Dermatology Flashcards
1
Q
Skin + UVB=
A
Cholecalciferol (Vitamin D3)
2
Q
The liver converts Vitamin D3 into
A
Calcidiol (25-hydroxy Vitamin D)
3
Q
The Kidneys convert 25 hydroxy Vitamin D (Calcidiol) into
A
active 1,25 dihydroxy Vitamin D (Calcitriol)
4
Q
Fitzpatrick Skin Types I and II
A
I. Never tans, always burns
II. Tans with difficulty, usually burns
5
Q
Fitzpatrick skin types III and IV
A
III. Average tanning, sometimes burns
IV. Easily tans, rarely burns
6
Q
Fitzpatrick skin types V and VI
A
V. Very easy to tan, very rarely burns
VI. Never burns
7
Q
Types of cells present in the epidermis
A
Keratinocytes, Langerhans cells, Melanocytes
8
Q
Two types f melanin produced by melanocytes
A
Eumalanin: black to brown pigment
Pheomelanin: yellow to red-brown pigment
9
Q
Skin pigmentation is due to:
A
TYPE OF MELANIN PRODUCED,
AS WELL AS SIZE AND DISTRIBUTION OF MELANOSOMES
10
Q
Distribution of melanosomes in Light skin vs dark skin
A
in light skin, the melanosomes are smaller and are distributed in clusters above the nucleus in the keratinocyte, in dark skin, the melanosomes are larger and distributed individually throughout the cytoplasm of the keratinocyte
11
Q
The absence of melanocytes is called _____. Where is it commonly seen?
A
Vitiligo, commonly seen in periorifacial and acral locations
12
Q
Layers of the epidermis
A
Stratum corneum
Stratum granulosum
Stratum spinosum
stratum basalis
13
Q
How long does renewal of the epidermis take?
A
28 days
14
Q
Hemidesmosome
A
Attachment point of basal cells to the basal lamina of the dermal epidermal junction
15
Q
Bullous Pemphigoid
A
Autoantibodies to BP180 (type XVII collagen) or BP230, both found int he hemidesmosomes. Causes subepiderman blisters and tense bulla. Most common autoimmune bullous disorder. Treatment: prednisone
16
Q
keratin,
A
a tough protective protein that makes up the majority of the structure of skin, hair and nails. MAde by keratinocytes of the epidermis
17
Q
Desmosomes
A
structuresfor cell to cell adhesion (macula adherens)
• Contain intracellular keratin filaments and transmembrane proteins, desmogleins and desmocollins
18
Q
Acquired antibodies to desmoglein 1 and desmoglein 3 cause ____ _____
A
pemphigus vulgaris
19
Q
Pemphigus Vulgaris
A
-Primary skin lesions are flaccid bulla (Nickolsky sign positive)
-Pathology: Intraepidermal blisters
• painful oral erosions
• Other mucous membranes can be involved (eyes, GI and GU mucosa)
• Treatment: Prednisone or other immunosupressives
20
Q
What cell layer do the cells start to lose their nuclei?
A
Statum granulosum
21
Q
What do the granules of keratinocytes contain?
A
keratohyalin granules contain filaggrin, which X-links keratin, lamellar bodies excrete ceramics
22
Q
What is the stratum corneum composed of? What keeps it moist?
