Dermatopathology III

Question 1

Age range for pemphigus vulgaris:

Answer 1

30-50

Question 2

Pemphigus vulgaris:

Answer 2

IgG autoantibodies against desmogleins 1 and 3 in desmosomes in the suprabasal deep epidermis and mucosal epithelium.

Question 3

Pemphigus vulgaris blisters (2):

Answer 3

• Suprabasal split; acantholytic blisters

- Positive Nikolsky sign

Question 4

Pemphigus foliaceus:

Answer 4

Autoantibodies against Dsg1; superficial, subcorneal blisters

Question 5

Pemphigus vulgaris direct immunofluorescence pattern:

Answer 5

Net-like pattern of intracellular IgG deposits

Question 6

Bullous pemphigoid age range:

Answer 6

Elderly

Question 7

Bullous pemphigoid presents on (5):

Answer 7

• Inner aspects of thighs
• Flexor surfaces of forearms
• Axillae
• Groin
• Lower abdomen

Question 8

Bullous pemphigoid target antigens:

Answer 8

BPAg1 and BPAg2 in the hemidesmosome.

Question 9

Bullous pemphigoid blisters:

Answer 9

Subepidermal, noncantholytic blisters

Question 10

Bullous pemphigoid direct immunofluorescence:

Answer 10

Linear deposition of C3 and IgG along dermoepidermal junction

Question 11

Dermatitis Herpetiformis age range:

Answer 11

20-60

Question 12

Dermatitis Herpetiformis etiology:

Answer 12

IgA autoantibodies to transglutaminases bind to TG in gut and cross-react with reticulin in fibrils in skin.

Question 13

Dermatitis Herpetiformis associated with HLAs (3):

Answer 13

• HLA-B8
• HLA-DR
• HLA-DQ

Question 14

Dermatitis Herpetiformis lesions (4):

Answer 14

• Symmetrically grouped
• Papules and plaques progressing to vesicles and bullae
• Buttocks, elbows, knees, scapular areas
• Very pruritic

Question 15

Dermatitis Herpetiformis type of blister:

Answer 15

Subepidermal blister

Question 16

Direct immunofluorescence of Dermatitis Herpetiformis :

Answer 16

Discontinuous granular deposition of IgA in tips of dermal papillae

Question 17

Dermatitis Herpetiformis diagnosis (3):

Answer 17

• Skin biopsy
• Antiendomysial antibodies (specific for TG)
• Endoscopy: blunting of villi in small bowel

Question 18

Dermatitis Herpetiformis treatment (2):

Answer 18

• Gluten-fee diet (slow)
• Dapsone (fast)
  
  • Check G6PD level

Question 19

Porphyria cutanea tarda age range:

Answer 19

30-50

Question 20

Porphyria cutanea tarda etiology:

Answer 20

Uroporphyrinogen decarboxylase (UROD) deficiency leads to excessive accumulation of porphyrins

Question 21

Porphyria cutanea tarda cause (3):

Answer 21

• Porphyrins make skin photosensitive
• Tense subepidermal bulla on normal appearing skin in sun exposed areas
• May also get hypertrichosis on face

Question 22

Porphyria cutanea tarda diagnosis:

Answer 22

Test for increased uroporphyrin in urine

- Will fluoresce orange under woods lamp

Question 23

Acne vulgaris pathogenesis:

Answer 23

Obstruction of sebaceous follicles by sebum promotes proliferation of p. acnes.

Question 24

Acne rosacea age range:

Answer 24

30-50

Question 25

Acne rosacea:

Answer 25

Chronic inflammatory disorder that affects blood vessels and pilosebaceous units

Question 26

Acne rosacea 4 stages:

Answer 26

1. Flushing episodes 2. Persistent erythema and telangiectasias 3. Pustules and papules 4. Rhinophyma

Question 27

Panniculitis:

Answer 27

Inflammation of fat lobules or the connective tissue septa separating fat lobules

Question 28

Erythema nodosum age range:

Answer 28

20-30

Question 29

Erythema nodosum:

Answer 29

Inflammatory reaction of connective tissue septa separating fat lobules

Question 30

Erythema nodosum presents as (4):

Answer 30

- Painful, red, subcutaneous, elevated nodules - Nodules indurated and poorly circumscribed - Usually located on the anterior aspect of the tibia - Bilateral but not symmetric

Question 31

Erythema nodosum histology (3):

Answer 31

- Septal panniculitis (little to know necrosis of lobule) - Early: widening of septa from fibrin, edema and neutrophilic infiltrate - Chronic: Mononuclear cells and granulomatous inflammation of septum with fibrosis

Question 32

Warts:

Answer 32

Benign growths caused by infection of epidermal cells with HPV

Question 33

Plantar wart (3):

Answer 33

- HPV 1 - Flesh colored papule with hyperkeratotic surface - Found on underside of foot

Question 34

Condyloma acuminatum (3):

Answer 34

- Soft fleshy pink papillomas on the genitalia, perineum and anus - HPV - Most common STD

Question 35

Molluscum contagiosum is caused by:

Answer 35

Poxvirus

Question 36

Molluscum contagiosum lesions (3):

Answer 36

- Asymptomatic smooth, dome-shaped papules with central umbilication - Flesh-colored and translucent - Papules have a cheesy core that can be expressed

Question 37

Scabies is caused by:

Answer 37

Infection with Sarcoptes scabiei

Question 38

Xanthelasma:

Answer 38

Collection of macrophages containing lipid droplets

Question 39

Mongolian spot:

Answer 39

Melanocytes located in the dermis instead of epidermis that may be neural crest cells interrupted in migration

Question 40

Cherry angioma (2):

Answer 40

- Bright red, domed, vascular lesions on trunk | - Benign and increase with age

Question 41

Hemangioma of infancy (3):

Answer 41

- Benign tumor of hyperplastic blood vessels - Blanchable bright red to deep purple lesions - Regression complete by age 10

Question 42

Xeroderma pigmentosum (2):

Answer 42

- Autosomal recessive - Decreased ability to repair DNA following damage by UV light due to defects in excision of abnormal nucleotides or defects in replacement of nucleotides following excision

Question 43

Chediak-Higashi syndrome (2):

Answer 43

- Autosomal recessive - Immunodeficiency due to defect in neutrophil phagosome lysosome fusion causing abnormal giant lysosomal inclusions visible on peripheral blood smear

Question 44

Albinism:

Answer 44

Melanocytes normal in number and location but production of melanin defective due to complete absence of tyrosinase