Dermatology Flashcards
1
Q
basal layer/stratum basale
A
bottom-most layer of the epidermis, attached to the basement membrane; houses stem cells that maintain the epidermis; when a stem cell divides, it creates both a daughter stem cell and a transient amplifying cell
2
Q
spinous layer/stratum spinosum
A
second-deepest layer of the epidermis, located between the basal layer and the granular layer; contains the majority of the skin’s keratinocytes (i.e., thickest layer), which are held together by desmosomes, gap junctions, adherens junctions, and tight junctions
3
Q
granular layer/stratum granulosum
A
second-most-superficial layer of the epidermis, located between the spinous layer and the cornified layer; keratinocytes in this layer are flattened, begin to lose their nuclei, and contain keratinohyaline granules and lamellar granules
4
Q
transluscent layer/stratum lucidum
A
additional layer of the epidermis located between the cornfield layer and the granular layer; present only on the palms and soles
5
Q
cornified layer/stratum corneum
A
most-superficial layer of the epidermis; contains corneocytes held together by a cornified envelope, made up of proteins and lipids released by keratohyalin and lamellar granules of the granular layer; thickness of this layer varies depending on the body area
6
Q
keratinocyte
A
keratinized cells of the epidermis of the skin; contain keratin, an intermediate filament, made up of heterodimers of alpha-helical type I (acidic) and type II (basic) keratin monomers; derived from stem cells in the basal layer of the epidermis, undergo cornification as they differentiate and mature (takes appx. 28 days)
7
Q
corneocyte
A
anucleate keratinocytes held together by the cornified envelope found in the cornified layer of the epidermis
8
Q
desmosome
A
adhesive protein that connects to keratin intermediate filaments intracellularly and to neighboring cells extracellularly; holds neighboring cells together in the epidermis
9
Q
keratohyalin granules
A
granules present in keratinocytes of the granular layer of the epidermis; contain proteins important for formation of the cornified envelope, including profilaggrin
10
Q
lamellar granules
A
granules present in keratinocytes of the granular layer of the epidermis; contain ceramides and cholesterol that contribute to the lipid barrier of the cornified layer and hydrolytic enzymes that promote desquamation of the cornified layer
11
Q
filaggrin
A
protein found in keratohyalin granules of the keratinocytes in the granular layer of the epidermis; contributes to the cornified envelope of the cornified layer
12
Q
ceramide
A
lipid found in lamellar granules of the keratinocytes in the granular layer of the epidermis; contributes to the cornified envelope of the cornified layer
13
Q
desmoglein
A
protein that makes up desmosomes; isoforms 1 and 3 targeted by autoantibodies in pemphigus vulgaris
14
Q
papillary dermis
A
superficial layer of the dermis; interdigitates with the rate ridges/pegs of the epidermis, is more cellular than the reticular dermis, and has fine/loosely-woven collagen that runs perpendicular to the dermal-epidermal border
15
Q
reticular dermis
A
deep layer of the dermis; is less cellular than the papillary dermis and has coarse, thick, tightly-packed collagen that runs parallel to the dermal-epidermal border
16
Q
extracellular matrix
A
acellular scaffold that provides structure to a tissue and regulates cell functions such as adhesion, migration, division, and apoptosis; made up of collagen, elastic fibers, and extrafibrillar matrix; main component of the dermis of the skin
17
Q
collagen
A
ECM protein produced by fibroblasts; main subunit is a trimer of alpha-chains containing 3-nucleotide repeats of glycine, proline, and hydroxyproline, which is exported to the extracellular space, cleaved, and assembled into fibers; 28 types exist, 12 are present in skin, type I is most abundant in skin, type III is second-most abundant; type III is more important in embryogenesis and wound healing
18
Q
elastic fibers
A
ECM protein composed of microfibrils made of fibrillin and amorphous elastin; provides skin with elasticity
19
Q
ground substance
A
AKA extrafibrillar matrix; non-collagen, non-elastin component of dermis composed of water, electrolytes, plasma proteins, and proteoglycans
20
Q
fibroblast
A
predominant cell type in the dermis of the skin; derived embryonically from the mesoderm; produces and secretes components of the ECM
21
Q
Pacinian corpuscle
A
specialized sensory receptor located in the deep dermis and subcutaneous tissue of weight-bearing surfaces, lips, nipples, penis, and clitoris; detect pressure and vibration
22
Q
Meissner’s corpuscle
A
specialized sensory receptor located just below the epidermis in the papillary dermis of the palms and soles; detect light touch
23
Q
fibrillin
A
protein component of elastic fibers; mutated in Marfan syndrome
24
Q
subcutaneous fat
A
layer of tissue below the dermis of the skin made up of adipocytes; derived embryonically from the mesoderm; stores energy and provides insulation and shock absorption
25
adipocyte
fat-storing cell located in the subcutaneous fat layer; synthesizes and stores lipids in cytoplasm with nucleus displaced to one edge
26
basement membrane zone
protein layer that provides dermo-epidermal adhesion; regulates cell differentiation, motility, and extracellular signaling
27
hemidesmosome
protein structure of the BMZ located on inner surface of basal keratinocytes that connects them to the ECM; includes hemidesmosomes, lamina lucida, lamina dens, and sublamina dens
28
sunscreen
topical cream that prevents UV radiation from damaging the skin; may contain physical blockers and/or chemical blockers
29
physical blocker
a component of sunscreen that reflects UV radiation; examples include zinc oxide and titanium dioxide
30
chemical blocker
a component of sunscreen that absorbs UV radiation and converts it to heat; examples include para-aminobenzoic acid (PABA), avobenzone, oxybenzone, cinnamates, and salicylates
31
sun protection factor
