Rheumatology and Dermatology Flashcards
1
Q
Nonepithelial/Nonjunctional Adhesion Mechanisms
A
- Cadherins
- ICAMs
- Integrins
- Selectins
2
Q
Hemidesmosome, cadherin, integrin, ICAM-l. Which joins only cells of the same type and does not attach cells to the basement membrane?
A
Cadherins
3
Q
Fibroblasts are involved in which tissues?
A
- Stimulated by tissue damage
- Involved in Collagen
- Glycosaminoglycans
- Reticular and elastic fibers
- Glycoproteins
4
Q
Melanocytes
A
- Melanin-producing cells
- Located in the stratum basale (bottom layer) of the epidermis
- Responsible for skin color
5
Q
Energy Exchange That Takes Place at the Skin
A
- UV light is used to generate vitamin D
- Melanocytes displace UV light as heat
- Bilirubin is converted
- Dendritic cells process antigens
- Mechanical energy is converted to electrical energy by nerve endings
6
Q
Macule
A
Flat discoloration < 1cm (ie Tinea versicolor)
7
Q
Patch
A
Macule (flat discoloration) > 1cm
8
Q
Papule
A
- Elevated skin lesion < 1 cm
- example: Acne vulgaris
9
Q
Plaque
A
- Papule> 1 cm
- example: Psoriasis
10
Q
Vesicle
A
- Small fluid-containing blister
- example: Chickenpox
11
Q
Wheal
A
- Transient vesicle
- example: Hives
12
Q
Bulla
A
- Large fluid-containing blister
- Example: Bullous pemphigoid
13
Q
Keloid
A
- Irregular, raised lesion resulting from scar tissue
- example: T pertenue (yaws)
- Follows trauma to skin, especially in African-Americans
- Usually upper chest
14
Q
Pustule
A
Blister containing pus
15
Q
Crust
A
- Dried exudates from a vesicle, bulla, or pustule
- Example: Impetigo
16
Q
Hyperkeratosis
A
- ↑ thickness of stratum corneum
- Psoriasis
17
Q
Parakeratosis
A
- Hyperkeratosis with retention of nuclei in stratum corneum
- Psoriasis
18
Q
Acantholysis
A
- Separation of epidermal cells
- Pemphigus vulgaris
19
Q
**Acanthosis **
A
Epidermal hyperplasia (↑ spinosum)
20
Q
Dermatitis
A
Inflammation of the skin
21
Q
Verrucae
A
- Warts
- Soft, tan-colored, cauliflower-like lesions.
- Epidermal hyperplasia, hyperkeratosis,koilocytosis.
- Verruca vulgaris on hands;
- Condyloma acuminatum on genitals (caused by HPV 6 and 11)
22
Q
Nevocellular nevus
A
- Common mole
- Benign
23
Q
Urticaria
A
- Intensely pruritic wheals that form after mast cell degranulation
24
Q
Ephelis
A
- Freckle
- Normal number of melanocytes
- ↑melanin pigment
25
Q
Atopic dermatitis (eczema)
A
- Pruritic eruption, commonly on skin flexures
- Often associated with other atopic diseases (asthma, allergic rhinitis)
26
Q
Allergic contact dermatitis
A
- Type IV hypersensitivity reaction that follows exposure to allergen
- Lesions occur at site of contact
27
Q
Atopic dermatitis (eczema) Treatment
A
- Switching to a moisturizing soap (Dove, Aveeno) and adding an OTC emollient may be all that is needed for maintenance and mild cases;
- Calcineurin inhibitors: tacrolimus (Protopic) or pimecrolimus (Elidel);
- Topical Steroids
- Antibiotics for open lesions (cover Staph. aureus and Strep. spp.);
- Antihistamines
- Leukotriene inhibitors (Montelukast) — theoretical efficacy supported by weak studies;
- UV light therapy
- Systemic steroids (1-2mg/kg/d in children then taper) only in severe cases and only for short duration;
- For very severe cases, consider methotrexate, cyclosporin, azathioprine
28
Q
Psoriasis
A
- Papules aiid plaques with silvery scaling, especially on knees and elbows
- Acanthosis with parakeratotic scaling (nuclei still in stratum corneum)
- ↑ stratum spinosum, ↓stratum granulosum
- Auspitz sign (bleeding spots when scales are scraped off)
- Can be associated with nail pitting and psoriatic arthritis
29
Q
Acne Pathophysiology and Treatment
A
- Hyperkeratosis - Isotretinoin (Vitamin A derivatives)
- Sebum overproduction - Estrogen, Spirinolactone
- Propionibacterium acnes proliferation - Topical - Benzoyl Peroxide, Antibiotics - Erythromycin, tetracycline, doxycycline, clyndamycin
- Inflammation - Inject with steroids
30
Q
A pregnant patient comes to the clinic complaining of new dark pigmentation on her face. What is the most likely diagnosis?
A
Melasma
31
Q
What are some of the hallmark features of necrotizing fasciitis? What organism causes this infection?
