Dermatology Flashcards
Describe excoriation.
Macroscopic
Traumatic lesions breaking the epidermis, causing linear area (scratches)
Define lichenification.
Macroscopic
Thickened, red, rough skin; excessive scratching/rubbing
Define macule and patch.
Macroscopic
Circumscribed, FLAT lesion distinguished by surrounding skin color
Macule < 5 mm < Patch
Define onycholysis.
Macroscopic
Separation of nail plate from nail bed.
Define papule and nodule.
Macroscopic
Elevated, DOME-SHAPED lesion.
Papules < 5 mm < Nodule
Define plaque.
Macroscopic
Elevated, FLAT-TOPPED lesion
Define pustule.
Macroscopic
Discrete, PUS-FILLED, raised lesion.
Define scale.
Macroscopic
Dry, horny, PLATE-LIKE excrescence; imperfect cornification.
Define vesicle and bulla.
Macroscopic
Fluid-filled, raised lesion.
Vesicle < 5 mm < Bulla
Define wheal.
Macroscopic
Itchy, transient, elevated lesion with variable blanching and erythema formed from dermal edema.
Define acanthosis.
Microscopic
Diffuse epidermal hyperplasia. (Psoriasis)
Define dyskeratosis.
Microscopic
Abnormal, premature keratinization within cells below the s. granulosum.
Define erosion.
Microscopic
Discontinuity of skin showing incomplete loss of epidermis.
Define exocytosis.
Microscopic
Infiltration of epidermis by inflammatory cells.
Define hydropic swelling (ballooning).
Microscopic
Intracellular edema of keratinocytes, seen in viral infections.
Define hypergranulosis.
Microscopic
Hyperplasia of s. granulosum; d/t intense rubbing
Define hyperkeratosis.
Microscopic
Thickening of the s. corneum; qualitative abnormality of keratin.
Define lentinginous.
Microscopic
Linear pattern of melanocyte proliferation w/i epidermal basal cell layer.
Define papillomatosis.
Microscopic
Surface elevation caused by hyperplasia and enlargement of contiguous dermal papillae.
Define parakeratosis.
Microscopic
Keratinization with retained nuclei in s. corneum.
Define spongiosis.
Microscopic
INTERcellular edema of the epidermis.
Define ulceration.
Discontinuity of skin showing complete loss of epidermis, reveals dermis and subcutis
Define vacuolization.
Formation of vacuoles within or adjacent cells; basal cell-basement membrane zone area
What is the most common type of nevi and how the presence of nevi is correlated with potential increased risk of melanoma?
Most common:
Acquired melanocytic nevi (junctional, compound, intradermal)
Congenital and dysplastic nevi carry increased risk of melanoma.
What are the genetic and causative agents of melanoma?
Linked to mutations caused by UV radiation exposure to sunlight. Can be inherited as autosomal dominant.
What are the potential precursor to melanoma?
Dysplastic nevi can progress to melanoma but melanoma can also arise spontaneously.
Describe the range of morphologic findings of melanoma.
Striking variations in color; borders are notched/irregular.
What are the ABCDE’s of melanoma?
Asymmetry. Border, irregular. Color, variegated Diameter, increasing. Evolving
Describe epidemiology, locations and clinical findings of seborrheic keratoses.
Epidemiology - middle-aged adults; spontaneous
Location: trunk, head, neck, extremities
Clinical findings: round, flat coin-like waxy plaque; tan to dark brown; velvety
Describe appearance of acanthosis nigricans.
Thickened, hyperpigmented skin with “velvet-like” texture usually in flexural areas.
What common conditions are associated with acanthosis nigricans?
Diabetes mellitus, obesity, GI adenocarcinoma.
What is the etiologic agent or inciting event in the development of actinic keratoses?
Sun damage!
What are the risks and incidences of malignant transformation of actinic keratoses?
Risk of progression to small cell carcinoma. True risk of progression is unknown.
What are the common clinical features of actinic keratoses?
< 1 cm.
Tan-brown, red, rough, sandpaper consistency.
Identify the causative agent(s) and/or exposure(s) of squamous cell carcinoma.
Cumulative UV damage from sunlight, chronic ulcers, HPV 5 and 8, tobacco
What is the risk of squamous cell carcinoma metastasis and the clinical morphologic features of the lesion?
Risk - very low (~5%)
Features:
In situ - sharply defined, red, scaling plaques
Advanced = nodular, hyperkeratotic scale, may ulcerate
Identify the causative agent(s) and/or exposure(s) of basal cell carcinoma.
Sun exposure; immunosuppression, disorders in DNA repair.
What is the risk of basal cell carcinoma metastasis and the clinical morphologic features of the lesion?