measure of protection against UVB exposure; MED protected/MED unprotected (i.e., factor by which you can multiply your time in the sun without getting sunburned)
32
lamina lucida
layer of the BMZ found just beneath the hemidesmosomes; may be an artifact of tissue preparation
33
lamina densa
layer of the BMZ composed of type IV collagen and laminins
34
sublamina densa
layer of the BMZ composed of type VII collagen; maintains epidermal-dermal cohesion by binding both type I and type IV collagens
35
BP230 (BP antigen 1)
cytoplasmic protein in the plakin family; contributes to organization of the cytoskeletal architecture; may be targeted by autoantibodies in bullous pemphigoid
36
BP180 (BP antigen 2)
AKA type XVII collagen; transmembrane protein that connects basal keratinocytes and cytoskeleton to dermal collagen VII/laminin 332; may be targeted by autoantibodies in bullous pemphigoid
37
laminin 332
primary BMZ laminin; heterotrimer; binds transmembrane domain of hemidesmosome integrin and to type VII collagen (bridges the BMZ)
38
direct immunofluorescence
diagnostic procedure using a patient perilesional skin sample and fluorescein-conjugated antibodies to detect immunoglobulin or complement in situ
39
indirect immunofluorescence
diagnostic procedure using normal human skin (sometimes split at the lamina lucida by salt), patient serum, and fluorescein-conjugated antibodies to detect circulating antibodies in the patient serum
40
ELISA
enzyme-linked immunosorbent assay; diagnostic procedure used to detect circulating autoantibodies in patient serum
41
hemostasis
first step in cutaneous wound healing; reflexive vasoconstriction occurs in response to damage signals from cells and vessels; mediators include endothelin (from endothelium), catecholamines, and prostaglandins (from injured cells); coagulation cascade is initiated by bradykinin, serotonin, and thromboxane A2
42
inflammation
second step in cutaneous wound healing; involves vasodilation and increased vascular permability mediated by kinins, histamine, prostaglandins, and leukotrienes, followed by leukocyte recruitment
43
proliferation
third step in cutaneous wound healing; involves re-epithelialization of the wound, which begins with epidermal thickening along wound edges; also mediated by fibroblasts (last cell population to enter wound - attracted by PDGF, IGF-1, TGF-beta from platelets), smooth muscle cells, and endothelial cells, which synthesize collagen (allows basal cell migration) and promote angiogenesis
44
maturation
final step in cutaneous wound healing; involves clearance of inflammatory cells from scar tissue, fibroblast apoptosis, blood vessel maturation, and collagen remodeling/maturation
45
Langerhans cell
antigen-presenting cell found in the skin; primarily found in the spinous layer, but present throughout the dermis and epidermis; mesoderm/bone marrow-derived
46
macule
flat, non-palpable skin lesion
47
patch
flat, non-palpable skin lesion > 1 cm in diameter
48
papule
elevated or depressed, palpable skin lesion
49
plaque
elevated or depressed, palpable skin lesion with a broad and flat surface > 1 cm in diameter
50
nodule
palpable skin lesion with a rounded surface > 1 cm in diameter; characteristic of inflammatory acne, indicative of a mixed-inflammatory response (lymphocytes, giant cells, and neutrophils)
51
vesicle
fluid-filled blister
52
bulla
fluid-filled blister > 1 cm in diameter
53
pustule
pus-filled blister; characteristic lesion of inflammatory ache, indicative of a neutrophil-dominant reaction
54
wheal
edematous papillose and plaques that are characteristic of hives
55
erosion
open area of the skin with partial or full loss of epidermis
56
ulcer
open area of the skin with loss of part of the dermis
57
fissure
linear ulcer
58
telangiectasia
dilated blood vessels visible on the surface of the skin
59
petechiae
pinpoint areas of hemorrhage on the skin
60
purpura
area of hemorrhage on the skin; can be flat or elevated
61
pemphigus vulgaris
autoimmune blistering disease caused by autoantibodies against desmosomal proteins (desmoglein 1 and 3); most common in the elderly; symptoms include flaccid, intraepidermal blisters that progress into erosions on mucosal and cutaneous sites; can be fatal; tx includes immunosuppressive rx (i.e. prednisone, azathioprine, mycophenolate mofetil, rituximab)
62
ichthyosis vulgaris
autosomal dominant genetic disease caused by mutations in the profilaggrin gene/defective cornified envelope; symptoms include large scaly areas on the body (particularly on the shins and other extremities), dry skin, hyperlinear palms, and predisposition to atopic dermatitis, allergic rhinitis, food allergies, and asthma
63
Marfan syndrome
autosomal dominant genetic disease caused by mutations in fibrillin; symptoms include tall and thin body type, long limbs/fingers, scoliosis, flexible joints, striae, nearsightedness, lens dislocation, aortic dilation/aneurysm, and mitral valve prolapse
64
Ehlers-Danlos syndrome
group of genetic diseases caused by mutations in the structure, production, processing, or assembly of collagen; symptoms include fragile/super-elastic skin prone to scarring, extremely flexible joints, scoliosis, and ruptured blood vessels/intestines/uterus
65
morphea
autoimmune disease; affects both children and adults, more common in females; symptoms include erythematous and indurated plaques that slowly expand and may cause fibrotic/atrophic scars; may also include joint and neurologic complications
66
systemic sclerosis
autoimmune disease; most common in young to middle-aged women; subtypes include limited systemic sclerosis (CREST syndrome) and diffuse systemic sclerosis; symptoms of limited systemic sclerosis include Calcinosis cutis, Raynaud phenomenon, Esophageal dysmotility, Sclerodactyly, and Telangiectasia of the face; symptoms of diffuse systemic sclerosis include widespread sclerosis of the skin, pulmonary fibrosis, renal failure, GI disease, and cardiac disease
67
erythema nodosum
