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Flashcards in Dermatopathology II Deck (36):

6 Major Histologic Categories of Inflammatory Dermatosis

1. Lichenoid Deramatitis
2. Psoriasiform Dermatitis
3. Spongiotic Dermatitis
4. Vesiculo-Bullous Dermatitis
5. Granulomatous Dermatitis
6. Vasculopathic Dermatitis


Lichenoid Dermatitis
1. What is it?
2. Histo look?
3. Types

1. inflammation of the skin
2. band of lymphocytes under skin; predominantly T lymphocytes
3. Lichen Planus
Erythema Multiforme
Lupus Erythematosus


Lichen Planus
1. What mnemonic?
2. What is present grossly
3. What else is commonly involved?
4. Histopathology

1. 6 P's: planus, pruritic, purple, polygonal, papules/plaques
2. purple papules with wickham striae (linear whiteness)
3. oral cavity
4. lichenoid lymphocytic infiltrate with epidermal hyperplasia, hypergranulosis


Erythema Multiforme
1. Gross look
2. Causes
3. Histo look

1. targetoid rash with dusky center; annular plaque
2. HSV, mycoplasa, drugs (sulfonamides, NSAIDs)
3. necrotic keratinocytes


Acute lupus erythematosis
1. What is it?
2. Associated with what?
3. Histo look?

1. systemic lupus
2. systemic symptoms/positive serology (ANA, dsDNA)
3. lichenoid dermatitis marked by basal vaculolar change;
overlying parakeratosis/scale w/w/o follicular plugging;
increased dermal mucin


1. What is it generally?
2. What two systems does it affect?
3. What does it do to each?
4. What do pts have antibodies to?
5. What do labs show?
6. Cutaneous findings

1. autoimmune disorder
2. cutaneous skin and skeletal muscle
3. 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
4. autoantibodies against Mi-2, p155 and o140
5. elevated creatine kinase
6. Gottron's papules, heliotropy rash


Discoid Lupus Erythematosus
1. Gross look
2. Histo look
3. What do most patients not have?
4. What do most patients have?

1. Scarring, plaque-like lesion
2. perifollicular lichenoid dermatitis with vacuolar interface change, mucin deposition, thickened basement membrane; loss of pigment in basal layer
3. most don't have systemic lupus
4. positive direct immunofluorescence for IgG, IgM, C3


Psoriasiform Dermatitis
1. General histo look

1. inflammation; thickened, elongated, even epidermal projections into dermis


1. Associated with what?
2. Genetic factors
3. What cells accumulate?
4. Gross look? where?
5. What do 30% have?

1. arthritis, myopathy, enteropathy, spondylitic joint disease, acquired immunodeficiency
2. 2/3 of affected have HLA-C; only 10% of HLA-C people have psoriasis
3. CD4+ and CD8+ sensitized cells accumulate in epidermis; antigen still unknown
4. well demarcated plaques with adherent silver/white scale on elbows, knees, scalp, lumbrosacral, intergluteal cleft, and glans penis
5. nail changes: yellow-brown discoloration with pitting; onycholysis


Psoriasis Histology (3 main)

1. Psoriasiform hyperplasia with parakeratotic "wafer-like" scale containing neutrophils;
Munroe microabscesses= stratum corneum
Spongiform pustules= intraepidermal
2. Thinning of suprapapillary plates with dilated papillary vessels --> Auspitz sign (bleeding when scales are scraped off)
3. Frequent loss of the granular layer and increased epidermal mitotic figures


Spongiotic Dermatitis Histology

has fluid in between keratinocytes


Allergic Contact Dermatitis
1. What is it?
2. Gross look?
3. When does it occur?
4. Histo look

1. inflammatory disorder initiated by contact with an allergen to which the person has been previously sensitized
2. erythematous papules, small vesicles, or weeping plaques which are usually pruritic
3. 12-48 hours after exposure to allergen
4. mild intracellular edema with elongation of the intercellular bridges


Vesiculo Bullous Dermatitis
1. What is it?
2. Diagnosis Technique?
3. What does diagnosis depend on? (3)

1. vesicles or bullae at any level of epidermis
2. Direct immunofluorescence
3. Anatomic level of split;
underlying mechanism responsible for split
nature of inflammatory infiltrate


Vesiculo-Bullous Dermatitis
1. What does direct immunofluorescence look for?
2. What is caused by antibodies to structural components of the epidermis? (3)
3. What are caused by other causes?

1. presence of antibodies in the epidermis in pt skin biopsy: IgG, IgA, IgM, C3
2. Bullous Pemphigoid
Pemphigus Vulgaris
Dermatitis Herpetiformis
3. Porphyria Cutanea Tarda
Epidermolysis Bullosa


Bullous Pemphigoid
1. Who gets it?
2. Gross look; where?
3. Histo look
4. What causes it?

1. older pts
2. tense bullae; inner aspects of thighs, flexor surfaces of forearms, axillae, groin, lower abdomen
3. subepidermal blister with eosinphils
4. IgG antibodies to hemidesmosomes where the antigen resides


Pemphigus Vulgaris
1. Gross look
2. Histo look
3. Where is the split?
4. What causes it?

1. superficial vesicles and bullae that rupture easily --> shallow, crusted erosions
2. acantholysis --> suprabasalar clefting AKA "tombstoning"
3. supra-basalar
4. IgG antibodies against desmogleins (desmoglein-3); looks net-like on IF


Dermatitis Herpetiformis
1. Gross look?
2. Associated with what?
3. Treatment?
4. What causes it?