A
dead and desquaming keratinocytes. Natural moisturizing factor (NMF) keeps it moist
23
Q
Patients with ______ mutations have significantly reduced levels of the NMF in the stratum corneum and exhibit increased _______ water loss
A
filaggrin
transepidermal
24
Q
Merkel cells
A
Small cells associated with nerve endings in epidermis. Their function has long been uncertain, but they seem to be involved in neural development and tactile sensation. Recent evidence supports a role for Merkel cells in light touch
25
Macule
Flat area of color change
Less than 1.0 cm
Can be hyper pigmented or hypopigmented
26
Patch
Flat area of color change
Greater than 1.0 cm
Can be hyper pigmented (think cafe au lait spot) or hypopigmented
27
Papule
Discrete,solid,elevatedbody
• Less than 1 cm in diameter
• May be further classified by surface change
– Scale, Crust
28
Plaque
* Solid,flat-topped,elevated area of skin
* Greater than 1cm and broader than thick
* May be further classified by surface change
29
Nodule
* Firm and well-defined lesion
* May be dermal or subcutaneous
* Greater than 1.0 cm
30
Scale
* Excess stratum corneum (outermost layer)
* May appear as flakes or plates
* Color usually white or gray
31
Crust
• Dried blood, serum or purulent exudate that
forms on the skin surface
• May be thick or thin
• Color determined by type of dried fluid
32
Vesicles
* Fluid filled cavity or elevation
* Form within or just below epidermis
* Less than 1.0 cm in diameter
33
Bulla
* Fluid filled "blister"
| * Greater than 1.0 cm in diameter
34
Pustule
* Circumscribed elevation that contains pus
* Less than 1.0 cm in diameter
* Color usually whitish-yellow
35
Erythema
* Localized, blanchable redness
| * Caused by increased blood flow
36
Erythroderma
* Generalized, blanchable redness
* Caused by increased blood flow
* May be associated with desquamation or extensive scaling
37
Telangiectasias
• Visible, persistent, dilation of small, superficial cutaneous blood vessels
38
Palpable purpura
• Raised and palpable discoloration
• Due to vascular inflammation and
extravasation of red blood cells (vasculitis)
• Color is red or violaceous
39
Erosion
* Localized loss of epidermal or mucosal epithelium
| * Causes can include injury or denuding of vesicle or bulla roof (removal)
40
Ulcer
• Circumscribed loss of epidermis and at least upper dermis
– Depth: can extend to subcutaneous, muscle or
bone areas
– Edge: clean, ragged, undermined
– Tissue at base: necrotic, purulent or healthy granulation tissue
41
Eschar (crust)
•"Scab"
• Adherent,thick,dry crust
• Causes: trauma, infection, or excoriating skin disease
• Black
42
Intertriginous distribution
Regions where opposing skin surfaces come in contact that may cause friction
43
Flexural distribution
• Pertaining to the skin surface overlaying muscles that flex joints, such as biceps
44
Does the epidermis contain blood vessels?
The epidermis contains no blood vessels, it depends upon the dermis for all its nutritional support.
45
The dermis also provides the _____, _____ and _____ of the skin
strength, resiliency and plasticity
46
Two zones of the dermis
: a) the papillary dermis (located immediately beneath the epidermis), and b) the reticular dermis located deeper in the tissue.
47
Dermal matrix consists of
mixture of collagen fibers, elastic fibers and ground substance all of which are synthesized by dermal fibroblasts.
48
skin appendages or adnexal structures
hair follicles, sebaceous glands (oil glands), and sweat glands found in the skin that are vital to protection and homeostasis.
49
dermal papillae
The downward projections of epidermis interdigitate with upward projections of the dermal papillae
50
What is the main function of collagen in the skin?
It provides essentially all the tensile strength of the skin.
51
What type of collagen comprises >85% wt % of the adult dermis?
Collagen I
52
What type of collagen is present in large quantities in the fetal dermis?
Collagen III
53
Structure of collagen
three chains of proteins arranged in an α-helical structure, electron microscope yields a characteristic pattern of striations with 68 nm intervals. The chains consist of repeated strings of glycine and two other proteins, forming a Gly-X-Y structure. The X and Y are usually proline and hydroxyproline.
54
Where/how is collagen synthesized?
The synthesized collagen proteins are secreted and then are assembled into collagen fibrils EXTRACELLULARLY.
55
classic example of an acquired abnormality in collagen production
Scurvy
56
Ehlers-Danlos syndrome (EDS)
genetic disorders of collagen synthesis, all of the subtypes share 4 major clinical features including:
* skin hyperextensibility
* joint hypermobility
* tissue fragility
* poor wound healing
57
Collagen fibers provide the skin with tensile strength, but elastic fibers provide the skin with ________
resiliency
58
elastic fibers are ______ (silver-loving) and special silver stains (such as the ______) may be performed to accentuate the presence of elastic fibers
argyrophilic
| Verhoff-Van Gieson stain
59
The most common acquired disorder of elastic is
solar elastosis
Over a lifetime, a person accumulates sunlight exposure, leads to degeneration of the elastic. collagen bundles become dystrophic tend to “clump”sun-damaged elastic fibers become easy to appreciate on routine microscopy, as basophilic (blue) staining material within the superficial portions of the dermis.