acquired disorder with multiple causes (i.e. idiopathic, infection, etc.); triggers include upper respiratory strep infection, medications (oral contraceptives), sarcoidosis, IBD, and malignancy; form of panniculitis (inflammation of subcutaneous fat); symptoms include tender, red nodules on the shins that resolve within a few days or weeks
68
bullous pemphigoid
autoimmune bullous disease caused by autoantibodies against BP230 and BP180; most common in the elderly; symptoms include highly pruritic urticaria followed by tense, stable, subepidermal blisters with serous or hemorrhagic content; DIF, linear IgG/C3 deposits along BMZ; IIF, linear staining on epidermal side of split skin; Tx with steroids
69
mucous membrane pemphigoid
autoimmune disease caused by autoantibodies against BP180, BP230, integrin beta4, or laminin 332; most common in the elderly; symptoms include recurrent blistering of mucous membranes and skin, scars, strictures, synechiae, blindness; association with malignancy also seen in those with anti-laminin 332; DIF, linear IgG/C3 deposits along BMZ; IIF, linear staining on epidermal, dermal + epidermal, or dermal side of split skin
70
epidermolysis bullosa acquisita
autoimmune disease caused by autoantibodies against type VII collagen; symptoms include blistering and erosion elicited by any trauma, particularly on mechanically-stressed areas (hands, feet, elbows, knees), atrophy, milia, scars, pigmentation disorders, fibrosis of hands and feet, nail dystrophy, and hemorrhagic erosions of oral mucosa; DIF, linear IgG/C3 deposits along BMZ; IIF, linear staining on dermal side of split skin (no ELISA test)
71
epidermolysis bullosa
genetic disease caused by mutations in BMZ proteins (keratins 5 and 14, pectin, collagen VII and XVII, alph6beta4 integrin, laminin 332); symptoms include blistering and erosion elicited by any trauma, as well as others depending on disease subtype
72
sebaceous glands
glands that produce sebum (triglycerides, fatty acids, squalene, wax, sterols) and are associated with hair follicles (except on vermilion lips, urogenital mucosa, areolae, and eyelids); present in highest density on face and scalp, but are present everywhere on body except palms and soles; sebum secretion occurs continuously and via holocrine secretion under the influence of maternal hormones or androgens
73
vellus hair
fine, short hairs found on most body surfaces; during puberty, some changes to terminal hair under the influence of androgens (beard, axillae, pubic)
74
terminal hair
coarse, dark hair that grows longer than other types of hair; before puberty, found on the scalp, eyelashes, and eyebrows; after puberty, also appears on beard, axillae, and pubic areas
75
anagen
hair growth phase; on the scalp, lasts 2-6 years; at any given time, appx. 85% of scalp hairs are in anagen
76
catagen
hair regression phase; on scalp, lasts 2-3 weeks; at any given time,
77
telogen
hair resting phase; on scalp, lasts appx. 3 months; at any given time, appx. 10-15% of scalp hairs are in telogen
78
eccrine glands
one of the two types of sweat glands; present on all cutaneous surfaces, but found in greatest density on palms and soles; innervated by postganglionic sympathetic fibers controlled by the hypothalamic sweat center using acetylcholine as the principal neurotransmitter; apical portion (acrosyringium) is intraepidermal and drains directly onto cutaneous surface; secrete via merocrine mechanics
79
apocrine glands
one of two types of sweat glands; present on the axillae, anogenital region, periiumbilical region, areolae, nipples, and vermilion border of the lips; secrete oily, viscous fluid that is degraded by cutaneous bacteria into odiferous substances; secretion is controlled by catecholamines and cholinergic agonists (poorly understood); duct opens into the upper portion of the hair follicle; secrete via apocrine mechanics
80
comedone
plugged hair follicles due to increased sebum production and increased production/decreased shedding of corneocytes; characteristic lesions of non-inflammatory acne; may be closed (whiteheads) or open (blackheads)
81
inflammatory papules
one of the characteristic lesions of inflammatory acne; indicates a mixed-inflammatory response (lymphocytes, giant cells, neutrophils)
82
acne cysts
one of the characteristic lesions of inflammatory acne; indicates a mixed-inflammatory response (lymphocytes, giant cells, neutrophils)
83
melanocyte
dendritic cells derived from the neural crest that reside in the stratum basale of the epidermis and produce melanin; density in normal skin is generally one melanocyte to 10 keratinocytes, but may vary with location and degree of sun damage
84
melanin
pigment produced by melanocytes
85
melanosomes
melanin-containing vesicles synthesized by melanocytes, then transferred to neighboring keratinocytes
86
hyperpigmentation
areas of the skin where there is increased pigment
87
hypopigmentation
areas of the skin where there is decreased pigment; presents as leukoderma (white spots); not enhanced by a Wood's light
88
depigmentation
areas of the skin where there is no pigment; presents as leukoderma (white spots); enhanced by a Wood's light
89
ephelides
freckles; commonly appear on fair-skinned individuals in sun-exposed areas; 1-3 mm; darken with sun exposure; indicate UV-induced damage, are a risk factor for development of melanoma
90
solar lentigines
dark brown/black macule due to UV exposure; generally seen later in life and are bigger than ephelides (5-15 mm)
91
dermal melanocytosis
large, blue-gray patch on the lumbosacral region of infants, usually those with darker skin types; caused by melanocytes in the middle to lower dermis; usually fades with age
92
melanocytic nevi
benign proliferations of melanocytes; may be junctional, compound, or intradermal; generally matures from a junctional nevus to a compound nevus to an intradermal nevus
93
cafe-au-lait macule
well-circumscribed, uniformly brown merciless or patches that appear in infancy or early childhood
94
ash leaf macule
leaf-shaped macules; hypopigmented in tuberous sclerosis
95
angiofibroma (adenoma sebaceum)
telangiectatic papules that develop on the central face
96
Shagreen's patch (connective tissue nevus)
??
