Dermopath 1 Flashcards
(25 cards)
What are the main structural proteins in the dermis?
Collagen and elastin are the primary structural proteins that provide tensile strength and elasticity to the dermis.
What type of collagen is predominantly found in the dermis?
Type I collagen is the most abundant in the dermis, providing tensile strength, followed by Type III collagen in the papillary layer.
What is the function of fibroblasts in dermal pathology?
Fibroblasts synthesize extracellular matrix proteins like collagen and elastin and play a role in wound healing and fibrosis.
What is elastosis, and how does it manifest histologically?
Elastosis is the degeneration of elastic fibers, often due to sun damage, and appears as thickened, clumped, basophilic fibers in the dermis.
What are the common histological findings in chronic dermatitis?
Chronic dermatitis shows epidermal hyperplasia, spongiosis, lymphocytic infiltrates, and fibrosis in the dermis.
What is the primary histological feature of a keloid?
Keloids exhibit excessive collagen deposition in the dermis, forming thick bundles of collagen beyond the original wound boundary.
How does erythema nodosum present histologically?
Erythema nodosum shows panniculitis with septal inflammation, involving lymphocytes, neutrophils, and giant cells in the subcutaneous fat.
What is the characteristic finding in leukocytoclastic vasculitis?
Leukocytoclastic vasculitis presents with fibrinoid necrosis of vessel walls, neutrophilic infiltration, and nuclear dust (leukocytoclasia).
What are the key features of scleroderma in the dermis?
Scleroderma shows thickened collagen bundles, loss of adnexal structures, and hyalinized, densely packed collagen in the dermis.
How does granuloma annulare differ from necrobiosis lipoidica histologically?
Granuloma annulare shows palisading histiocytes around necrotic collagen, while necrobiosis lipoidica has thickened collagen with lipid deposits and granulomatous inflammation.
What is the primary histological difference between psoriasis and eczema?
Psoriasis shows parakeratosis and Munro microabscesses, while eczema exhibits spongiosis and lymphocytic infiltrates.
What type of blister formation is seen in dermatitis herpetiformis?
Dermatitis herpetiformis shows subepidermal blisters with neutrophilic microabscesses at the dermal papillae.
What immunofluorescence pattern is seen in pemphigus vulgaris?
Pemphigus vulgaris shows intercellular IgG and C3 deposition in a ‘chicken wire’ pattern within the epidermis.
What is the distinguishing feature of bullous pemphigoid under direct immunofluorescence?
Bullous pemphigoid shows linear IgG and C3 deposition along the basement membrane zone.
What is the clinical presentation of erythema multiforme?
Erythema multiforme presents with target lesions, often associated with infections or medications, and shows interface dermatitis histologically.
How does cutaneous lupus erythematosus differ histologically from systemic lupus?
Cutaneous lupus shows vacuolar interface dermatitis and thickened basement membrane, while systemic lupus may also involve deeper dermal vasculitis and immune complex deposition.
What role do macrophages play in granulomatous inflammation?
Macrophages phagocytose debris, present antigens to T cells, and secrete cytokines that promote granuloma formation, such as TNF-α and IL-12.
What is the hallmark finding in Sweet’s syndrome?
Sweet’s syndrome shows dense neutrophilic infiltrates in the upper dermis with associated edema and leukocytoclasia.
What is the typical histological finding in lichen simplex chronicus?
Lichen simplex chronicus shows epidermal hyperplasia, hyperkeratosis, and a thickened granular layer, reflecting chronic scratching and rubbing.
What are the histological features of nodular vasculitis?
Nodular vasculitis presents with septal panniculitis, granulomatous inflammation, and fibrosis in the subcutaneous fat.
How does necrobiosis lipoidica present histologically?
Necrobiosis lipoidica shows thickened collagen, granulomatous inflammation, and lipid-laden macrophages in the dermis.
What is the characteristic finding in pyoderma gangrenosum?
Pyoderma gangrenosum shows neutrophilic dermatosis with sterile pustules, necrosis, and ulceration.
What is the primary histological feature of sarcoidosis?
Sarcoidosis is characterized by non-caseating granulomas composed of epithelioid histiocytes and multinucleated giant cells.
What is the pathophysiological basis of panniculitis?
Panniculitis involves inflammation of subcutaneous fat and can present as septal, lobular, or mixed panniculitis based on histological patterns.