60
pseudoxanthoma elasticum (PXE)
caused by mutation in a gene encoding part of the “multidrug resistance complex”, responsible for pumping compounds out of cells. The elastic fibers of the dermis become enlarged, tangled, calcified--> characteristic purple-blue color on histo. Skin of the flexural areas= “plucked chicken." Elastic fibers of the blood vessels are also damaged leading to hypertension and bleeding disorders, particularly in the eye.
61
Ground substance
a gelatinous material intercalated between and amongst the collagen bundles, elastic fibers, and appendageal structures of the dermis. It consists principally of two glycosaminoglycans: hyaluronic acid and dermatan sulphate.
62
Is ground substance static?
No, ground substance is constantly being destroyed, by enzymes like hyaluronidase, and then renewed via production from fibroblasts
63
Restylane
pure hyaluronic acid, placed under skin to augment the tissue and remove lines. It is well-suited for this purpose for two reasons: a) it is a natural substance that is already present in the skin and it does not engender an immune response (unlike some bovine collagen fillers) and b) it absorbs a tremendous amount of water and amplifies the augmentation. Just like endogenously produced hyaluronic acid, Restylane is broken down by tissue hyaluronidases and it is not a permanent augmentation.
64
verruca
warts. They are benign, virally induced neoplasms (growth) that require an increased blood supply simply to support the virally-proliferating cells. These proliferating vessels may be identified as brownish, thrombosed capillary structures in the center of the verruca
65
leukocytoclastic vasculitis. How does it manifest clinically?
A common disease involving the post-capillary venules due to the precipitation of immune complexes in the walls of vessels.
. Clinically, vasculitis manifests as “palpable purport” (non blanch able). PMNs attach to vessel wall and degranulate, yielding damage and the extravasation of RBCs into the dermis. This deposition in the vessel walls, w/ infiltrating neutrophils and PMNs debris is called leukocytoclasia.
66
Free nerve endings pass through the upper dermis to terminate at the:
dermoepidermal junction
67
Nerves and conduction rate of pruitus
slow, umyelinated C fivers
68
Pacinian corpuscles
are structures which resemble an onion in cross-section. They are involved in pressure and vibratory sensation. most concentrated in the genital area.
69
Meissner’s corpuscles
resemble a pine-cone and are thought to be involved in fine touch and tactile discrimination. Such receptors are in highest concentration on the distal aspects of the digits, particularly the pulps of the fingers
70
Terminal Hairs
large, thick, coarse, pigmented. Ex: scalp, a man’s beard area and possibly chest/back, and the pubic area, begin deep in the dermis at/near the dermal-subcutaneous junction.
71
Vellus Hairs
small, fine, and apigmented. Such hairs are located diffusely on the body, and represented the types of hairs often on the ear, the lateral face of women, and the body in general.
72
It is common to divide the hair follicle into thirds:
infundibulum=upper third
isthmus= middle third (from the sebaceous duct to the insertion of the arrector pili)
martial area= lower third.
73
Phases of hair life cycle
~85%-anagen (the growth phase),
10-15% telogen (the resting phase)
(1-5%) in catagen (transition phase between anagen and telogen)
74
androgenic alopecia
hairs become miniaturized, finer and lie higher in the dermis. Ultimately they come to resemble vellus hairs. Conversion of testosterone to 5-dihydrotestosterone is important in promoting this change
75
treatments of male pattern baldness
finasteride, a 5-α-reductase inhibitor
| minoxidil, a drug known to promote the anagen phase
76
holocrine gland
(sebaceous glands are and example) the method of secretion involved entire sebocytes (sebaceous gland cells) being secreted and in the process breaking-down to extrude the contents.