A
- Rapidly spreading cellulitis
- Tenderness beyond red border
- Strep pyogenes (GAS)
32
Q
What organism causes painless white patches on the tongue that cannot be scraped off?
A
EBV - oral hairy leukoplakia
33
Q
What is a lesion of excessive collagen deposition especially around the face ears, neck or upper chest called?
A
Keloid
34
Q
What organism is responsible for acne vulgaris?
A
Propionibacterium acnes
35
Q
Seborrheic keratosis
A
- **Flat, greasy, pigmented squamous epithelial proliferation with keratin-filled cysts (horn cysts) **
- Looks “pasted on”
- Lesions occur on head, trunk, and extremities
- Common benign neoplasm of older persons
- Sign of Leser-Trélat - sudden appearance of multiple seborrheic keratoses indicating an underlying malignancy (e.g., CI, lymphoid).
- Melanoma part of DDx
36
Q
Impetigo
A
- Very superficial skin infection
- Usually from S. aureus or S. pyogenes
- Highly contagious
- Honey-colored crusting
37
Q
Cellulitis
A
- Acute, painful spreading infection of dermis and subcutaneous tissues.
- Usually from S. pyogenes or S. aureus.
38
Q
Necrotizing fasciitis
A
- Deeper tissue injury, usually from anaerobic bacteria and S. pyogenes
- Results in crepitus from methane and CO2 production
- “Flesh- eating bacteria”
39
Q
Staphylococcal scaled skin syndrome (SSSS)
A
- Exotoxin destroys keratinocyte attachments in the stratum granulosum only
- Characterized by fever and generalized erythematous rash with sloughing of the upper layers of the epidermis.
- Seen innewborns and children
40
Q
Hairy leukoplakia
A
- White, painless plaques on the tongue that cannot be scraped off.
- EBV mediated.
- Occurs in HIV positive patients.
41
Q
Blistering skin disordes
A
- Pemphigus vulgaris - IgG against desomosomes, Acantholysis - intraepidermal bullae causing flaccid blister involving skin and oral mucosa, Positive Nikolsky
- Bullous pemphiogoid - Autoimmune disorder IgG against hemidesomsomes, antibodies are “bullow” the epiidermis, Spares oral mucosa, Negative Nikolsky
- Dermatitis herpetiformis - pruritic papules and vesicles deposits of IgA at tip of dermal papillae - celiac disease
- Erythema multiforme - Infections (M. pneumoniae, HSV), drugs, cancer, autoimmune, macules, papules, vesicles, target lesions
- Stevens-Johnson syndrome - Fever, bulla and necrosis, sloughing of skin, Drugs - Seizure meds, sulfa, penicillins, allopurinol.
- TEN worse form >30% skin sloughing/necrosis
42
Q
Lichen Planus
A
- Pruritic
- Purple
- Polygonal
- Papules
- Sawtooth infiltrate of lymphocytes at the dermal-epidermal junction
- Treat w/ 5-FU
43
Q
Actinic keratosis
A
- Premalignant lesions caused by sun exposure
- Small, rough, erythematous or brownish papules
- “Cutaneous horn”
- Risk of carcionoma proportional to epithelial dysplasia
44
Q
Acanthosis nigricans
A
- Hyperplasia of stratum spinosum
- Associated with hyperinsulinemia (Cushing’s disease, diabetes)
- Visceral malignancy
45
Q
Erythema nodosum
A
- Inflammatory lesions of subcutaneous fat
- Usually on anterior shins
- Associated with coccidioidomycosis, histoplasmosis, TB, leprosy, streptococcal infections, sarcoidosis
46
Q
Pityriasis rosea
A
- “Herald patch” (2-10cm oval read patch) Followed days later by “Christmas tree” distribution
- Multiple papular eruptions
- Remits spontaneously
- Strawberry and cherry hemangiomas also possible
47
Q
Most common skin cancers
A
- Basal cell carcioma
- Sqamous cell carcinoma
- Melanoma
48
Q
Order of metastatic risk in skin cancer
A
- Melanoma
- Squamous cell carcinoma
- Basal cell carcinoma
49
Q
Squamous cell carcinoma
A
- Very common
- UV sunlight and Arsenic
- Commonly appear on hands and face, lower lip
- Rarely metastasize
- Ulcerative red lesion
- Associated with chronic draining sinuses
- Histo: Keratin “pearls”
- Actinic keratosis is precursor to SCC
- Keratocanthoma - variant that grows rapidly (4-6 weeks) regresses spontaneously (4-8 weeks)
50
Q
Basal Cell Carcinoma
A
- Sun exposed areas
- Upper lip
- Locally invasive almost never matastasizes
- Rolled edges with central ulceration
- Pearly papules commonly with telangiectasias
- Histo: peripheral “Palisading” nuclei
51
Q
Melanoma
A
- Common tumor with significant risk for metastasis
- S-100 tumor marker
- Sunlight exposure - fair skin higher risk
- $ Depth correlates with risk of metastasis
- Dysplastic nevus (atypical mole) is precursor
- **$ ABCDs and Hx of change - **
- Asymmetry
- Border irregularity
- Color variation
- Diameter > 6 mm