97
periungual fibroma
telangiectatic papules that develop along the nail folds
98
capillary malformation (Port wine stain)
flat lesions composed of dilated capillaries in the superficial dermis associated with increased levels of VEGF/VEGF-R2; persist life-long
99
infantile hemangioma
benign vascular tumor commonly found in infants made up of endothelial cells; generally have a growth phase in the first few months of life followed by involution
100
fingertip unit
unit for measuring cream/ointment dose; equal to a stripe of medication from the fingertip to the DIP joint, or 0.5 g medication; will cover an area equivalent to an adult palm for two applications
101
vernix caseosa
thick layer of periderm squames, hair, and a paste-like substance secreted by sebaceous glands that protects the embryonic epidermis from the macerating action of the amniotic fluid
102
lanugo hair
fetal hair; generally shed in utero or during the first weeks of life; begins on the eyebrows, lids, upper lip, and chin, but eventually covers the entire body; holds vernix caseosa next to the skin
103
periderm
superficial layer of squamous cells that cover the basal layer of surface ectoderm in the developing embryonic epidermis; major source of amniotic fluid between weeks 12 and 18; after globular secretory projections pinch off in week 20, remaining squames protect the epidermis from amniotic fluid
104
hair placode, bud, follicle
precursor to a hair follicle; originates in the germinative layer of the epidermis due to signals from the dermis (Wnt, FGF, follistatin) and ectoderm (Wnt, Eda); placode cells proliferate and invaginate to form a hair bud, which later transforms into a hair bulb; begins secreting Shh, which induces adjacent mesenchyme to form dermal papilla; ultimate hair follicle is made up of the hair bulb and the epithelial cells connecting it to the base of the epidermis
105
telogen effluvium
acquired condition in which a greater proportion of hair follicles enter telogen phase simultaneously as the result of a stressor, such as pregnancy, fever, surgery, illness, or malnutrition; patients generally lose these hairs about 3 months after the stressor occurs
106
alopecia areata
autoimmune condition characterized by sudden development of round, smooth patches of hair loss; nail changes, such as pitting or rough/brittle texture, may also be seen; differentiated from tine captitis by the absence of erythema, scaling, or pustules; treatment includes topical corticosteroids and intralesional corticosteroids
107
anagen effluvium
acquired condition characterized by hair loss due to medications such as chemotherapy; typically becomes apparent 2-3 weeks after drug administration; hair usually regrows after drug administration ceases
108
acne vulgaris
acquired condition that peaks in adolescence caused by a combination of increased sebum production and increased production/impaired shedding of corneocytes leading to comedone formation; may also involve Propionibacterium acnes (gram +) by promoting follicular rupture and subsequent inflammation
109
rosacea
multifactorial condition believed to be caused by vascular hyperreactivity; symptoms include easy blushing, reddened complexion, papules/pustules, telangiectasia, and phymatous change (swollen/bumpy skin due to overgrown sebaceous glands); distinguished from acne by absence of comedones; treatment is similar to that of acne, esp. topical metronidazole or sodium sulfacetamide
110
vitiligo
autoimmune disorder caused by destruction of melanocytes; symptoms include symmetric depigmented patches on the face (periorifacial), hands, feet, ankles, knees, and elbows; spontaneous repigmentation may occur; tx includes topical corticosteroids or ultraviolet phototherapy
111
albinism
a genetic disorder due to defects in mailing production; symptoms include diffuse depigmentation or hypo pigmentation of the skin and hair, visual symptoms, and increased photosensitivity
112
piebaldism
autosomal dominant genetic disorder characterized by a congenital patch of white hair and white areas on the skin due to an absence of melanocytes; depigmented areas are stable (not progressive); white patches are most common on central anterior trunk, mid-extremities, central forehead, and mid frontal scalp; may have hyper pigmented macules within them
113
Wardenburg syndrome
autosomal dominant or recessive genetice disorder caused by mutations in Pax3 (or other genes, depending on the form); symptoms include hair/skin chroma, congenital deafness, partial or total heterochromia irides, medial eyebrow hyperplasia, broad nasal root, and dystopia canthorum
114
Neurofibromatosis type I
autosomal dominant genetic disorder caused by mutations in the NF1 gene (neurofibromin); symptoms include multiple cafe-au-lait macules, axillary and inguinal freckling, neurofibromas (soft/rubbery papules on the skin), and plexiform neurofibromas (larger plaques, "bag of worms" feel)
115
Tuberous sclerosis
autosomal dominant genetic disorder caused by mutations in TSC1 and TSC2 (hamartin and tuberin); symptoms include benign tumor formation in multiple organ systems, facial angiofibromas, periungual fibromas, and hypomelanotic macules
116
Sturge-Weber syndrome
congenital developmental disorder of unknown cause; symptoms include a capillary malformation on the forehead in the V1 region, underlying calcifications of the cerebral cortex, seizures, and glaucoma (in ipsilateral eye)
117
PHACE syndrome
congenital disorder of unknown etiology; symptoms include Posterior fossa brain malformations, Hemangiomas of the face, Arterial cerebrovascular anomalies, Cardiovascular anomalies (i.e. coarctation), and Eye anomalies
118
psoriasis
immune-mediated, polygenic skin condition; characteristic lesions are well-demarcated erythematous papules and plaques with overlying micaceous or silvery scale; variants include plaque psoriasis, guttate psoriasis, erythrodermic psoriasis, and pustular psoriasis; plaque psoriasis generally is symmetric and involves extensor elbows and knees, sometimes nail changes; may progress to psoriatic arthritis and increase risk of metabolic syndrome and atherosclerosis; tx includes topical corticosteroids, retinoids, coal tar derivatives, calcineurin inhibitors, topical vitamin D analogues, phototherapy, or systemic immunosuppressive drugs