77
Acne is a ubiquitious disorder of the _______ unit
pilosebaceous
78
comedones
Blocked pores that are further classified to be: open - “black heads” or closed - “white heads”.
79
Eccrine glands
“general sweat glands”. The primary function of the eccrine unit is thermoregulation, which is accomplished through the cooling effects of evaporation of this sweat on the skin surface.
80
Merocrine glands/secretion
secrete WITHOUT either the apocrine blebbing, or holocrine shedding. Eccrine glands are a classic example of a merocrine secretion.
81
that even though sweating is mediated by the _____ portion of the autonomic nervous system it is triggered via _______ secretion. This is a chemical otherwise associated with the ________ nervous system.
sympathetic
acetylcholine
parasympathetic
82
Apocrine glands
outgrowths of the upper bulge of the primitive ectodermal germ, a fetal structure which yields the follicular unit. The apocrine glands are located only in the axillary and anogenital area.
83
Specialized variants of apocrine glands include
Moll's glands on the eyelids, the cerumen (ear wax) glands of the external auditory canal, and the lactation glands of the breasts. At puberty, hormonal stimulation causes apocrine glands to become functional, and the glands respond mainly to sympathetic adrenergic stimuli initiated by emotional stress.
84
The predominant mode of apocrine secretion is
decapitation, a process where the apical portion of the secretory cell cytoplasm pinches-off and enters the lumen
85
Apoeccrine glands
hybrid sweat glands that are found chiefly in the axilla. Apoeccrine glands may play a role in axillary hyperhidrosis. These hybrid glands have both a small diameter portion, similar to an eccrine gland, and a larger diameter portion that resembles an apocrine gland. Similar to eccrine glands, they respond mainly to cholinergic stimulihybrid sweat glands that are found chiefly in the axilla. Apoeccrine glands may play a role in axillary hyperhidrosis. These hybrid glands have both a small diameter portion, similar to an eccrine gland, and a larger diameter portion that resembles an apocrine gland. Similar to eccrine glands, they respond mainly to cholinergic stimuli
86
Which secretes more, an apoeccrine gland or an eccrine glands
apoeccrine glands secrete nearly ten times as much sweat as eccrine glands
87
hyperhidrosis
focal excessive sweating. may be eccrine, particularly “clammy hands” or “sweaty feet, or may be due to apoeccrine glands in the axilla. generally do not sweat during sleep, most authorities consider it a disease of autonomic dysfunction.
88
What is an ointment comprised of?
water in and oil emulsion
89
What is the potency of an ointment? Is it hydrating or drying? what is the irritation risk?
Ointments are HIGH potency
HYDRATING
LOW irritation risk
90
Where can ointments be used?
Use in non-intrigenous sites.
| Do not use on face, hands, groin
91
A cream is comprised of….
Oil in water emulsion
92
Cream:
- potency
- hydration
- sensitization risk
- irritation risk
Cream:
- MODERATE potency
- Some hydration (not as good as ointments)
- HIGH sensitization risk
- LOW irritation risk
93
Where can a cream be used?
virtually all body sites
94
Gels:
- Potency
- Hydration
- sensitization risk
- irritation risk
Gels
- HIGH potency
- Gels are DRYING
- SIGNIFICANT sensitization risk
- -HIGH irritation risk
95
Where can gels be used?
oral mucosal surfaces, scalp
| Do not use in fissures, erosions, macerated regions
96
Lotion/solutions
- Potency
- Hydration
- Sensitization risk
- irritation risk
Lotion/solution:
- LOW potency
- VARIABLE drying
- SIGNIFICANT sensitization risk
- MODERATE irritation risk
97
Where can lotion/solution be used?
Can be used in scalp, intertriginous areas.
| Do not use in fissures/erosions
98
What is a foam?
Pressurized collection of gas bubbles in liquid film matrix. Stable at RT, melts at 37 degrees (volatile). Components evaporate and leave supersaturated active ingredient. Stain free, quick drying, no residue
99
Foam:
| -Potency
Foam:
| -STRONG potency
100
Where can foam be used?
