First Pass Miss Flashcards
Give some UVA vs UVB?
UVA - Avobenzone, mexorl, parsol
UVB (more important) - Paba, cinnamates, salicylates
Treat sunburn with moisturizers and NSAIDs, not Lidocaine cuz they can develop a hypersensitivity
What is scale vs crust?
Scale - Shedding / flaking of the stratum corneum, usually due to thickening / increased cell turnover (i.e. psoriasis has scaling of plaques)
Crust - dried exudate of some kind (i.e. impetigo)
Define lichenification.
Thickening of skin with accentuation of skin lines
What is a telangiectasia and when do they commonly occur?
Dilated superficial blood vessels, often in chronic sun damage
What are granulomatous skin conditions and some examples?
Papules and plaques with no scaling, deep dermal inflammation
i.e. Granuloma annulare, sarcoid, necrobiosis lipoidicum (NLD), mycobacteria, deep fungal
What is the typical progression of an acquired nevus on the microscopic level?
- Junctional nevus - melanocyte nests grow at the dermal-epidermal JUNCTION, childhood
- Compound - Nevus cells grow at DEJ and inward into the dermis
- Intradermal nevus - nevus nests lose their junctional component and grow directly into the dermis, adulthood
flat brown -> raised brown -> raised fleshy.
What are important risk factors for melanoma?
Fair skin type (blondes and gingers), especially red hair (melanocortin receptor polymorphism)
Xeroderma pigmentosum
Ultraviolent light exposure (like phototherapy -> immunosuppression, as well as formation of ROS / thymidine dimers)
H/o dysplastic nevi (Clark’s nevi) ormelanoma
What are the four core types of melanoma? Which is most common?
- Superficial spreading - most common
- Nodular
- > early vertical growth, poor prognosis - Lentigo maligna
- > sun-exposed face of elderly - Acral lentiginous
- > most common melanoma of blacks, not related to UV exposure
What is Hutchinson’s sign?
Black or brown pigmentation of the normal nailplate in conjunction with pigmentation of the proximal nail fold
-> a sign of subungal acral lentiginous melanoma
What activating mutation is a common driver of melanoma and what should be used to treat it?
BRAF kinase
Used vemurafenib, a BRAF kinase inhibitor
“ve-mural” of melanoma
Mek inhibitors as well
What condition is viewed as a precursor condition to squamous cell carcinoma, and what patient population is most susceptible?
Actinic Keratosis (AK)
Transplant patients are most susceptible to progression to squamous cell carcinoma, and the lesion is also more common in them
-> Intraepidermal, partial thickness atypia of epidermis
What is the second most common skin cancer and what will the lesion generally look like?
Squamous cell carcinoma
Looks like dull red, firm nodules with adherent yellow-white SCALE. May ulcerate and have necrotic center + bleeding
How do basal cell carcinomas appear grossly and what are the major risk factors?
Generally appears as pink or pearly-white nodules with overlying telangiectasias. Can bleed, become erosive, and ulcerate in the center. May develop a raised, rolled border.
Risk factor: cumulative UV exposure
What are risk factors for squamous cell carcinoma?
- Ultraviolet light exposure
- Immunosuppression (i.e. transplants)
- Chronic inflammation, i.e. due to chronically draining sinus tracts (i.e. from osteomyelitis) or scars from burns
- Arsenic exposure -> causes hyperkeratosis
What SqCC’s are at high risk of metastasis?
Large tumors which are poorly differentiated, especially in immunosuppressed, on chronic wounds, or on ears / lips.
Metastatic tumors will also often show perineural invasion
What is a Keratoacanthoma? What does it look like / what is the prognosis?
Invasive squamous cell carcinoma variant with cup-like shape and keratotic debris in the middle (central keratotic core)
Prognosis - Rapidly progresses for 4-6 weeks, then often spontaneously regresses over months
What is a verrucous carcinoma and where do they appear?
SqCC variant which presents as a warty plaque on plantar feet or distal fingers, often HPV-related
What skin condition can mycosis fungoides cause once it has progresses to Sezary syndrome?
Erythroderma and generalized scaling (exfoliative dermatitis) -> skin becomes very red, palms and soles are thickened, with general pruritis / skin redness
-> patients need to be treated aggressively, possibly with extracorporeal photopheresis (like photodynamic therapy but directed towards T cells in blood)
What are the four clinical variants of Kaposi sarcoma?
Classic - Older individuals of Mediterranean or Eastern European background
-> indolent, affecting lower extremities especially
Endemic - Tropical Africa -> aggressive, affecting lymph nodes first
Immunosuppressed - will improve upon cessation of immunosuppressive therapy
AIDS-associated / epidemic - multifocal or widespread disease
Bosch groups these last two together
What is the spread pattern of AIDS-associated (epidemic) Kaposi’s sarcoma?
