 5mm
Papule
mole, acne
Elevated solid skin lesion GREATER than 5mm
Plaque
psoriasis
Small fluid containing blister less than 5mm and greater than 5mm (2 answers)
Vesicle (lesser)
Bulla (greater)
A vesicle that contains pus
Pustule
Transient smooth papule or plaque
Wheal
Flaking off of stratum corneum
Scale
Dry exudate
Crust
What is hyperkeratosis?
Increased thickness of stratum corneum (outermost layer to the epidermis)
What is parakeratosis?
Hyperkeratosis with RETENTION OF NUCLEI in the stratum corneum
What is acantholysis?
Separation of epidermal cells
Ex) pemphigus vulgaris
What is acanthosis?
Epidermal hyperplasia –> increased spinosum
What is dermatitis?
Inflammation of the skin
Albinism has a __ melanocyte number with __ melanin production, due to a __ in ___ activity.
normal
decreased
tyrosinase
Albinism can be caused by a failure of ______
neural crest cell migration during development
What is hyperpigmentation that is associated with pregnancy or OC use?
Melasma (aka Chloasma)
Unlike albinism, this disorder has a decreased melanocyte number. It also involves irregular areas of complete depigmentation (like Dr. Makoske’s hands)
Vitiligo
Acne vulgaris can involve what types of lesions?
Comedones (whiteheads, blackheads)
Pustules (pimples)
Nodules (can lead to scarring)
What is the technical definition of acne vulgaris?
chronic inflammation of hair follicles and sebaceous glands
Sebaceous glands produce ___
Sebum
A hormone related increase in sebum can lead to formation of a ____
comedone
_____ infection often leads to inflammation, pustules, nodules, etc. related to acne
propionibacterium acnes
TX for acne?
Benzoyl peroxide
Vit A derivatives
What are melanocytes?
Cells responsible for skin pigmentation
Reside in basal layer of epidermis
Derived from neural crest
Synthesize melanin in melanosomes
(normal in albinism - decreased in vitiligo)
These are warts caused by HPV. They are soft, tan colored, cauliflower like papules. Morphology includes koilocytosis, hyperkeratosis, and epidermal hyperplasia. Condylome acuminatum on genitals.
Verrucae
What is a melanocytic nevus, and is it malignant or benign?
Common mole - benign, but melanoma can arise in congenital or atypical moles
What is urticaria?
Hives - pruritic wheals that form after mast cell degranulation
What is ephelis? There is a ___ melanocyte number and ___ melanin pigment.
normal melanocyte - increased melanin pigment
Atopic dermatitis typically shows up on the ____ surfaces?
Skin FLEXURES
“flex-cema” –> eczema on flexure surfaces
Atopic dermatitis is commonly associated with _____ because it is a ______ reaction.
Asthma, allergic rhinitis
Type I hypersensitivity
Pruritic eruption that usually starts in the face in infancy and spreads to antecubital fossa thereafter
eczema (atopic dermatitis)
Allergic contact dermatitis - everything you know about it - GO!
Type IV hypersensitivity
Follows exposure to allergen (nickel, poison ivy, neomycin, penicillin)
Lesions occur at site of contact
TX: remove offending agent
What are some major causes of allergic contact dermatitis?
poison ivy
penicillin
neomycin
nickel
Salmon colored plaques and papules and silvery scales
Psoriasis
What is Auspitz Sign?
IN PSORIASIS - Pinpoint bleeding spots from exposure of dermal papillae when scales are scraped off
Psoriasis involves acanthosis with _______
parakeratinocyte scaling
^nuclei still in stratum corneum
How does Psoriasis affect different layers of the epidermis?
increase stratum spinosum
decrease stratum granulosum
Nail pitting and arthritis are associated with ___
Psoriasis
Seborrheic keratosis as a general picture - what is it?