Can be used in hair bearing areas. Avoid fissures or erosions
101
1 gram of cream covers:
10cm X 10cm
102
How much further does 1 gram of ointment spread than 1 gram of cream
1 gram of ointment spreads 10% further than 1gram of cream
103
How many topical grams are needed to cover a man's entire body?
20g
104
FTUs for 1 hand, both sides
A single hand, both sides requires 1 FTU
105
Is topical steroid class I or class VII more potent?
```
Class I is the most potent class
Class VII is the least potent class
```
106
Hydrocortizone 2.5%
cream or ointment, class VII used to treat mild eczema, inflammatory dermatoses on face, intertriginous areas, groin
107
Triamcinolone Acetonide 0.1%
cream or ointment. Class IV used in moderate spongiotic dermatoses:
eczematous dermatitis, atopic dermatitis, allergic contact dermatitis, bug bytes, drug reactions
Use on TRUNK or EXTREMITIES
Long term can't use on face, intertriginous, groin
108
Clobetasol Propionate 0.05%
```
Cream or ointment, class I used in acute eruptions needing a quick fix like contact dermatitis, acute drug eruptions
Can't use on face, intertrigious areas, groin
* long term adverse effects possible
```
109
Adverse local effects of topical steroids
Skin atrophy, generally from long term use, can cause shiny, thick skin, telangiectasia, stria. Baseline skin is more susceptible, as are intertriginous areas
110
Adverse systemic effects of topical steroids
Happens with longterm use of potent/superpotent
-adrenal suppression
-Cushing's
Growth retardation in kids
111
What's the max dose of a class I steroid every week?
50g/wk
112
Mechanisms of Penetration of Topical Medication through Stratum Corneum
passive diffusion
channels or pores
through appendageal structures
113
What is a gel?
Semisolid emulsion in alcohol base
114
What are Lotions/Solutions?
Powder in water (some oil in water)
115
Which vehicles contain preservatives that may increase the risk of contact allergy and sensitization?
Water-based vehicles (such as creams, lotions, and solutions)
116
Eczema is a more broad term that can encompasses what common skin condition?
Atopic dermatitis
117
Dx criteria for atopic dermatitis
Itchy skin + 3 or more of the following:
| involvement of skin creases, history of asthma or hay fever, dry skin, visible flexural eczema, onset under the age of 2
118
The etiology behind atopic dermatitis has to do with a _____ mutation
filaggrin
119
While babies commonly exhibit atopic dermatitis on the cheeks, in childhood, many kids have eczema on the ____ skin
flexural
| antecubital fossa, neck, wrists, ankles
120
What other conditions are associated with atopic dermatitis?
asthma and allergi rhinits
121
Irritant contact dermatitis
Most common kind of contact dermatitis
| non-immune reaction from direct cytotoxic effects from common irritants.
122
Allergic contact dermatitis is what kind of immunopathology?
Type IV hypersensitivity
123
How is allergic contact dermatitis diagnosed?
patch test
124
What is the ideology behind allergic contact dermatitis?
common allergens. Ex: nickel
125
Stasis dermatitis
skin change that occurs from stasis (blood pooling in the veins of LOWER LEG)
126
What is the etiology of stasis dermatitis?
lower extremity edema
127
Nummular dermatitis
"discoid eczema" commonly on legs but can appear on trunk or arms, common in men 50+
128
Seborrheic Dermatitis
Commonly occurs on SCALP, symmetrically over face including nasolabial folds, ears, chest.
Flaky, greasy scales
129
etiology of seborrheic dermatitis
overproduction of skin oil + yeast malasseria furfur
130
Describe psoriasis
hyper proliferation of epidermis with elongation of tete ridges and dilated capillary loops in dermal papillae
131
Seborrheic dermatitis id linkrf yo
neurological conditions, parkinsons, head injury
132
Psoriasis is a risk factor for what diseases?
cardiovascular disease
133
Most common location for psoriasis
extensor surfaces, may include arthritis
134
Cellulitis is characterized by
warm, tender erythematous patches or plaques. Located in dermis and subcutaneous tissue
135
The most common vascular tumor in adults
cherry hemagiomas, not associated with any underlying disease. Primarily truncal
136
Treatment for cherry hemangiomas
Superficial electrodesiccation
| best for small lesions
137
An infantile hemangioma is...