Risk - very, very low
Features: pearly papules with telangiectasias, may resemble melanocytic nevi
What is urticaria, its characteristics, and its underlying mechanism of injury?
Hives; small, pruritic edematous plaque (wheal).
Mast cell degranulation with resulting vascular permeability, IgE mediated.
Define angioedema.
Edema extending to the deeper dermis and subcutaneous layers.
List the 5 categories of eczematous dermatitis.
- Allergic contact
- Atopic
- Drug-related
- Photoeczematous
- Primary Irritant
What is the pathogenesis and gross morphologic change of eczematous dermatitis?
Pathogenesis: T-cell mediated Type IV hypersentivity
Morphology: pruritic, red, paulovesicular, oozing, crusted lesions. develop reactive acanthosis and hyperkeratosis producing scales
What are the 4 main general categories of conditions associated with erythema multiforme?
- Infections
- Drug exposure
- Cancer
- Collagen vascular disease
What is the pathogenesis of erythema multiforme?
Keratinocyte injury mediated by skin-homing CD8+CTLs.
What are the clinical findings of erythema multiforme?
Diverse lesions; macules, papules, vesicles, targetoid lesions
What are the clinical findings of Stevens-Johnson Syndrome?
Fever and lesions of lips/oral mucosa, conjunctiva, urethra, genitals. Loss of skin integrity and infections leading to life-threatening sepsis
What are the clinical findings of toxic epidermal necrolysis?
Diffuse necrosis and sloughing of cutaneous and mucosal epithelial surfaces; similar to patients with extensive burns
Define psoriasis and the correlating HLA genes.
Chronic inflammatory dermatosis; HLA-C positivity shows strong correlation.
What are the common anatomical sites affected by psoriasis? What are the gross appearances?
Sites: skin of elbows, knees, scalp, lumbosacral areas, glans penis, pitting in nail bed.
Appearance: well demarcated, pink to salmon-colored plaque covered by silver-white scale
Psoriasis is a common cause of…
Inflammatory arthritis
Describe the characteristic locations and lesions of seborrheic dermatitis.
Location: high density sebaceous glands - scalp, forehead, external auditory canal, nasolabial folds, presternal area
Lesions: macules and papules on erythematous-yellow greasy base; scaling and crusting
What are the 6 “P”s of lichen planus?
- Pruritic
- Purple
- Polygonal
- Planar
- Papules
- Plaques
What are the common clinical features of lichen planus?
Itchy, flat-topped papules with white dots/lines (Wickham striae); symmetrically distributed; extremities, wrists, elbows, glans penis
Oral lesions - white, reticulated, netlike areas
Describe the “typical” patient with pemphigus.
40s - 60s
Men, women equally affected
Describe the lesions associated with pemphigus vulgaris.
Superficial vesicles and bullae that rupture easily leaving shallow erosions covered with dried serum and crust.
Describe the findings of bullous pemphigoid.
Tense bullae fille with clear fluid; erythematous; < usually 2 cm in diameter, does not rupture easily, heal w/o scarring
Describe the “typical” patient with acne vulgaris.
Mid to late teens; boys > girls
What situations may induce or exacerbate acne vulgaris?
Drugs, occupational exposures, occlusion of sebaceous glands
What are the clinical findings of open and closed comedones?
Open: small follicular papules containing black keratin plug (blackheads)
Closed: follicular papules without visible central plug (whiteheads)
Describe a “typical” patient with rosacea.
Middle age and up, female > male
What are the four stages of rosacea disease process?
- Flushing episodes
- Persistent ertyema and telangiectasia
- Pustules and papules
- Rhinophyma, thickening of nasal skin w/ erythematous papules and prominent follicles.
Define panniculitis.
Inflammatory reaction in the subcutaneous adipose tissue affecting the fat lobules and/or connective tissues that separates the fat into lobules
What are the clinical signs and symptoms of erythema nodosum?
Poorly defined, tender, erythematous plaques and nodules; fever and malaise
What are the categories of clinical conditions associated with panniculitis?
Infections, drug administration, sarcoodisosis, IBS, malignant neoplasm.
What is the etiologic agent of verrucae and its route of transmission?
HPV, direct contact or autoinoculation
Describe the lesions of verruca vulgaris.
On dorsal hands, gray-white to tan, flat to convex, rough pebble-like surface
What is etiologic agent of molluscum contagiosum and its route of transmission?
Pox virus via direct contact
Describe the typical lesions and delineate where they are most commonly found.
Firm, pruritic, pink to skin-colored umbilicated papules; 0.2 - 0.4 cm.
Multiple lesions on skin, mucous membranes, trunk and anogenital areas.