Looks like a “stuck on” lesion - flat, pigmented, greasy - on head, trunk, extremities
What type of cell proliferation is seborrheic keratosis?
squamous epithelial prolif with keratin-filled cysts
= horn cysts
An older patient presents with a small benign neoplasm on the trunk and extremities. She has a positive Leser-Trelat sign. What is this sign and what does the patient most likely have?
Leser-Trelat = sudden appearance of multiple seborrheic keratoses, indicating an underlying malignancy (GI?)
Seborrheic keratosis w underlying malignancy
List the major blistering skin disorders
Pemphigus Vulgaris Bullous Pemphigoid Dermatitis Herpetiformis Erythema Multiforme Stevens-Johnson Syndrome
Pemphigus Vulgaris
Potentially fatal autoimmune disorder with IgG antibody against DESMOGLEIN 3 = destruction of desmosomes
If desmosomes can’t hold together, then you get a separation between stratum basal and rest of epidermis = BLISTER
+ Nikolsky sign
Immunofluorescence shows FISHNET pattern
Acantholysis
Picture the image of the gross boobs in First Aid = multiple crusty, weeping lesions of broken blisters
Bullous Pemphigoid
Autoimmune IgG antibody against hemidesmosomes
Blister between epidermis and dermis (subepidermal)…eosinophils within tense blisters
Affects skin but spares oral mucosa
– Nikolsky sign
Bottom line: similar to pemphigus vulgaris, but blisters don’t really rupture and this is less severe (compare desmosome and hemidesmosome, and nikolsky)
Dermatitis Herpetiformis
Associated with Celiac Disease, so no surprise that this involves IgA deposition at the tips of dermal papillae
Appearance: pruritic papules, vesicles, and bullae (classically seen on elbows)
TX: …avoid gluten
Erythema Multiforme
Associated with: Infections Drugs Cancers Autoimmune Disease
Multiple types of lesions, especially TARGET LESIONS =
targets with multiple rings and dusky center showing epithelial disruption
What infections and drugs are associated with Erythema multiforme?
Mycoplasma penumoniae HSV Sulfa drugs (sulfonamides) B lactams Phenytoin
Stevens Johnson Syndrome is characterized by what?
Fever Bulla formation Necrosis Skin Sloughing High Mortality
What parts of body are involved with Stevens Johnson Syndrome and what do some of these lesions resemble?
2 Mucous membranes (think eye and lip)
Skin lesions
–> target appearance may mimic erythema multiforme
What is the more severe form of Stevens Johnson Syndrome?
Toxic Epidermal Necrolysis -
over 30% body surface involved.
Diffuse skin sloughing that resembles a large burn
May be due to adverse drug reaction
Epidermal hyperplasia causing symmetrical, hyperpigmented, velvety thickening of the skin = ______.
1) Where does it appear especially?
2) What other diseases is this associated with?
Acanthosis nigricans
Neck, axilla, groin
Hyperinsulinemia (diabetes, cushing, obesity) Visceral malignancy (gastric carcinoma)
Premalignant lesions caused by sun exposure. Appear as small, rough, erythematous brownish plaques. The risk of squamous cell carcinoma is proportional to ___________
Actinic keratosis
Risk of squamous cell carcinoma is proportional to degree of epithelial dysplasia
What is erythema nodosum?
Inflammatory lesions of subQ fat. Typically on anterior shins.
Which other diseases are associated with erythema nodosum?
Crohn disease Sarcoidosis Coccidioiodmycosis Histoplasmosis TB Strep Infxns Leprosy
What are the 6 Ps of Lichen Planus?
Pruritic
Purple
Polygonal Planar Papules
Plaques
What do you see at the dermal-epidermal junction in Lichen Planus?
Sawtooth infiltrate of lymphocytes
What virus is Lichen Planus associated with?
Hep C
What are Wickham Straie and in what disease do you see these?
Reticular white lines on the surface
Lichen PLanus
What disease classically begins with a singular, sometimes hidden, “herald patch” before spreading to more diffuse, multiple patches across the ribs of chest and back? TX?
Pityriasis Rosea
Herald patch –> Christmas tree distribution
Self resolves in 6-8 weeks
Which UV is dominant in tanning and photoaging? Sun burn?