The most common soft tissue tumor of infancy
Benign endothelial cell neoplasm
Rapid proliferation in the first 1-3 months of life
Spontaneous involution over years
138
Port Wine Stain
Vascular malformation
Present at birth
Persists into adulthood
No gender or gestational predilection
139
Somatic mutation in port wine stains
GNAQ
140
Klippel-Trenaunay syndrome
Overgowth of an extremity covered by alorge port wine stain
| Varicose veins, venous stasis, edema, ulceration
141
Sturge Weber Syndrome
Port wine stain + ocular and neurologic abnormalities including glaucoma, seizures and developmental delay)
142
Why treat a port wine stain?
Persist into adulthood
Get worse with time
Dark purple, nodular, bleeding blebs
143
Nevus Sebaceus
-papillomatous yellow-orange linear plaque on face or scalp
Scalp Lesions associated with alopecia
Rapid growth occurs at puberty
144
Somatic mutations seen in nevus sebaceous
Somatic mutations in HRAS and KRAS
145
Complication of nevus sebaceous
Epidemal nevus syndrome (neurologic abnormalities)
| Epithelial neoplasms occur in 10-30% (Basal cell carcinoma, syringocystadenoma papilliferum)
146
Sebaceous Hyperplasia
Common benign tumor of oil gland
Increasing freq. after middle age
face>trunk>extremities
1-6 mm yellowish-white papule (globules) with central dell
147
Acrochordon
"skin tag" not treated unless causing irritation, then snip
148
Dermatofibroma
Round to oval firm nodule- depressed or dome-shaped
Several mm to 1 cm, rarely larger
Color- skin-colored to tan to brown, rarely red, blue
Surface may demonstrate scale
149
A keloid is a type of scar, which depending on its maturity, is composed of mainly either type ___ (early) or type___ (late) collagen.
III (early)
| I (late)
150
Seborrheic Keratosis
Benign tumor of the hair follicle
Exophytic papule- “stuck-on appearance
moisturize with a-hydroxy acids, lactic acid
cryosurgery
151
Leser-Trélat
Rapid increase in size or number of seborrheic keratosis
| Associated with internal malignancies, especially adenocarcinoma of the stomach (60%)
152
Nevocellular Nevi
Moles that can be an:
Intradermal nevus
Junctional nevus
Compound nevus
153
Appropriate treatment for nevocellular nevi
shave biopsy, punch biopsy, excision biopsy
| NOT electrodessication, cryotherapy, dermabrasion, laser
154
Blue Nevus
dermal proliferation of melanocytes that produce abundant melanin
Blue color- optical effect where longer wavelengths are absorbed and shorter wavelengths are reflected back (Tyndall effect)
155
Congenital nevi are common in newborns, they look like large birthmarks.
.
156
Risks associated with large congenital nevi
malignant melanoma
| Risk 1% per year in large congenital nevi (>40 cm diameter)
157
Dysplastic Nevi
Round to oval to irregular
color- tans, brown, black, reds
Margins- often indistinct (fuzzy), pigment bleeds into surrounding skin, irregular margins
Size- no limi
158
Clinical importance of dysplastic nevi
Melanomas are contiguous with dysplastic nevi
| 6.6%-70.3% in ten studies
159
FAMM Syndrome criteria
The occurrence of malignant melanoma in 1 or more first- or second-degree relatives
The presence of numerous (often >50) melanocytic nevi, some of which are clinically atypical
Many of the associated nevi showing certain histologic features
160
Germline mutations in 3 genes have been linked to a subset of FAMM syndromes:
CDK2NA
CDK4
CMM1
161
NMSC risk factors
fair skinned
areas with higher UV exposure
(UV radiation is the most common cause of BCC)
ionizing radiation, arsenic or polycyclic hydrocarbon exposure
162
Most common malignancy in the US
Basal cell carcinoma. Rarely fatal, but can be disfiguring
163
The majority of BCCs have a loss of function of the ____Gene which normally blocks the smoothened (SMO) transmembrane protein
PTCH1
164
What can be sued to treat advanced BCC?