119
atopic dermatitis
most common chronic inflammatory skin disease caused by many factors, including genetics (including profilaggrin mutations), epidermal barrier dysfunction, and immunopathology; characteristic lesions are edematous, erythematous papules and plaques that may ooze and progress to a scaly/crusted state or lichenification; itchy and dry; most common on face/cheeks and extensor extremities in infancy and flexure areas in adolescence; lesions are less well-defined than those of psoriasis; associated with allergic rhinoconjunctivitis and asthma; can be aggravated by secondary infection with S. aureus or herpes simplex; tx includes topical corticosteroids, regular moisturizing regimen, avoidance of triggers, topical calcineurin inhibitors, phototherapy, and immunosuppressants; antihistamines may be used to relieve itching
120
seborrheic dermatitis
inflammatory skin condition thought to be caused by Malassezia furor, sebum production, and skin surface lipids; symptoms include greasy, yellow scale; in infants, located on scalp ("cradle cap"), though may spread to intertriginous areas, and is self-limiting; in adults, occurs in areas of high sebum production (scalp, face, upper chest); associated with pruritic, but more diffuse and ill-defined than psoriasis; tx includes gentle skin care/emollients, topical corticosteroids, and ketoconazole
121
lichen planus
idiopathic inflammatory disease of the skin and mucous membranes; most common in middle-aged adults; may be due to T-cell-mediated damage to basal keratinocytes; associated with drugs, viruses, and vaccines; characteristic lesions include small, polygonal-shaped, violaceous, flat-topped papules that are pruritic (five "P"s: purple, polygonal, pruritic, planar papules/plaques); may also exhibit Wickham's striae; common on flexural wrists and forearms, tops of hands, shins, and orogenital mucosa; tx includes topical corticosteroids, antihistamines, phototherapy, and immunosuppressive tx
122
congenital ectodermal dysplasia
a group of genetic syndromes that cause alterations in two or more structures that derive from the embryonic ectoderm; symptoms include defects in hair, teeth, nails, sweat glands, and the lens of the eye; most common form is hypohidrotic ectodermal dysplasia, which is caused by mutations in EDA-A1, EDAR, and EDARADD
123
topical retinoids
mainstay drug for acne treatment; examples include tertian, adapalene, and tazarotene; targets comedones by normalizing follicular keratinization, expelling existing keratinaceous follicular plugs, and preventing the formation of new lesions
124
benzoyl peroxide
topical anti-inflammatory agent used in the treatment of acne by targeting both P. acnes and inflammation; resistance is uncommon
125
clindamycin
topical antibiotic agent used in the treatment of acne by targeting both P. acnes and inflammation; frequently leads to the development of resistance; may be used in combination with benzoyl peroxide to prevent resistance
126
doxycycline
oral antibiotic agent used in the treatment of acne
127
minocycline
oral antibiotic agent used in the treatment of acne
128
topical corticosteroids
topical treatment used for a wide variety of inflammatory and autoimmune skin disorders; belong to the glucocorticoid family of steroids; most commonly-used medications in dermatology; side effects include hypo pigmentation, hypertrichosifs, skin atrophy, telangiectasia, and striae
129
ketoconazole
topical anti-fungal used in the treatment of seborrheic dermatitis
130
coal tar
used in topical treatments for psoriasis
131
methotrexate
systemic immunosuppressive drug used in the treatment of psoriasis, atopic dermatitis, lichen plans
132
isoretinoin
systemic retinoid used in the treatment of skin disease
133
acitretin
systemic retinoid used in the treatment of skin disease
134
etanercept
biologic used in the treatment of psoriasis that inhibits TNF-alpha
135
adalimumab
biologic used in the treatment of psoriasis that inhibits TNF-alpha
136
infliximab
biologic used in the treatment of psoriasis that inhibits TNF-alpha
137
ustekinumab
biologic used in the treatment of psoriasis that targets IL-12 and IL-23
138
pimecrolimus
calcineurin inhibitor that can be used topically in the treatment of psoriasis, atopic dermatitis
139
tacrolimus
calcineurin inhibitor that can be used topically in the treatment of psoriasis, atopic dermatitis
140
vitamin D analogs
used topically in the treatment of psoriasis to induce terminal differentiation and inhibit proliferation of keratinocytes; also modulates the immune response
141
pilosebaceous unit
consists of a hair follicle and its associated sebaceous gland; hair follicle consists of the hair bulb (inferior segment below the arrector pili muscle), isthmus (middle segment, from point of insertion of arrector pili muscle to the sebaceous gland), and infundibulum (upper segment, between skin surface and sebaceous gland)
142
CDKN2A
gene that harbors an inherited mutation in 40% of families with familial dysplastic nevus syndrome/familial melanoma
143
BRAF
gene that often harbors an activating mutation in melanoma; V600E is most common variation; typically associated with a poor prognosis in melanoma, colorectal cancer, and papillary thyroid carcinoma
144
Breslow thickness
a measurement, in millimeters, of the depth of vertical invasion of a melanoma lesion; single most important prognostic indicator
145
epidermotropism
tendency of T-cells to colonize the epidermis observed in mycosis fungoides T-cell lymphoma; may be lost in tumor stage of disease
146
Staphylococcus aureus
common causal organism of impetigo; phage group II can cause bullous impetigo; phage group II, type 71 may be toxigenic and produce ET-A and ET-B, which cause SSSS
147
Streptococcus pyogenes
common causal organism of impetigo
148
Epodermolytic toxin A/B
exotoxins produced by phage group II, type 71 Staph aureus that lead to pathologic changes associated with SSSS; cause intraepidermal splitting through the granular layer
149
Sarcoptes scabiei
arthropod that causes scabies; acquired through close personal contact or sexual contact; characterized by papules/burrows between the fingers or on sides of fingers; papules may be excoriated and secondarily infected; tx includes permethrin or oral anti-scabetics
