study guide wk 1 Flashcards
Know the significance of desmosomes in skin pathology
hold skin together
How do melasma and Vitiligo differ?
Irregular, completely depigmented patches devoid of melanocytes vs. hyperpigmentation on the face
What is the fundamental difference between freckles and Lentigo?
freckles: Increased melanin deposition in the basal cell layer of the epidermis Normal number of melanocytes VS. lentigo: localized proliferation of
melanocytes that appear, linear hyperplasia (age spots)
What does the word Lentigo mean?
localized proliferation of melanocytes. small,brown, oval. only i basal layer
What are the characteristics of congenital birthmarks?
increased melanoma risk, appearance varied….
What is meant by the word nevus?
“nest” Benign tumor of melanocytes. junctional,
compound, and intradermal. Uniform tan to brown color
Sharp, well circumscribed borders. Stable. malignancy rare
What characteristics indicate that a nevus may be dysplastic?
larger and irregular and may have pigment variation. nevus exhibits cytological and architectural atypia. syndrome inc. melanoma risk
Which type of melanoma has the best prognosis, which types have the worse?
best: lentigo maligna melanoma (superficial)
worst:Nodular melanoma (vertical growth)
acral can be bad if not discovered (under nails, dark skinned patiets)
What is the most common type of melanoma?
Superficial spreading melanoma
In general, how is the malignant potential of melanoma assessed?
Staging is by depth of invasion (vertical
growth)
• Breslow’s thickness
• Clark’s levels
What can Acanthosis Nigricans be an indication of?
Thickened, hyperpigmented skin in the axillae and groin–> obesity, hyper-insulinemia (rarely intestinal malignancy)
What is the sign of Leser-Trelat?
Seborrheic Keratosis. Leser-Trelat (paraneoplastic
syndrome): sudden development of multiple lesions may accompany an underlying malignancy
What is the basic pathophysiology of psoriasis?
Autoimmune disorder accompanied by increased
proliferation and turnover of epidermal keratinocytes
Epidermal hyperplasia (Acanthosis)
• Patchy Hyperkeratinization
• Uniform elongation and thickening of the rete
• Thinning of the epidermis over the dermal papillae
• Munro microabscesses
What test is used in the clinic to evaluate for it?
Auspitz sign: capillary bleeding under scale
What is the basic pathophysiology of Pemphigus?
autoimmune disorder that is characterized by intraepidermal blister formation. Production of autoantibodies directed against a part of the keratinocyte DESMODOMES called desmoglein 3
results in loss of intercellular adhesions (acantholysis) and blister formation
Intraepidermal acantholysis
What test are used in the clinic to evaluate for pemphigus?
Nikolski’s sign, 3 min.
What immunoglobulin is involved in the pathogenesis of Dermatitis Herpetiformis, and what disease is the condition thought to be linked to?
Production of IgA antibodies directed against gliadin and other antigens that deposit in the tips of the dermal papillae and result in subepidermal blister formation.
Celiac sprue
What is the difference between Xerosis and Eczema (the two look similar)?
Xerosis:cause of pruritus and dry skin in the elderly that is due to decreased skin lipids
Eczema: IgE mediated. characterized by pruritus, causes a vesicular, erythematous rash. Chronic thickenedhyperkeratotic skin
What is the basis of the butterfly rash of cutaneous lupus erythematous?
epidermal atrophy with deposition of DNA-anti DNA immune complexes in the basement membrane of the
epidermis–> around nose and cheecks
Is Pityriasis Rosea a dangerous condition?
herald patch, christmas tree, maybe virally caused. NOT DANGEOUS
What is the difference between Erythema Nodosum and Erythema Multiforme?
Nodosum: raised, erythematous, painful nodules of subcutaneous adipose tissue. SHINS. idiopathic-strep
Multiforme:hypersensitivity skin reaction to infections. vesicles, bullae, and “targetoid” erythematous lesions.
Stevens Johnsons syndrome
What is the significance of actinic keratosis?
precursor of squamous cell carcinoma. Sun-induced
dysplasia of the keratinocytes. Bowen disease SCC in situ
What layers are involved with the following: BCC, SCC, Melanoma
Basal layer of keratinocytes, SCC in stratum corneum, melanoma in epidermis –> subcutaneous layer (Breslow’s thickness, Clark’s levels)
