Derm Review Flashcards
Fitzpatrick skin types
I- Never tans, always burns II - Tans with difficulty, usually burns III - average tanning sometimes burns IV - easily tans, rarely burns V - very easy to tan, rarely burns VI - never burns
Skin pigmentation is due to…
Type of melanin produced
Distribution of melanosomes
Dark skin (2)
melanosomes larger and distributed individually throughout the cytoplasm of the keratinocyte
Eumelanin (black to brown pigment)
Light skin (2)
melanosomes smaller and distributed in clusters above the nucleus in the keratinocyte
-Pheomelanin (yellow to red-brown pigment)
Vitiligo (3)
- Acquired depigmentation
- complete absence of melanocytes
- seen in periorifical and acral locations
Hemidesmosomes attach ______ to ______
epidermis to dermis (basal cells to basal lamina of dermal-epidermal junction)
Desmosomes attachments between _____ within _______
keratinocytes
within the stratum spinosum
Congenital disease of the hemidesmosomes
epidermolysis bullosa (EB)
Dystrophic epidermolysis bullosa (EB)
- No collagen 7
- problem with hemidesmosomes
-extensive dystrophic scarring causing deformity
Acquired problem of hemidesmosomes
Bullous Pemphigoid
-antibodies to hemidesmosomes
Epidermolysis bullosa simplex
defect in keratin 5 and 14
- generalized blisters after birth
- intraepidermal (not as severe scarring as recessive dystrophic variant)
- Occurs less as patients age
Acquired disease of the desmosomes
Pemphigus Vulgaris
Pemphigus Vulgaris
- skin lesions are flaccid bulla
- abs to desmoglein
- intraepidermal blisters
- blisters on skin and oral mucosa
______ and ________ both are due to defects in filaggrin that cause a defect in the skin barrier function
Icthyosis Vulgaris and Atopic Dermatitis
skin is always dry
Ichthyosis Vulgaris appears as
plate like scales
Papillary dermis
- upper layer
- thin collagen bundles
- interlocks with epidermal rete
- increases strength and surface area
Reticular dermis
- deeper layer
- thick collagen bundles
- visible elastic fibers
3 major constituents of the dermis and their functions
1) Collagen - forms the tensile strength
2) Elastic fibers - allow for resilience
3) Ground substance - facilitates diffusion
Acquired disorder of elastin
Solar elastosis
damaged elastic fibers from UV light
Congenital disorder of elastin
Pseudoxanthoma Elasticum
Acquired blistering disorder of DEJ
Bullous pemphigoid
Congenital blistering disorder of DEJ
Epidermolysis bullosa
What nail finding is associated with HIV and what is it caused by
proximal subungual white onychomycosis (basically white nail on the proximal half)
-caused by trichophyto rubrum
alopecia areata
autoimmune against hair follicles
Hair growth cycle
1) Anagen (growing hair)
2) Catagen (involuting hair)
3) Telogen (resting hair)
Anagen Effluvium
loss of growing hairs (e.g. chemo)
Telogen Effluvium
hairs go into resting cycle
Dermatitis is the same thing as _________
Eczema
Atopic dermatitis
located where?
Associated with what diseases?
defect where?
Due to defect in Filaggrin
Associated with asthma and allergic rhinitis
On flexor surfaces (skin folds)
Seborrheic Dermatitis
caused by?
symptom?
location?
Malassezia furfur
Dandruff (psoriasis has a thicker more silver scale)
On scalp (aka cradle cap)
Psoriasis
appearance/symptom
location
associated diseases
Silver scale, itchy
Extensor surfaces
Associated with increased risk of CV disease and arthritis
Irritant Dermatitis (e.g. intertrigo) is caused by __________
common irritants (fragrance)
Stasis Dermatitis
LE edema
On Lower legs
Allergic contact dermatitis
caused by?
what kind of hypersensitivity reaction?
how do you diagnose it?