150
trichophyton
genus of fungi that commonly causes dermatophytoses; invades epidermal keratin and hair
151
epidermophyton
genus of fungi that commonly causes dermatophytoses; invades epidermal keratin
152
microsporum
genus of fungi that commonly causes dermatophytoses; invades epidermal keratin and hair
153
human papilloma virus
DNA virus in the papovavirus family; causes a variety of warts, including verruca vulgaris, filiform warts, verruca plan, plantar warts, anogenital warts, and bowenoid papulosis
154
Malassezia globosa
causal organism of most cases of tinea versicolor
155
seborrheic keratosis
benign lesion developing in the middle-aged and elderly; numerous, sharply-delineated, round, skin-colored or brown-black warty papules; primarily on trunk and face; may harbor mutations in FGF-R3; sign of Leser-Trelat involves sudden onset of multiple seborrheic keratoses in association with internal malignancy
156
actinic keratosis
dysplastic lesion due to UV light injury; some become malignant; rough, erythematous or yellow-brown, scaly; common in middle-aged and elderly; treated surgically and medically
157
squamous cell carcinoma
tumor caused by combination of sunlight, industrial carcinogens, chronic ulcers, burn scars, arsenicals, ionizing radiation, HPV infection, and immunosuppression; presents as irregular in shape, erythematous and scaly/crusted; invasive lesions may be nodular and/or ulcerated; only 5% become invasive; treated surgically or with topical meds
158
keratocanthoma
variant of squamous cell carcinoma; solitary, pink or flesh-colored, dome-shaped nodule with central keratin plug; grows rapidly for 2-10 weeks, followed by stationary period and involution; generally treated to prevent local destruction
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basal cell carcinoma
most common cutaneous malignant neoplasm; most common in elderly males on sun-exposed areas; commonly harbors mutations in PTCH1; presents as a papule with pearly, translucent edge with visible telangiectasia, usually slow-growing and non-aggressive; histology shows characteristic clefting between tumor nodules and surrounding stroma
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melanocytic nevus
lesion of hyperplastic melanocytes that is well-circumscribed with a regular border and regular pigmentation (central area may be darker); may be junctional (round "nests" along the dermal-epidermal junction), compound (nests or cords in the dermis), or intradermal
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dysplastic nevus
nevi that are larger than acquired nevi, irregular in shape, and have uneven color with dark centers; either junctional or compound, may exhibit abnormal fusion with adjacent cells, tend to replace the normal basal cell layer along dermal-epidermal junction ("lentiginous hyperplasia"); may also have irregular, often angulated, nuclear contours and hyperchromasia; appear on non-sun-exposed areas; people who have multiple dysplastic nevi are at increased risk for melanoma
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dysplastic nevus syndrome
familial or sporadic occurrence of multiple dysplastic nevi (80 or more); familial variant caused by autosomal dominant mutation (incomplete penetrance) of CDKN2A; associated with increased risk of neoplasms, including melanoma and pancreatic cancer
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lentigo maligna melanoma
subtype of melanoma; occurs in sun-damaged areas of the skin in older individuals; most common on head, neck, and arms; in situ lesion may exist for 10-15 years before becoming invasive
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superficial spreading melanoma
most common subtype of melanoma; most common on trunk in men and legs in women
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hydroxyzine
sedating, classic H1 antihistamine
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nodular melanoma
subtype of melanoma; has a high vertical growth phase and no radial growth phase; poor prognosis; more common in females and on the trunk and legs
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acral lentiginous melanoma
lease common subtype of melanoma in white individuals, most common subtype in African-Americans, Asians, and Hispanics; most common on palmar, plantar, sublingual, and mucosal surfaces, and in older females
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mycosis fungoides
T-cell lymphoma; most common cutaneous lymphoid malignancy; most common in males, in blacks, and in the 4th-6th decades; begins with patch stage, characterized by nonspecific dermatitis on the lower trunk and buttocks, includes ill-defined patches with fine scale and irregular size/shape; followed by plaque stage, characterized by well-demarcated, often annular, violaceous, scaly lesions; final stage is tumor stage, characterized by development of pre-existing lesions into red, tense, shiny, possibly ulcerated lesions; prognosis varies widely, depends upon stage and extent of body surface coverage; characterized by Sezary/mycosis T-cells that are large, convoluted, cerebriform nuclei in the epidermis; Sezary syndrome is rare variant, characterized by erythroderma, blood involvement, and poor prognosis
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warts (verrucae)
skin lesions caused by infection of HPV, a DNA virus of the papovavirus family; verruca vulgaris appears mostly on the hands, verruca plana is most common on face or dorsal hands, and verruca plantaris/palmaris is on the soles and palms; generally spontaneously regress after several years, but may be treated surgically or topically
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cellulitis
deep pyogenic skin infection characterized by diffuse inflammation of the connective tissue of the skin and/or deep soft tissues; symptoms include expanding erythema that is edematous and tender, usually has neutrophil infiltrate; most commonly caused by beta-hemolytic streptococci or coagulase-positive staphylococci; subtype erysipelas has an elevated border and spreads rapidly
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Staphylococcal scalded skin syndrome
