Derm Flashcards
Layers of the Epidermis
"Californians Like Girls in String Bikinis" Stratum Corneum (keratin) Stratum Lucidum Stratum Granulosum Stratum Spinosum (spines = desmosomes) Stratum Basale (stem cell site)
Sebaceous gland
What kind of gland?
What does it secrete?
What is it associated with?
Holocrine (cell rupture) secretion of sebum associated with hair follicle
Eccrine gland
What does it secrete?
Where are they located?
Secret sweat
Found Everywhere
Apocrine gland What does it secrete? Where are they located? When does it begin functioning? How are they different from eccrine glands sensory-wise? Why?
Secretes milky viscous fluid
Found in axillae, genitalia, and areolae
Does not become functional until puberty
Malodorous because of bacterial action
Tight Junctions
Name
Function
Composition
Zona Occludens
Prevents paracellular movement of solutes
Claudins and Occludins
Adherens Junctions Name Location What does it form? Composition Association with disease?
Zona Adherens
Below tight junctions
Forms belt connection actin cytoskeletons of adjacent cells
CADherins (Ca dependent ADhesion proteins)
Loss of E cadherin promotes metastasis
Desmosomes Name Function Composition Disease involving them?
Macula Adherens
Structural support
Desmoplakin and Keratin
Autoantibodies –> pemphigus vulgaris
Gap Junctions
Composition
Function
Connexons (channel proteins)
Permit electrical and chemical communication
Hemidesmosomes
Function
Composition
Disease involving them?
Connect keratin in basal cells to underlying basement membrane
Integrins in cell bind Laminin in BM
Autoantibodies –> Bullous Pemphigoid
SLE
Epidemiology
Presentation
Common cause of death?
90% are female 14-45. Most common and severe in blacks
Fever, Fatigue, Wt Loss, Libman-Sacks Endocarditis, Hilar adenopathy, Raynaud Phenomenon
Nephritis is common cause of death
Nephritic: DPGN, Nephrotic: Membranous
Libman-Sacks Endocarditis
Verrucous wart-like sterile vegetations on both sides of valve
Lab results in SLE
False + on Syphilis test (RPR/VDRL) due to antiphospholipid Abs which cross react with cardiolipin used in test
ANA (sensitive but not specific)
Anti dsDNA (specific, poor prognosis)
Anti Smith Ab (specific, not prognostic)
Anti Histone Ab (sensitive for drug induced lupus)
Presentation of SLE
“I’m DAMN SHARP”
Immunoglobins (dsDNA, Smith, Phospholipids)
Malar Rash
Discoid Rash, ANA, Mucositis (oropharyngeal ulcers), Neurological disorder
Serositis (pleuritis, pericarditis), Hematologic disorders, Arthritis, Renal disorders, Photosensitivity
Sarcoidosis Epidemiology Findings Labs Histo
Black females
Enlarged bilateral hilar adenopathy or reticular opacities on CXR
↑ ACE levels, ↑ Ca (elevated 1α hydroxylase mediated VitD activation in epithelioid Macs)
Noncaseating Granulomas
Sarcoidosis
Symptoms
Associated with what disease?
Treatment
“A Red BUG”
Often asymptomatic. Erythema Nodosum, Bell’s Palsey, Epithelial Granulomas containing microscopic Schaumann and Asteroid Bodies, Uveitis
Associated with Restrictive Lung disease (interstitial fibrosis)
Steroids
Scleroderma Characterization Presentation Other organ systems involved? Epidemiology Types
Excessive fibrosis and collagen deposition throughout body
Commonly sclerosis of skin manifesting as puffy and taut skin w/o wrinkles
Sclerosis of Renal, Pulmonary (most common cause of death), CV, GI systems
75% females
Diffuse vs CREST
Diffuse Scleroderma
Presentation
Progressive
Labs
Widespread skin involvement
Rapid progression with early visceral involvement
Anti Scl70 Ab (anti DNA topoisomerase I)
CREST Syndrome Name Areas involved Prognosis Labs
Calcinosis, Raynaud’s phenomenon, Esophageal dismotility (b/c of fibrous replacement of muscularis), Sclerodactyly, Telangiectasia
Limited skin involvement (Fingers and Face)
Benign clinical course
Anti Centromere Ab
Macule
Flat lesion w/ well circumscribed change in skin color
<5mm
Patch
Macule >5mm
Papule
Elevated solid skin lesion <5mm
Plaque
Papule >5mm
Vesicle
Small fluid containing blister <5mm
Bulla
Large fluid containing blister >5mm
Pustule
Vesicle containing pus
Wheal
Transient smooth papule or plaque (Hives)
Scale
Flaking off of stratum corneum
Crust
Dry exudate
Hyperkeratosis
Thickening of stratum corneum
Parakeratosis
Hyperkeratosis with retention of nuclei in stratum corneum
Acantholysis
Separation of epidermal cells
Acanthosis
Epidermal hyperplasia (↑ spinosum)
Dermatitis
Inflammation of the skin
Albinism
What is it?