Common allergens
Delayed Type IV Hypersensitivity Reaction
Diagnosis confirmed with patch testing
Type I hypersensitivity reactions
- anaphylactic reactions
- IgE ab to specific antigen → histamine release → vasodilation, smooth muscle contraction
EX) Urticaria and angioedema (peanut allergy, bee venom)
Type IV hypersensitivity reaction
Langerhans cells (APCs) present antigen → make memory T cells that are sensitized to locally deposited antigens
Local reaction occurs - does NOT involve antibodies
EX) Morbilliform Drug Eruptions, Allergic contact dermatiti
Impetigo is typically caused by ______ while erysipelas is usually caused by ______
staph
strep
Impetigo appearance
honey colored crust, slightly bullous, localized spot
Erysipelas appearance
spreading erythema across face, warm, tender, cliff-drop border
Tinea Versicolor
Hyper or hypopigmented patches
Typically on chest
Warm, humid environment
Yeast (Malassezia furfur)
Short hyphae and spores (spaghetti and meatballs)
Scabies
In between fingers
Infestation of the skin
Seborrheic Keratosis
“Barnacles of life”
Benign skin tumor
Clonal proliferation of keratinocytes
Intradermal Nevus
in dermis (skin colored), broad base
Junctional Nevus
just in DEJ, flat, pigmented
Compound nevus
melanocytes in dermis and DEJ
Skin Defenses against UV radiation
DNA repair
Apoptosis of Cells with DNA damage
Defenses against ROS
Melanin
Actinic Keratosis is a precursoe to _______ derived from a ________
SCC, keratinocyte
UVA causes…
dark patches, wrinkles, loose skin, premature aging, DNA damage, melanoma, non-melanoma
UVA penetrates ______ due to its ______ wavelength
Penetrates into dermis → damages collagen fibers
Longer wavelength
UVB penetrates ______ due to its ______ wavelength
Only penetrates epidermis
Shorter wavelength
UVB causes…
sunburn, eye problems, DNA damage, melanoma, non-melanoma
UVR effects on the skin (6)
Damage to DNA, RNA, lipids and proteins
Pro-inflammatory effects
Immunosuppressive effects
Induction of innate defenses
Induction of apoptosis
Vitamin D synthesis
Photodermatoses (3)
1) Lupus Erythematosus
2) Dermatomyositis
3) Mixed connective tissue disease (MCTD)
Dermatomyositis appearance and presentation
Photodistributed
Scalp, periocular and extensor skin sites
Periorbital edema, eruption on upper eyelids (heliotrope)
Samitz sign
ragged cuticles
associated with dermatomyositis
Gottron’s papules
associated with dermatomyositis
on hands, knuckles, elbows, knees, diffuse red papules
Gottron’s sign
poikiloderma over the knuckles, elbows, knees
associated with dermatomyositis
Shawl sign
associated with dermatomyositis
poikiloderma across back and shoulders
Adult onset of dermatomyositis can be associated with…
internal malignancy in patients with DM
Neurofibromatosis signs include (5)
Cafe-au-lait
Axillary freckling
Optic Glioma and Lisch nodules (eyes)
Neurofibromas
Tuberous Sclerosis
signs (3)
systemic associations?
genetic disorder
Adenoma sebaceum on the face (kinda looks like bad acne)
Hypomelanotic macules (on back)
Shagreen patch (big red bump)
Can involve heart, kidneys (renal cysts)
Kaposi’s Sarcoma is associated with _____
HIV
Pyoderma Gangrenosum
cut doesn’t heal, ulcerates
DO NOT debride, AVOID surgery - trauma induces it
Oral/topical anti-inflammatory agents preferred
Pyoderma Gangrenosum Indicative of what underlying diseases?
IBD
Arthritis
Monoclonal gammopathy
Other hematologic disorders (myelogenous leukemia, myelofibrosis)
Lichen Planus
appearance
associated disease
higher incidence of HepC
Purple, polygonal, pruritic papules
Wickham’s striae (overlying lace-like white line pattern on surface)
Acanthosis Nigricans
Velvety hyperpigmentation of intertriginous surfaces
Common in obese patients
Stimulates epidermal keratinocytes and dermal fibroblasts to proliferate → skin thickening and looks darker
Acanthosis Nigricans
associated with what diseases? (5)
Obesity, insulin insensitivity (DM)
Endocrinopathies
Drugs
Internal malignancy - IF they are losing weight
Adenocarcinoma of stomach
