Dermatopathology II Flashcards
1
Q
6 Major Histologic Categories of Inflammatory Dermatosis
A
- Lichenoid Deramatitis
- Psoriasiform Dermatitis
- Spongiotic Dermatitis
- Vesiculo-Bullous Dermatitis
- Granulomatous Dermatitis
- Vasculopathic Dermatitis
2
Q
Lichenoid Dermatitis
- What is it?
- Histo look?
- Types
A
- inflammation of the skin
- band of lymphocytes under skin; predominantly T lymphocytes
- Lichen Planus
Erythema Multiforme
Lupus Erythematosus
Dermatomyositis
3
Q
Lichen Planus
- What mnemonic?
- What is present grossly
- What else is commonly involved?
- Histopathology
A
- 6 P’s: planus, pruritic, purple, polygonal, papules/plaques
- purple papules with wickham striae (linear whiteness)
- oral cavity
- lichenoid lymphocytic infiltrate with epidermal hyperplasia, hypergranulosis
4
Q
Erythema Multiforme
- Gross look
- Causes
- Histo look
A
- targetoid rash with dusky center; annular plaque
- HSV, mycoplasa, drugs (sulfonamides, NSAIDs)
- necrotic keratinocytes
5
Q
Acute lupus erythematosis
- What is it?
- Associated with what?
- Histo look?
A
- systemic lupus
- systemic symptoms/positive serology (ANA, dsDNA)
- lichenoid dermatitis marked by basal vaculolar change;
overlying parakeratosis/scale w/w/o follicular plugging;
increased dermal mucin
6
Q
Dermatomyositis
- What is it generally?
- What two systems does it affect?
- What does it do to each?
- What do pts have antibodies to?
- What do labs show?
- Cutaneous findings
A
- autoimmune disorder
- cutaneous skin and skeletal muscle
- cutaneous: histo almost identical to acute lupus except frequently more epidermal atrophy
skeletal muscle: myositis: perivascular mononuclear cell infiltrate, tubuloreticular inclusion in endothelial cells with myofiber damage in a paraseptal or perifasicular pattern - autoantibodies against Mi-2, p155 and o140
- elevated creatine kinase
- Gottron’s papules, heliotropy rash
7
Q
Discoid Lupus Erythematosus
- Gross look
- Histo look
- What do most patients not have?
- What do most patients have?
A
- Scarring, plaque-like lesion
- perifollicular lichenoid dermatitis with vacuolar interface change, mucin deposition, thickened basement membrane; loss of pigment in basal layer
- most don’t have systemic lupus
- positive direct immunofluorescence for IgG, IgM, C3
8
Q
Psoriasiform Dermatitis
1. General histo look
A
- inflammation; thickened, elongated, even epidermal projections into dermis
9
Q
Psoriasis
- Associated with what?
- Genetic factors
- What cells accumulate?
- Gross look? where?
- What do 30% have?
A
- arthritis, myopathy, enteropathy, spondylitic joint disease, acquired immunodeficiency
- 2/3 of affected have HLA-C; only 10% of HLA-C people have psoriasis
- CD4+ and CD8+ sensitized cells accumulate in epidermis; antigen still unknown
- well demarcated plaques with adherent silver/white scale on elbows, knees, scalp, lumbrosacral, intergluteal cleft, and glans penis
- nail changes: yellow-brown discoloration with pitting; onycholysis
10
Q
Psoriasis Histology (3 main)
A
- Psoriasiform hyperplasia with parakeratotic “wafer-like” scale containing neutrophils;
Munroe microabscesses= stratum corneum
Spongiform pustules= intraepidermal - Thinning of suprapapillary plates with dilated papillary vessels –> Auspitz sign (bleeding when scales are scraped off)
- Frequent loss of the granular layer and increased epidermal mitotic figures
11
Q
Spongiotic Dermatitis Histology
A
has fluid in between keratinocytes
12
Q
Allergic Contact Dermatitis
- What is it?
- Gross look?
- When does it occur?
- Histo look
A
- inflammatory disorder initiated by contact with an allergen to which the person has been previously sensitized
- erythematous papules, small vesicles, or weeping plaques which are usually pruritic
- 12-48 hours after exposure to allergen
- mild intracellular edema with elongation of the intercellular bridges
13
Q
Vesiculo Bullous Dermatitis
- What is it?
- Diagnosis Technique?
- What does diagnosis depend on? (3)
A
- vesicles or bullae at any level of epidermis
- Direct immunofluorescence
- Anatomic level of split;
underlying mechanism responsible for split
nature of inflammatory infiltrate
14
Q
Vesiculo-Bullous Dermatitis
- What does direct immunofluorescence look for?
- What is caused by antibodies to structural components of the epidermis? (3)
- What are caused by other causes?
A
- presence of antibodies in the epidermis in pt skin biopsy: IgG, IgA, IgM, C3
- Bullous Pemphigoid
Pemphigus Vulgaris
Dermatitis Herpetiformis - Porphyria Cutanea Tarda
Epidermolysis Bullosa
15
Q
Bullous Pemphigoid
- Who gets it?
- Gross look; where?
- Histo look
- What causes it?
A
- older pts
- tense bullae; inner aspects of thighs, flexor surfaces of forearms, axillae, groin, lower abdomen
- subepidermal blister with eosinphils
- IgG antibodies to hemidesmosomes where the antigen resides