1. pruritic papules/vesicles on erythematous base; pt usually itches them
2. celiac disease
3. gluten-free diet
4. IgA


Epidermolysis Bullosa
1. What causes it?
2. Where is the blister?
3. Types (3)

1. inherited defect in structural protein of the epidermis and basement membrane
2. subepidermal blister
3. Simplex (keratin)
Junctional type (blisters at lamina lucida)
Dystrophic type (scarring; beneath lamina densa; poor course)


Porphyria cutanea tarda
1. What causes it?
2. cutaneous manifestation
3. Histo

1. disturbances in porphyrin metabolism (inherited or secondary to drugs)
2. vesicles on sun exposed skin
3. subepidermal blister w/ thickening of the blood vessel of the superficial dermis


Granulomatous Dermatitis
1. Where are the granulomas?
2. 5 types

1. both superficial and deep
2. sarcoidal - no inflammation
3. tuberculoid- caseating w/ lymphocytes
4. Necrobiotic (collagenolytic) granulomas- collagen death
5. Suppurative- neutrophils and abscess formation, usually associated w/ infection
6. Foreign body


1. Gross look
2. Histo look
3. What is it common around?

1. can look like anything
2. granuloma w/o inflammation
3. common around tattoos


Vasculopathic Dermatitis
1. Histo look
2. What can it look like (gross)?

1. inflammation of vessels; neutrophils in wall of vessel, fibrin deposition
2. pinpoint petechiae
3. could form bulla or plaque
4. Uticaria
5. Pruritic edmatous plaques (wheals)


Infections of the Skin (4)

Verruca Vulgaris
Molluscum Contagiosum
Superficial Fungal (Dermatophytosis)


1. Caused by what?
2. types?

1. HPV
2. Vulgaris
3. plana (face and dorsal hands)
4 plantaris/palmaris
5. Condyloma acuminatum


Verruca Vulgaris
1. Histo look

1. hyperkeratosis
2. hypergranulosis
3. Papillomatosis
4. Koilocytes: vacuolated keratinocytes with raisin-like (dark) nuclei


Molluscum Contagiosum
1. Gross look
2. Histo look (2)
4. Who gets it and how is it spread?

1. umbilicated papules
2. crater produced by epidermal hyperplasia;
3. molluscum bodies (intracytoplasmic inclusions that push the nucleus and keratohyaline granules aside)
4. Adults- sexually transmitted
Children can also get it


Herpes Virus Infection
1. Gross look
2. 2 causes
3. Diagnosis

1. vesicular viral exanthem
2. Herpes simplex virus (HS 1 &2); varicella zoster virus (VZV)
3. Positive Tzanck or direct fluorescence antibody of the blister contents and positive viral culture


1. Symptoms of first infection
2. Symptoms of second infection
3. Which one causes oral disease?
4. Which one causes genital disease?
5. Histo look

1. none, usually asymptomatic
2. vesicle or erosions (latent infection)
3. HSV1
4. HSV2
5. 3 M's: molding, multinucleated, marginated chromatin (seen in tissue or Tzanck smear)


VZV: Primary infection
1. AKA
2. gross look
3. Transmission
4. How long is pt infectious?

1. chicken pox
2. vesicles on red base/papules/crusted erosions
3. respiratory secretions and cutaneous lesions
4. from four days before onset to until all lesions are crusted


VZV: Reactivation of infection
1. AKA
2. gross look
3. where?
4. Who commonly gets it?
5. What is Hutchinson's sign and why is it important?

1. shingles
2. focal unilateral/dermatomal distribution unless disseminated; painful/pruritic vesicle
3. on trunk
4. pts over 50 or immunocompromised
5. HZV involvement of the nose; alerts physician to possibility of ocular involvement which can result in vision impairment if not treated promptly


Bullous Impetigo
1. Cause (2)
2. What toxins cause it? What do they do?
3. Who commonly gets it?
4. Gross look
5. Treatment
6. Histo look

1. Staphylococcus; group A beta hemolytic Strep
2. exfoliative toxins A and B from Phage II Group 71 staph; attack epidermis resulting in subcorneal splitting
3. children-common around chin; pts w/ atopic dermatitis
4. flaccid blisters that collapse easily resulting in honey colored crust
5. topical, MRSA mupirocin
6. subcorneal blister with neutrophils and bacteria present


1. what is it?
2. what causes it?
3. how are they classified?

1. fungus that live on keratin
2. microsporum, trichophyton, epidermophyton
3. according to location of infection


Tinea versicolor
1. Gross look
2. What causes it?
3. Histo look

1. Hypo or hyperpigmented macules predominantly on trunk
2. Malasssezia globosa organisms
3. hyphae and yeast forms can be seen on H and E, resemble spaghetti meatballs


Tinea nigra
1. Gross look
2. What causes it?
3. where does it infect?
4. Histo look

1. tan-brown patches on palms or soles
2. Pheoanellomyces wernieckii-
3. in kornea, especially on feet; often confused for melanoma
4. pigmented hypahe on tissue and KOH prep


1. Where does intertrigo occur?
2. Where does thrush occur?
3. Where does paronychia occur?

1. skin folds
2. mouth
3. hands


1. What is Onychomycosis?
2. What should always be considered if lesion is annular?

1. dermatophyte infection of the nail
2. fungus