exfoliative dermatitis caused by ET-A/ET-B secreted by certain S. aureus sub-types; common in infants and young children due to outbreaks in nurseries/daycare centers; may occur in adults with renal disease; symptoms include skin tenderness, macular eruption, flaccid bullae, desquamation of large areas of skin, generally on the face, neck, and trunk (spares mucous membranes); tx includes oral antibiotics
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condyloma acuminatum
warty skin lesions caused by HPV 6 and 11 (most commonly) as a consequence of trauma accompanying sexual intercourse; high-risk types (16, 18, 31, 33) may increase risk of cancer; presents as single or multiple papular eruptions that appear pearly, filiform, fun gating, cauliflower, or plaquelike; treated the same way as other types of warts
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Herpes simplex
dsDNA virus that causes herpes labialis (HSV-1) and herpes genitalis (HSV-2); herpes labialis typically occurs in childhood and exhibits lesions on the lips, oral cavity, pharynx, etc., vesicles may be preceded by tingling sensation; HSV-1 is transmitted via direct contact with saliva, HSV-2 is transmitted sexually; latent infection can be re-stimulated by UV light, trauma, fever, HIV infection, menstruation, and stress; dx via Tzanck smears PCR, and biopsy
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Varicella zoster
virus that causes Chickenpox and shingles; chickenpox is characterized by widespread vesicles in multiple stages of development (papules, vesicles, pustules, crusted lesions, healing lesions) that are all present simultaneously; shingles occurs due to reactivation of latent virus later in life, is characterized by vesicular eruption in dermatomal distribution (most common on thoracic and lumbar regions) that is preceded by paresthesia/pain
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Molluscum contagiosum
cutaneous infection caused by a poxvirus (DNA, brick-shaped) that is transmitted by direct skin contact; presents with solitary or multiple dome-shaped, umbilicate, waxy papules, most commonly on head/neck, trunk, and genitalia of children and adolescents; resolves spontaneously, though optional treatment is similar to that of warts
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dermatophytosis
cutaneous fungal infection caused by filamentous fungi that invade and colonize keratinized tissues
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tinea capitis
dermatophytosis characterized by scaly patches on the scalp
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tinea corporis
dermatophytosis characterized by scaly, annular, erythematous patches on the body
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tinea mannum
dermatophytosis characterized by erythema and scale of the hands
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tinea pedis
dermatophytosis characterized by erythema and scale of the feet
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tinea unguium
AKA onychomycosis; dermatophytosis characterized by thickened, yellow nails
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onychomycosis
AKA tinea unguium; dermatophytosis characterized by thickened, yellow nails
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tinea cruris
dermatophytosis characterized by erythematous, macerated patches of the groin
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tinea versicolor
cutaneous fungal infection common in tropical climates, young adults, females caused by Malassezia globosa, M. furor, or M sympodialis; presents as multiple irregular areas of hypo- or hyperpigmentation that are circular, macular, and confluent; tx includes topical or oral antifungals
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acanthosis nigricans
cutaneous manifestation of insulin resistance (i.e. T2DM); may also be seen in familiar cancer syndromes; characterized by brown, velvety plaques on the posterior neck, axillae, and groin
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diabetic dermopathy
idiopathic cutaneous condition seen in some diabetic pts; characterized by brown, atrophic macule on the shins; may be associated with trauma; marker for poor diabetes control
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necrobiosis lipoidica diabeticorum
cutaneous condition in diabetic pts; characterized by yellow-orange, atrophic patches on the shins that expand and may ulcerate; no association with diabetes control
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diabetic bullae
cutaneous condition in diabetic pts; characterized by bullae that spontaneously appear on the hands, legs, and feet; generally self-resolve and recur; more common in men and those with long-standing disease or complications
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hypothyroidism
decreased activity by the thyroid gland that may have cutaneous symptoms; includes cold, dry, rough skin; brittle hair and nails; alopecia of the lateral third of the eyebrows
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hyperthyroidism
increased activity by the thyroid gland that may have cutaneous symptoms; includes fine, velvety, smooth skin that is warm and moist; fine and thin hair (sometimes alopecia); predibial myxedema on the shins (bilateral, firm, nonpaying, shiny, pink plaques)
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Addison's disease
caused by chronically low corticosteroid levels and has cutaneous symptoms, including hyperpigmentation, with accentuation in sun-exposed areas, mucous membranes, skin creases, and sites of trauma
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Cushing's syndrome
caused by chronic supraphysiological corticosteroid levels and has cutaneous symptoms, including abnormal fat distribution, skin atrophy (striae, fragility, purpura), hirsutism, steroid acne, and increased propensity for cutaneous infections
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porphyria cutanea tarda
acquired or genetic disease caused by decreased activity of urophorphyrinogen III decarboxylase (UROD); symptoms include vesicles that heal with scarring on sun-exposed areas and hypertrichosis of the temples and malar cheeks
