riosju10's version from 2016-05-30 22:09

Macroscopic terms

Question Answer Column 3
MaculeFlat lesion with well-circumscribed change in skin color < 1cmFreckle, labial macule
PatchMacule > 1cmLarge birthmark (congenital nevus)
PapuleElevated solid skin lesion < 1 cmMole (nevus), acne
PlaquePapule > 1 cmPsoriasis
VesicleSmall fluid-containing blister < 1 cmChickenpox, shingles
BullaLarge fluid-containing blister > 1 cmBullous pemphigoid
PustuleVesicle containing pusPustular psoriasis
WhealTransient smooth papule or plaqueHives (urticaria)
ScaleFlaking off of stratum corneumEczema, psoriasis, SCC
CrustDry exudateImpetigo

Microscopic terms

Question Answer
Hyperkeratosis↑ thickness of stratum corneum
ParakeratosisHyperkeratosis with retention of nuclei in stratum corneum
AcantholysisSeparation of epidermal cells
AcanthosisEpidermal hyperplasia (↑ spinosum)
DermatitisInflammation of the skin
SpongiosisEpidermal accumulation of edematous fluid in intercellular spaces

Skin disorders (Common, blistering)

Question Answer
Albinism↓ melanin production d/t ↓ tyrosinase activity or defective tyrosine transport (normal # of melanocytes)
Also caused by failure of neural crest cell migration during development
increase risk of cancer
Melasma (chloasma)Hyperpigmentation assoc w pregnancy or OCP use
"mask of pregnancy". Irregular blotchy patches
VitiligoIrregular areas of complete depigmentation
Caused by autoimmune destruction of melanocytes
increased risk of SCC, BCC
VerrucaeWarts - caused by HPV
Epidermal hyperplasia, hyperkeratosis, koilocytosis
Condyloma acuminatum on genitals (associated w HPV 6,11) with hyperkeratosis,Koilocytosis, hyper and para keratosis.
Melanocytic nevusCommon mole. Melanoma can arise from congenital or atypical moles
Intradermal nevi are papular
Junctional nevi are flat macules
Pruritic wheals that form after mast cell degranulation
superficial dermal edema, lymphatic channel dilation
Normal number of melanocytes, ↑ melanin pigment
Atopic dermatitis (eczema)Pruritic eruption, commonly on skin flexures, IgE mediated hypersensitivity
Assoc w other atopic diseases: asthma, allergic rhinitis
Starts on the face in infancy and appeas in antecubital fossae thereafter
Allergic contact dermatitisType 4 hypersensitivity rxn
(nickel, poison ivy, neomycin)
photodermatitis type: photosensitivity after Tetracyclin
PsoriasisPapules and plaques with silvery scaling, esp on knees and elbows
Acanthosis with parakeratotic scaling (nuclei still in stratum corneum)
↑ stratum spinosum, ↓ stratum granulosum, uniform elongation and thickening of rete ridge, thinning of epidermis over dermal papillae, munro microabcesses (in epidermis)
Auspitz sign - pinpoint bleeding spots from exposure to dermal papillae when scales are scraped off
Assoc w nail pitting and psoriatic arthritis, myopathy, entropathy
Seborrheic keratosisFLat, greasy, pigmented squamous epithelial proliferation w keratin-filled cysts (horn cysts) - looks "stuck on"
Lesions on head, trunk, extremities
Common benign neoplasm of older persons
Leser-Trelat signSudden appearance of multiple seborrheic keratoses, indicates an underlying malignancy (GI, lymphoid)
Pemphigus vulgarisPotentially fatal autoimmune skin disorder w IgG antibody against desmoglein 3 - desmosomes needed for cell adhesion
Immunofluorescence - antibodies around epidermal cells in reticular or netlike pattern
Acantholysis (keratinocytes in stratum spinosum connected by desmosomes)-->leaves behind a basal layer of keratinocytes;tombstone-like - intraepidermal bullae causing flaccid blister involving the skin and oral mucosa
Positive Nikolsky's sign - separation of epidermis upon manual stroking of skin
Bullous pemphigoidHypersensitivity type II, Autoimmune disorder with IgG antibody against hemidesmosomes (epidermal BM)--->blisters: subepidermal
Linear immunofluorescence at epidermal-dermal junction
Eosinophils within tense blisters
Spares oral mucosa
Negative Nikolsky's sign - skin doesn't fall off when you stroke it
Dermatitis herpetiformisPruritic papules, vesicles, and bullae - usually on extensor surface, --->blisters: subepidermal
IgA deposits/neutrophils at tips of dermal papillae
Assoc w Celiac disease
Erythema multiformeInfections - Mycoplasma pneumoniae, HSV
Drugs - sulfa, β-lactams, phenytoin, penicillin, barbiturates
Autoimmune diseases
Multiple types of lesions: macules, papules, vesicles, target lesions
Stevens-Johnson syndromeFever, bulla formation and necrosis, sloughing of skin, and a high mortality rate
2 mucus membranes are involved (eyes, mouth, etc) - lesions may appear like targets
Assoc w adverse drug rxn
Toxic epidermal necrolysisA more severe form of Stevens-Johnson syndrome with > 30% of the body surface area involved