UVA
UVB
B for Burn
UV irradiation causes DNA mutations, inducing apoptosis of ______.
Keratinocytes
Sunburn can lead to skin cancers and ___
impetigo
Very superficial, highly contagious skin infection that leads to crusting –> erythematous macules –> pustules. Caused by ____ and _____.
Impetigo
“honey crusted lesions”
Step pyogenes and staph aureus
What is bullous impetigo? Causative agent?
Fluid containing lesions of impetigo
staph aureus
What is the major difference between cellulitis and impetigo?
Impetigo is very superficial and cellulitis is a spreading infxn of the dermis and subQ tissues
Causative agents of cellulitis? Often starts due to what inciting event? May progress to …?
Strep pyogenes
Staph aureus
Break in skin from trauma or another infection
Necrotizing faciitis - medical emergency!
What does Necrotizing faciitis cause and what is the causative agent?
Crepitus, gassy methan and CO2 production - flesh eating bacteria - bullae and purple color to skin
staph aureus or anaerobic bacteria
Scalded Skin Syndrome
Staph aureus – A, B exotoxin destroys keratinocyte attachments in the STRATUM GRANULOSUM ONLY
Fever, sloughing of upper layers of epidermis, heals completely
Seen in newborns and children
EBV mediated white painless plaques on the tongue that CANNOT be scraped off
Hairy leukoplakia (common in HIV pts)
compare to scraped-off candidiasis
Molluscum contagiosum is seen with ____ virus
Pox
What is the most common skin cancer?
Basal cell carcinoma
Risks for Basal cell carcinoma?
Sunlight (UVB)
Albinism
Xeroderma pigmentosum
Basal cell carcinoma classically appears on ______.
the upper lip
Basal cell carcinoma’s pink pearly nodules commonly include:
1.
2.
3.
Telangiectasias
Rolled borders
Central crusting/ulceration
Is basal cell carcinoma invasive? How do you treat?
Invasive, but very rarely metastasizes
TX: excision
What are the risks factors predisposing to squamous cell carcinoma?
Albinism UVB xeroderma pigmentosum immuno suppression therapy arsenic chronic inflamm (burn scar?)
Which skin cancer typically appears on the bottom lip? Upper lip?
Squamous cell on bottom
Basal on top
Which skin cancer is associated with chronic draining sinuses?
Squamous cell
What is prognosis for squamous cell carcinoma? Is it invasive?
Excellent prognosis
Locally invasive, may spread to lymph nodes, rarely metastastizes
Actinic keratosis predisposes you to ___
squamous cell carcinoma
Keratocarcinoma
Variant of squamous cell carcinoma that grows rapidly (4-6 weeks) and may even regress spontaneously
Grows FAST, leaves FAST
Keratin pearls are seen in which type of skin cancer?
Squamous cell carcinoma
What is the MCC of death by skin cancer?
Melanoma
Risks for developing melanoma?
Albinism UVB Xeroderma pigmentosum Light skin color Dysplastic nevi syndrome
What are the two growth phases of melanoma?
- Radial growth - horizonal across epidermis and dermis
2. Vertical growth - down into the deep dermis
What are the four major types of melanoma?
Superficial spreading melanoma
Nodular Melanoma
Lentigo Maligna Melanoma
Acrolentiginous melanoma
Which is the MC melanoma variant?
Superficial spreading melanoma
has a dominant early horizontal/radial phase –> good prognosis
Which form of melanoma is unrelated to UVB? Where is it found?
Acrolentinginous melanoma
dark skinned individuals; palms, soles
Which melanoma has a poor prognosis and why?
Nodular melanoma
early vertical phase…burrows down in there…
Melanoma is often driven by activating mutation in _______?
BRAF kinase
Melanoma - depth of tumor correlates with ____?
risk of metastasis
If excision does not work well for pts with melanoma, what BRAF kinase inhibitor drug can be used?
vemurafenib
