Sweep 1.6 Flashcards
• Macule:
flat, circumscribed area <5 mm
• Patch:
flat, circumscribed area >5mm
• Papule:
elevated lesion <5 mm
• Plaque:
elevated lesion > 5 mm
• Pustule:
discrete pus-filled lesion
• Vesicle:
fluid-filled lesion <5 mm
• Bulla:
fluid-filled lesion >5 mm
Acute Urticaria
PATHOGENESIS
• Mast cell degranulation increased dermal vascular permeability dermal edema
• Immediate Type I (IgE) hypersensitivity rxn • Inciting factor: medications (opiates, abx)
TREATMENT
• Antihistamines
Erythema Multiforme
CLINICAL FEATURES
- “targetoid” lesions
- Multiple features with macules, papules, vesicles with central pallor
- Can lead to epidermal desquamation if progresses
Chronic Inflammatory Dermatosis: PSORIASIS
Psoriasis CLINICAL FEATURES
• erythematous salmon-pink colored plaques with silvery scale
– extensor elbows, knees, scalp, gluteal cleft
– nail thickening and dystrophy
• Koebner: induce lesion by local trauma
• Auspitz sign: punctate bleeding when overlying scale is removed
Psoriasis
– ———- scale
Parakeratotic
Lichen Planus
- Pruritic
- Purple
- Polygonal
- Planar papules and plaques
- Covered in Oral Pathology
Impetigo
– Staph Aureus, can be Strep pyogenes
– Contagious, more commonly in kids, spread through direct contact
– Starts as small macule often perioral/perinasal
– Enlarges with honey-colored crust (dried serum)
– Treat with antibiotics with good Staph coverage
Acantholysis: lysis of
intercellular junctions between squamous cells
• Subcorneal (superficial epidermis at stratum granulosum): pemphigus foliaceus
• Suprabasal (above basal cell): pemphigus vulgaris
Nonacantholysis
• Subepidermal (below DEJ): bullous pemphigoid with intact intercellular junctions
Pemphigus • Type —- hypersensitivity reaction
• IgG autoantibodies bind to ———
II
desmoglein type I and type 3 intercellular desmosomal proteins
Pemphigus
– Disrupted intercellular adhesion causes ———-
blistering
Pemphigus
• DIF: intercellular IgG deposition along --------- cell membranes (fish-net)
keratinocyte
– Pemphigus vulgaris: —– deposits throughout epidermis –
IgG
Pemphigus foliaceus: IgG deposits in ——- layers of
epidermis
superficial
Actinic Keratosis/Cheilitis
- Red, rough patches on ———- (mainly head/neck, lips, dorsal hands)
- More common in ———–•
chronically sun exposed skin
fair-skinned and blond/red heads
Actinic Keratosis/Cheilitis
Histo: cytologic atypia with ——– of basal cells with overall epidermal ———
hyperplasia
thinning
Actinic Keratosis/Cheilitis
• Can rarely evolve into ———–, particularly with ——- mutation from UV DNA damage
squamous cell carcinoma
TP53
Actinic Keratosis/Cheilitis
• Treatment: ——- (liquid nitrogen), ————
cryotherapy
topical chemotherapy agents
Squamous Cell Carcinoma
forms in
basal layer
SCC mutations
TP53 mutation
• HRAS and Notch receptor mutations
SCC metastasis
- Mucosal>cutaneous
- Thickness of lesion and depth of invasion into dermis
- Size >2 cm
- Ulceration
- High risk locations such as head/neck, particularly lips, ears, around eyes
Basal Cell Carcinoma • Most common type of skin cancer
• Pearly pink, translucent papules with telangiectasias; can become nodular and ulcerate
• Superficial: multifocal growth in epidermis
• Nodular: downward invasion to dermis
– Can be locally aggressive but rarely metastasizes
Basal Cell Carcinoma
Histopathology
• Arise in ——– of epidermis
• Palisading nests of ——— cells with ——– nuclei surrounded by ———
basal layer
basaloid
hyperchromatic
fibrotic stroma
Genetic disorder: Basal Cell Nevus Syndrome (Gorlin Syndrome) with
PTCH gene mutation in Hedgehog tumor suppressor pathway
Melanocytic Nevi (Moles)
• benign neoplasm of melanocytes
• Congenital or acquired
• —– mutation as common factor in nevi
• Cellular senescence: migration of nevi from ——–– Superficial nevi: produce melanin, grow in nests
– Deeper nevi: minimal to no pigment, grow in ——– or single cells
BRAF
DEJ into dermis
cords