Causes
Normal melanocyte # with ↓ melanin production
↓ Tyrosinase activity or failure of neural crest cell migration during development
Melasma (Chloasma)
Hyperpigmentation associated with pregnancy or OCP use
Vitiligo
irregular areas of complete depigmentation caused by ↓ in melanocytes
Verrucae What is it? Causes by Description PathoPhys If on genitals
Warts
HPV
Soft, tan colored, cauliflower-like papules
Epidermal hyperplasia, Hyperkeratosis, Koilocytosis
Condyloma Acuminatum on genitals
Melanocytic nevus
What is it?
Malignant?
Location and description?
Common mole
Benign but melanoma can arise in congenital or atypical moles
Intradermal nevi are papular. Junctional nevi are flat macules
Urticaria
What is it?
PathoPhys
Hive
Pruritic wheal that forms after mast cell degranulation
Ephelis
What is it?
Physiology
Freckle
Normal # of melanocytes with ↑ melanin pigment
Atopic Dermatitis What is it? Common location Associated with what other diseases Course
Eczema. Pruritic eruptions
Commonly on skin flexures
Associated with other atopic disease (asthma, allergic rhinitis)
Usually starts on the face during infancy and often appears in the antecubital fossae thereafter
Allergic Contact Dermatitis
Type of Rxn
Location
Type IV hypersensitivity reaction following exposure to allergen
Lesions occur at site of contact
Psoriasis What is it? Where is it? Histo Physical Exam findings Associations
Papules and Plaques with silvery scaling
Knees and Elbows
Acanthosis with parakeratotic scaling (nuclei still in stratum corneum).
↑ Stratum spinosum, ↓ Stratum granulosum
Auspitz sign (pinpoint bleeding spots from exposed dermal papillae when sclaes are scraped off)
Associated with nail pitting and psoriatic arthritis
Seborrheic Keratosis What is it? Appearance Location Malignant Age of pt?
Flat, Greasy, Pigmented Squamous Epithelial Proliferation with keratin filled cysts (horn cysts) Looks stuck on Head, trunk, extremities Benign neoplasm Older persons
Leser Trelat Sign
Sudden appearance of multiple seborrheic keratoses indicating an underlying malignancy (GI, lymphoid)
Pemphigus Vulgaris
PathoPhys
If
Presentation
IgG Abs against desmoglein 1 +/or 3 (part of desmosome)
If reveals Abs around epidermal cells in reticular or netlike pattern
Acantholysis - Intraepidermal bullae causing flaccid blister involving skin and oral mucosa. + Nikolsky Sign
Nikolsky Sign
Separating of epidermis upon manual stroking of skin
Means that the lesion is intraepidermal
Bullous Pemphigoid PathoPhys If Histo Presentation
IgG Abs against hemidesmosomes Linear If Eosinophils within tense border Affects skin but not oral mucosa - Nikolsky sign
Dermatitis Herpetiformis
What is it?
PathoPhys
Associated with what disease?
Pruritic papules, vesicles, and bullae
Deposits of IgA at tips of dermal papillae
Associated w/ celiac disease
Erythema Multiforme
What causes it
Presentation
Infections (Mycoplasma pneumoniae, HSV), Drugs (sulfa, β lactams, phenytoin), Cancer, Autoimmune
Presents with macules, papules, vesicles, target lesions (targets with multiple rings and dusky center showing multiple epithelial disruption)
Stevens-Johnson Syndrome Presentation Danger Description of lesions Caused by Severe form
Fever, Bulla, Necrosis, Sloughing off of skin
High mortality rate
Typically 2 mucus membranes are involved. Lesions may appear like targets as seen in erythema multiforme
Adverse drug reaction
More severe form is toxic epidermal necrolysis
Acanthosis Nigricans PathoPhys Description Location Diseases associated with it?