Predilection for face (nose, eyelids, ears), and can even involve oral mucosa. Systemic involvement of GI tract / visceral organs makes it problematic
-> especially stomach / duodenum
What is solar lentigo also called and what causes it? Where can they be found?
Lentigo senilis, or “liver spots”
- > associated with age and exposure to UV radiation
- > found photodistributed to hands, face, shoulders, arms, and forehead
vs lentigo simplex -> in children, not sunrelated
Who gets sebaceous hyperplasia and how will it appear?
Middle-aged to elderly adults
Appears as fleshy to slightly yellow papules, sometimes with central punctum (sebaceous glands associated with hair follicles)
How does a dermatofibroma progress, and what does it look like under the microscope?
Lesions can be solitary or multiple, and they tend to persist indefinitely while remaining stable in size / appearance
Histology - looks like a scar (localized area of fibroblasts in the skin)
Typically on legs of adults, must be differentiated from melanoma
What does a keloid look like under the microscope and how is it treated?
Looks like disorganized fibers of collagen and whorls of fibroblasts
Treated with repeat injections of steroids into the lesion to cause atrophy
Surgery is CONTRAINDICATED and will worsen the condition
What is an epidermoid cyst, what is it made of, and where is it found?
Mobile, firm, relatively superficial subcutaneous nodule with a punctum which appears as an open comedo (blackhead)
Made of keratin, much like milia, but larger.
Can be found anywhere on the skin
-> may rupture and cause acute inflammation
What do you call a firm nodule limited to the scalp which is benign and can be removed surgically? What is it made of?
Trichilemmal cyst
Made of layers of cornified lamellated keratin, can be removed when not inflamed
What is a cherry hemangioma and who gets them? Do they blanch?
Benign capillary hemangioma of the elderly (Phyllis’s ELDERLY cherries story)
- > Round, smooth, dome-shaped nodule made of dilated capillaries and postcapillary venules
- > does NOT blanch
What is the natural course of pyogenic granuloma? Where is it typically found?
Occurs due to chronic irritation or hormonal influences (it is associated with pregnancy)
Grows rapidly, then spontaneously regresses in a few months
- > commonly found on gums / in mouth, but can be on head, neck, trunk, or limbs
- > excision is curative
How does acute ICD appear? Common locations?
Usually well demarcated (borders of where irritant touched) erythematous and scaly patches and plaques
Severe disease can develop vesicles and bullae
Common locations: Hands, forearms, eyelids, face
What is the morphology of the rash in atopic dermatitis? Include chronic changes.
Red, crusted, scaly, pruritic plaques with vesicles and edema
If chronic: Lichenification and hyperpigmentation
What is one big way to tell eczema apart from candidiasis or Letterer-Siwe (Langerhans cell histiocytosis)?
In eczema, the diaper area is spared.
It is heavily involved in these two conditions.
How does eczema look in skin of dark-skinned people?
Often appears brown or purple, with erythema appreciated at periphery
Can leave post-inflammatory hyperpigmentation
What are some prescription options for the treatment of eczema? Side effects?
- Topical steroids (ointments most potent) -> cutaneous atrophy
- Topical calcineurin inhibitors - pimecrolimus / tacrolimus -> black box warning of lymphoma
- Systemic steroids -> have high rate of relapse
- Phototherapy + systemic immunosuppressives -> UVA, narrow band UVB, MTX, AZA to calm immune response
What are serious infections which can arise in the setting of atopic dermatitis and how are they avoided / treated?
Staphylococcal - avoid with bleach paths, treat with antibiotics
VZV, HSV - Eczema herpeticum, treat with antivirals, but can be a dermatologic emergency requiring IV rehydration and antivirals
What disease is characterized by coin-shaped, scaly red/brown pruritis plaques with NO central clearing? What symptoms will the patient show?
Nummular dermatitis
Patient shows severe pruritis -> scratching often becomes habitual
- > middle aged / elderly, worse in winter, use high dose topical steroids
- > more eczematous and borders less well defined than psoriasis
What does Lichen Simplex Chronicus look like? Where is it commonly found?
Lichenified, often hyper-pigmented plaques
Trunk, extremities, and scrotum is very common
Due to chronic itching as in atopic dermatitis, ESRD, liver disease
Treat with antidepressants / antihistamines if needed, try to show patient habitual nature of their scratching
What are classical findings on skin biopsy of psoriasis?
- Acanthosis - epidermal hyperplasia
- Parakeratosis - hyperkeratosis with retention of keratinocyte nuclei in stratum corneum
- Monro microabscesses Neutrophils in stratum corneum
- Thinning of epidermis above elongated dermal papillae -> pinpoint bleed = Auspitz sign
NOTE: psoriasis happens on extensor surfaces like elbows / knees, + umbilicus
What is the Koebner phenomenon? Does this occur in psorasis?
When skin lesions appear at the site of physical trauma, i.e. scratching, sunburn, surgery
Yes, this occurs in psoriasis very prominently