Vismodegib, an inhibitor of smoothened
165
Actinic Keratosis
most common precancer- 58 million Americans
65% of all SCC and 36 percent of BCCs arise from AKs
166
Treatment for actinic keratosis
```
Cryosurgery
Liquid nitrogen (boiling point of -196 C)
Topical 5-fluoruracil
Topical Imiquimod
Topical Diclofenac
Photodynamic therapy
Sun protection
```
167
___ is the second most common cutaneous malignancy
Squamous cell carcinoma
168
What special group is prone to getting SCCs?
immunosuppressed pts, especially organ transplant pts
169
Risk factors for SCC
UV damage, thermal injury, radiation, HPV, burn scars (Marjolin’s ulcer) and chronic injury (i.e. EB)
170
Subtypes of SCC
SCC in situ (Bowen’s disease)
Keratoacanthoma
Invasive SCC
171
Keratoacanthoma
A type of SCC
primarily sun-exposed skin
Rapid growth over 6-8 weeks
Size- 1-3 cm
Crateriform endophytic and exophytic nodule with central keratin plug
Complications- deep invasion without regression in 10-20%
172
Can SCC metastasize?
Metastasis occurs infrequently, but is more common in SCC of the lip (10-30%)
173
Skin cancer and transplant patients
SCC = 65 fold risk
BCC = 10 fold risk
Melanoma = 3.4 fold risk
Kaposi’s sarcoma = 84 fold risk
174
Ratios of SCC:BCC in normal and transplant patients
Non-transplant pts SCC:BCC = 1:4
Transplant pts SCC:BCC = 4:1
Incidence of skin cancer increases with number of years post-transplant:
175
Non-melanoma Skin Cancer TREATMENT
```
Topical 5-fluoruracil
Topical Imiquimod
Cryosurgery
Electrodessication and Curettage
Excision
Mohs micrographic surgery
Radiation
```
176
ABCD guidelines for melanoma
```
A = Asymmetry
B = Border irregularity
C = Color variation
D = Diameter greater than 6 mm
E = Evolution (or change)
+ "ugly ducking" rule
```
177
What mutation is commonly associated with melanoma?
BRAF
178
What drug can be used for melanoma patients with BRAF mutations?
Vemurafenib, a BRAF inhibitor
179
Common race and sex specific locations for melanoma
Blacks- acral and mucosa
Men- back
Women- legs (torso in females age 15-29, perhaps due to tanning)
180
The breslow depth measures...
the depth of the melanoma in mm
181
Other mutations common in melanoma
- BRAF 50%
- NRAS 20%
- Kit 2%
- GNAQ 2%
182
Windows protect against ___, but do not filter ___ and ____ of the sun's UV rays pass through clouds on a cloudy day.
Sand reflects __% and snow reflects __% of the sun’s UV rays.
```
UVB
UVA
80%
______
25%, 80%
```
183
Sunscreen should be applied to dry skin ______minutes before going outdoors.
___ ounce of sunscreen is enough to cover the exposed areas of the body.
Sunscreen should be reapplied at least every __ hours or after swimming or sweating heavily.
15-30
1, enough to fill a shot glass
2
184
UVR Effects on the Skin
- Damage to DNA, RNA, lipids, proteins
- Pro-inflammatory effects
- Immunosuppressive effects
- Induction of innate defenses
- Induction of apoptosis
- Vitamin D synthesis
185
How does UVR induces the synthesis of cholecalciferol (VitD3) and ergocalciferol (VitD2)?
non-enzymatically
186
DNA damage induced by UVR
Thymine dimer : UVB
- Pyrimidine-6-4 pyrimidone: UVB
- Hydroxyguanosine (UVA and singlet oxygen)
187
Primary and secondary cytokines released as a result of UVR
Primary Cytokines: IL-1a, TNF-a
-Secondary cytokines:
IL-6,IL-8,IL-10, GM-CSF
188
UVR Induces Both ____ and ____
Inflammation
| Immunosuppression
189
How does UVR induce immunosuppression?