Skin disorders (Misc. and infectious)

Question Answer
Acanthosis nigricansEpidermal hyperplasia causing symmetrical, hyperpigmented, velvety thickening of skin on neck or armpits
Assoc w hyperinsulinemia (diabetes, obesity, Cushing's syndrome)
visceral malignancy (gastric adenocarcinoma)
polycystic ovary disease
Actinic keratosisPremalignant lesions caused by sun exposure
Small, rough, erythematous or brownish papules or plaques
Risk of squamous cell carcinoma is proportional to degree of epithelial dysplasia
Erythema nodosumInflammatory lesions of subcutaneous fat, usually on anterior shins, raised, erythematous, painful nodules
Assoc w
streptococcal infxns
Crohn's disease
Lichen PlanusPruritic
Polygonal Planar Papules and Plaques
Sawtooth infiltrate of lymphocytes at dermal-epidermal jct
Assoc w Hep C
Pityriasis rosea"Herald patch" first (2-10 cm rash on chest) followed days later by "Christmas tree" distribution
Multiple plaques with collarette scale
Self-resolving in 6-8 weeks
SunburnUV irradiation → DNA mutations → apoptosis of keratinocytes
UVA - tanning and photoaging
UVB - sunburn
Can lead to impetigo and skin cancers (Basal cell, squamous cell, and melanoma)
ImpetigoVery superficial skin infections
Staph aur or Strep pyogenes
Highly contagious
Honey-colored crusting
Bullous impetigohas bullae and is usually caused by Staph a
CellulitisAcute, painful, spreading infxn of dermis and subQ tissues
Usuall Strep pyogenes or Staph aur
Starts with a break in skin from trauma or other infxn
Necrotizing fasciitisDeeper tissue injury - anaerobic bacteria or Strep pyogenes
Crepitus from methane and CO2 production
"Flesh-eating bacteria"
Bullae and purple color
Staphylococcal scalded skin syndrome (SSSS)Exotoxin destroys keratinocyte attachments in stratum granulosum only (vs toxic epidermal necrolysis which destroys epidermal-dermal jct)
Fever, generalized erythematous rash w sloughing of upper layers of epidermis - heals completely
Newborns and children
Hairy leukoplakiaWhite, painless plaques on tongue - cannot be scraped off
EBV mediated
Occurs in HIV positive pts

Image quiz

Question Answer
Melasma (chloasma)
Melanocytic nevus
Atopic dermatitis (eczema)
Allergic contact dermatitis
Seborrheic Keratosis
Pemphigus vulgaris
Bullous pemphigoid
Dermatitis herpetiformis
Erythema multiforme
Stevens-Johnson syndrome
Acanthosis nigricans
Actinic keratosis
Erythema nodosum
Lichen Planus
Pityriasis rosea
Necrotizing fasciitis
Staphylococcal scalded skin syndrome (SSSS)
Hairy leukoplakia

Skin cancer

Question Answer
What is the most common skin cancer?Basal cell carcinoma
Locally invasive but never metastasizes, grows slowlyBasal cell carcinoma
Pink, pearly nodules w telangiectasia, rolled borders and central crusting or ulceration (rodent ulcers)Basal cell carcinoma
Commonly with telangiectasiasBasal cell carcinoma
nonhealing ulcers with infiltrating growthBasal cell carcinoma
scaling plaqueBasal cell carcinoma
Palisading nuclei, nests of basaloid cells in dermisBasal cell carcinoma
Second most common skin cancersquamous cell carcinoma
Immunosuppressionsquamous cell carcinoma
Arsenic exposuresquamous cell carcinoma
Commonly on face, lower lip, ears, and handssquamous cell carcinoma
Maybe LNs, but rare metastasissquamous cell carcinoma
Chronic draining sinusessquamous cell carcinoma
Ulcerative red lesions with scaling, histo: keratin pearlssquamous cell carcinoma
Actinic keratosis is a precursor, Bowen diseasesquamous cell carcinoma
Keratoacanthomavariant of squamous cell carcinoma, well differentiated, dome-shaped nodule w keratin-filled crater.
grows rapidly (4-6 weeks) and may regress spontaneously over months
Significant risk of metastasisMelanoma
S-100 tumor markerMelanoma
Fair-skinned persons are at ↑ riskMelanoma
Depth of tumor correlates with risk of metastasisMelanoma
ABCDEs of melanomaAsymmetry, Border irregularity, Color variation, Diameter > 6mm, Evolution over time
Activating mutation in BRAF kinaseMelanoma
vemurafenibmetastatic/ unresectable melanoma in pts with BRAF V600E mutation