Epidermal hyperplasia causing symmetrical hyperpigmented, velvety thickening of skin
Neck and axilla
Hyperinsulinemia (diabetes, obesity, Cushing’s) and visceral cancer
Actinic Keratosis Malignant? What causes it? Description Risk of...
Premalignant lesion caused by sun exposure
Small, rough, scaley erythematous or brownish papules or plaques
Risk of squamous cell carcinoma proportional to degree of epithelial dysplasia
Erythema Nodosum
PathoPhys
Location
Associated with what disorders?
Inflammatory lesions of subcutaneous fat
Anterior shins
Sarcoidosis, Coccidioidomycosis, Histoplasmosis, TB, Streptococcal infection, Leprosy, Crohn’s Disease
Lichen Planus
Description
Histo
Associated with what other diseases?
Pruritic, Purple, Polygonal, Planar, Papules and Plaques
Sawtooth infiltrate of lymphocytes at dermal-epidermal junction
HCV
Pityriasis Rosea
Course
Description
Herald Patch followed days later by Christmas tree distribution. Self-resolving in 6-8 weeks
Multiple plaques with collarette scales
Sunburn
PathoPhys
Kind of UV light
What can in lead to?
UV irradiation causes DNA mutations inducing apoptosis of keratinocytes
UVA is dominant in tanning and photoaging
UVB is dominant in sunburn
Can lead to impetigo and skin cancers (basal cell carcinoma, squamous cell carcinoma, and melanoma)
Impetigo What is it? What causes it? Epidemiology Presentation
Very superficial skin infection
S aureus or S pyogenes
Highly contagious
Honey colored crusting
Bullous Impetigo
Bullae caused by S aureus
Cellulitis What is it? Presentation Caused by? Course
Spreading infection of dermis and subcutaneous tissues
Acute and painful
S pyogenes or S aureus
Often starts with break in skin from trauma or another infection
Necrotizing fasciitis
What is it?
What causes it?
Presentation
Deeper tissue injury
Anaerobic bacteria or S pyogenes. “Flesh eating bacteria”
Crepitus from methane and CO2 production
Bullae and purple colored skin
Staphylococcal scalded skin syndrome (SSSS)
PathoPhys
Presentation
Classic Pt?
Exotoxin destroys keratinocyte attachment in the stratum granulosum only
Fever and generalized erythematous rash with sloughing of the upper layers of the epidermis that heals completely
Newborns and children
Toxic Epidermal Necrolysis
Exotoxin destroys epidermal-dermal junction
Hairy Leukoplakia
What is it?
What causes it?
What kind of pt gets it?
White, painless, plaques on the tongue that cannot be scraped off
EBV
HIV+ pt
Basal Cell Carcinoma Frequency Location Invasion? Metastatic? Presentation Secondary presentation? Histo
Most common skin cancer
Sun exposed areas
Locally invasive but almost never metastasizes
Pink, Pearly nodules commonly w/ telangiectasias, rolled border, central crusting or ulceration
Also appears as nonhealing ulcer with infiltrating growth or a scaling plaque
Palisading nuclei
Squamous Cell Carcinoma Frequency What causes it? Location Invasion? Metastatic? Presentation Associated w/ Histo
2nd most common skin cancer
Sun exposure, immunosuppression, arsenic exposure
Face, lower lip, ears, hands
Locally invasive but may spread to lymph nodes and will rarely metastasize
Ulcerative red lesions with frequent scales
Associated with chronic draining sinuses
Keratin pearls
Keratoacanthoma
Variant of Actinic Keratosis that grows rapidly (4-6 weeks) and may regress spontaneously over months
Melanoma Metastatic? Marker? Risk factors? Presentation
Depth of tumor correlates with metastasis
S-100
Sunlight exposure. Fair skinned persons
Asymmetry, Border irregularity, Color variation, Diameter > 6mm, Evolution over time
Melanoma
Genetics
Treatment
BRAF kinase mutation. BRAF V600E is metastatic and unresectable.
Excision with appropriately wide margins. BRAF V600E: use Vemurafenib or BRAF kinase inhibitors