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discoid lupus erythematosus
cutaneous presentation of lupus (may be associated with SLE, but usually skin-limited); characterized by hyperkeratotic, violaceous plaques on the head and neck (esp. scalp and ears) that heal with atrophic scars
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subacute cutaneous lupus erythematosus
cutaneous presentation of lupus characterized by pink, scaly plaques on sun-exposed areas such as the face, upper chest, and arms; may be annular
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dermatomyositis
autoimmune disease characterized by inflammation of the skin and muscle; symptoms include symmetric proximal muscle weakness and photosensitive skin lesions, including heliotrope rash, shawl sign (pink scaly patches on chest/shoulders/back), Gorton's papules (pink-purple, flat-topped papules on elbows, knees, and dorsal hands and feet); may also exhibit periungual erythema and ragged cuticles
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sarcoidosis
condition characterized by noncaseating granulomas in multiple organ systems; may present in skin as pleomorphic, red-brown macule and papules on the face, esp. around eyes and nose; may also be associated with erythema nodosum
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dermatitis herpetiformis
autoimmune blistering disease caused by gluten sensitivity; most common in young adult men of Norther European descent; characterized by intensely pruritic vesicles that lead to excoriations and erosions; common on extensor surfaces (buttocks, elbows, knees); tx includes dapsone and gluten-free diet
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urtricaria
AKA hives; characterized by pink edematous papules and plaques that are migratory and transient; caused by IgE-mediated immediate hypersensitivity; acute cases may be idiopathic, due to upper respiratory infection, or drug-induced; tx includes oral antihistamines (combination of non-sedating with sedating classic)
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exanthematous drug reaction
AKA morbilliform drug rashes; caused by type IV delayed hypersensitivity; characterized by monomorphic macule and thin papules, beginning on the face and trunk then spreading to the extremities; generally associated with pruritis and/or low-grade fever; appears 2-14 days after drug initiation; generally spontaneously-resolving, tx includes topical corticosteroids and oral antihistamines
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DRESS
drug reactions with eosinophilia and systemic symptoms; resembles exanthematous drug eruptions, but usually includes fever; also associated with facial edema, enlarged lymph nodes, and arthralgias; may have systemic involvement, indicated by elevated liver enzymes, myocarditis, pneumonitis, nephritis, thyroiditis, and brain involvement; tx includes discontinuation of suspected drug cause and systemic corticosteroids
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erythema multiforme
cutaneous condition triggered by infection (herpes simplex virus) or drugs; characterized by targeted lesions with dusky center on acral areas and ocular/oral/genital mucosa; self-resolves within a few weeks, tx includes symptomatic treatment of itching/pain or systemic corticosteroids for severe disease
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Stevens-Johnson syndrome
life-threatening cutaneous reaction to drugs (allopurinol, NSAIDs, sulfa drugs, anticonvulsants, abx) that may overlap with TEN; symptoms include fever, malaise, and upper respiratory symptoms, followed by painful red patches that evolve into bullae and necrotic areas; lesions may appear on any mucosal surface; SJS defined by epidermal detachment on
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toxic epidermal necrolysis
life-threatening cutaneous reaction to drugs (allopurinol, NSAIDs, sulfa drugs, anticonvulsants, abx) that may overlap with SJS; symptoms include fever, malaise, and upper respiratory symptoms, followed by painful red patches that evolve into bullae and necrotic areas; lesions may appear on any mucosal surface; TEN defined by epidermal detachment on >30% body surface area; tx includes discontinuation of causal drug and supportive care
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Henoch-Schonlein purpura
small vessel vasculitis most common in children; biopsy looks similar to leukocytoclastic vasculitis, but also exhibits IgA immune complexes; may be triggered by infection; characterized by palpable purpura, esp. on buttocks and lower extremities; also arthritis, abdominal pain, GI bleeding, and nephritis; self-limited, resolves in 2-4 weeks
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leukocytoclastic vasculitis
small vessel vasculitis of the skin when neutrophils are the predominant inflammatory cell seen on biopsy; may be idiopathic or triggered by infection or drug hypersensitivity; characterized by palpable purpura, urticarial lesions (more permanent than true urticaria), nodules, ulceration, and livedo reticular, primarily on the legs
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vemurafenib
inhibitor of V600E-mutant form of BRAF; helpful in the treatment of metastatic melanoma
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imiquimod
topical treatment for warts that stimulates the immune system through toll-like receptor 7
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loratidine
non-sedating H1 antihistamine
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cetirizine
non-sedating H1 antihistamine
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fexofenadine
non-sedating H1 antihistamine
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diphenhydramine
sedating, classic H1 antihistamine
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impetigo
superficial bacterial skin infection spread by direct contact and caused by S. aureus or S. pyogenes; presents as vesicles with honey-colored crust; common on mouth, nose, and extremities and in humid conditions; bullous form may develop due to phage group II S. aureus; tx includes topical or oral antibiotics