-decrease in Langerhans Cells
-induction of inhibitory cytokine network:
-Tolerance induced by Suppressor cells
Treg (CD4+CD25+)
NKT cells
190
UVR Immunosuppression Cascade
UVR Induces keratinocyte release of PAF and Cis-UCA> activates mast/B cells>IL-10 production
- PAF induces PGE2 > activates B cells >IL10
- IL-10 blocks IL-12 production by DC
- T cells cannot be activated to form cytotoxic cells, but NKT and Treg induce tolerance
191
IS UVR inhibited by high melanin content?
Not inhibited by high melanin content
| It Potentiates induction of NMSC
192
Example of genetic condition with DNA repair mechanism mutation
Xeroderma Pigmentosum is a family of diseases in which genetic defects in DNA repair lead to premature aging of the skin and fatal induction of UVR-induced skin cancers
193
DNA Repair Enzymes
Excision of mutated strand of DNA
UVR ABC nuclease
Repair replication
DNA Polymerase
Rejoining
DNA Ligase
194
Defenses against Reactive Oxygen in the Epidermis
- Peroxidases and catalases
- Superoxide dysmutase
- Glutathione reductase
- Thioredoxin reductase
195
Rate limiting step in melanin production
Tyrosinase
196
What explains 25-38% 0f European/African differences in pigmentation?
SLC24A5, a K-dependent Na/Ca ion exchanger
197
In terms of pigmentation, Potential differences in signalling pathways that control MITF
MSH, WNT, SCF/Kit
198
Viral characteristics of HPV
Non-enveloped double-stranded DNA virus
| MANY, many types
199
HPV lesions are named
Verruca_______
200
What can be given if herpes are acyclovir resistant?
Foscarnet
201
Potential complication of streptococcal impetigo
Up to 5% of streptococcal impetigo associated with acute post-streptococcal glomerulonephritis
202
Who is at increased risk for cellulitis?
```
– Very young
– Elderly
– Immunocompromised
– Intravenous drug users
– Patients with chronic ulcers
```
203
Two most common organisms causing cellulitis
strep and staph
204
Erysipelas
cellulits on the face
| "Cliff drop border"
205
Staphylococcal cellulitis can exhibit lymphatic _____
streaking
206
syphilis is caused by
Treponema pallidum
• Spirochete- 6-14 spirals
• Never cultured
207
Primary syphilis characteristics
chancre-ulcer full of spirocetes, goes away in a few weeks, characteristically PAINLESS!!! But lymphadenopathy is present
208
Secondary syphilis can be latent for
1-2 years
209
tertiary syphilis is characterized by
neuropathy
210
Rash + Lymphadenopathy =
think syphilis
211
Types of secondary skin lesions (4-10 weeks after chancre)
```
– Non-pruritic papulosquamous lesions – Condylomata lata
– Nonscarring “moth-eaten” alopecia
– Split papules at oral commissures
– Annular lesions on face
– Oral lesions
```
212
What do the dermatophytes eat and where are their infestations common?
they eat keratin, they live int he skin, hair, nails (not very deep)
213
annular plaques with raised border and central clearing outward are often called "ringworm" but they are really:
Diagnosis?
tinea corporis,
| DDx: KOH prep from leading edge
214
Increased candidiasis is seen in the following conditions:
– Diabetes mellitus
– Occlusion
– Corticosteroid use
– Broad-spectrum antibiotics
215
What does candida eat?
glucose or serum
216
Malassezia furfur like to eat
follicular lipids.
asymptomatic, tan- colored subtly scaly macule or patch
• Clinical variants
– Hypopigmented variant – Folliculitis
217
Scabies distribution
symmetric- interdigital web space, flexural wrist, waist, axillae, genitalia and breast (soft skin distribution)
218
Symptoms of scabies
Symptoms- pruritus (nocturnal accentuation)
– Erythematous papules
– Erythematous burrows
– Nodular lesions on genitalia
219
DDX of scabies
wet mineral oil prep
