Bullae and Desquamation Disorders

Question 1

structures that work to adhere cells to one another

Answer 1

Desmosomes

Question 2

proteins inside desmosomes to allow for normal desmosome formation

Answer 2

Desmogleins

Question 3

what holds the epidermis together?

Answer 3

Hemidesmosomes join cells of the epidermal basement membrane to the basilar membrane

Question 4

• Autoimmune disorder
• Loss of cell to cell adhesion in the epidermis
• circulating antibodies of IgG that bind to desmogleins transmembrane glycoproteins in the desmosomes
• Autoantibodies interfere with adhesion = acantholysis

Answer 4

pemphigus

Question 5

2 types of pemphigus

Answer 5

1. Pemphigus Vulgaris: flaccid blisters on skin and erosions on mucous membranes
2. Pemphigus Foliaceus: scaly and crusted skin lesions

Question 6

pemphigus MC in who?

Answer 6

• Pemphigus Vulgaris - jewish/mediterranean
• Pemphigus Foliaceus - brazil
• 40-60 years old
• M:F = incidence

Question 7

1. Vesicles and bullae w/ serous content
2. Flaccid/easily ruptured weeping
3. Arising on normal skin
4. Scattered & discrete - Localized or generalized with random pattern; Extensive erosions = bleed easily
5. Nikolsky Sign

Answer 7

pemphigus

Question 8

Dislodging or normal appearing epidermis by lateral finger pressure in the vicinity of lesions
Pressure on bulla = lateral extension

what is this sign?
MC areas?

Answer 8

Nikolsky Sign

1. Scalp
2. Face
3. Chest
4. Axillae
5. Groin
6. Umbilicus

Question 9

s/s of pemphigus vulgaris

Answer 9

• Starts in oral mucosa
• Months may elapse before actual skin lesions
• burning/pain, No pruritus
• Painful mouth lesions = inadequate food intake
• Epistaxis
• Hoarseness
• Dysphagia
• Weakness
• Malaise
• Weight loss

Question 10

s/s of pemphigus foliaceus

Answer 10

1. No mucosal involvement
2. Cutaneous lesions
3. initial lesions: flaccid bullae, quickly ruptures, leaving superficial erosion
4. MC sites: face, scalp, upper chest, abdomen

Question 11

w/u for pemphigus

Answer 11

1. bx of edge of blister: (+) deposits of IgG
   - Direct immunofluorescence (IF) staining: IgG and C3 deposited in lesional and paralesional skin; performed on normal-appearing skin adjacent to a lesion
2. ELISA for IgG ab to desmogelin 1 & 2
   - PF +a-Dsg1
   - PF + a-Dsg3 and Dsg 1

Question 12

tx for pemphigus

Answer 12

1. prednisone until no new blisters or nikolsky
2. Concomitant Immunosuppressive: azathioprine / mycophenolate mofetil (Cellcept)
3. wound care: wet compressions, routine bathing, anticipate infection

Question 13

complications of pemphigus

Answer 13

1. Fluid and electrolyte imbalances
2. Secondary bacterial infections
3. Osteoporosis - Calcium/Vit D supplementation

Question 14

• Rare autoimmune disease MC in elderly pts (60-80)
• Interaction of autoantibody with BP antigen
• MC bullous autoimmune disease

Answer 14

bullous pemphigoid

Question 15

pathophys of bullous pemphigoid

Answer 15

• BPAG1 & BPAG2 In hemidesmosomes of basal keratinocytes
• Followed by complement and mast cell activation, attraction of neutrophils and eosinophils, release multiple bioactive molecules from inflammatory cells

Question 16

1. Prodrome (weeks - months): Pruritus, Urticaria and papular lesions
2. large, tense, firm-topped bullae
3. serous or hemorrhagic fluid
4. painful erosions after rupture
5. (-) Nikolsky
6. MC sites: axilla, medial thigh, groin, abdomen, ventral forearm, lower legs
7. Oral lesions: less severe and less painful than pemphigus

Answer 16

bullous pemphigoid

Question 17

w/u for bullous pemphigoid and findings

Answer 17

1. Bx (Gold Standard): Linear IgG deposits along basement membrane
   - Perilesional skin
   - C3 may occur in absence of IgG
2. DIF study: IgG ab present in 70% of pts
3. ELISA - BPAG1 and BPAG2
   - highly sensitive and specific
   - few labs perform this test

Question 18

tx for bullous pemphigoid

Answer 18

1. refer
2. prednisone
3. +/- azathioprine
4. +/- topical steroids

Question 19

complications of bullous pemphigoid

Answer 19

1. Fluid and electrolyte imbalances
2. Secondary bacterial infections
3. Osteoporosis - Calcium/Vit D supplementation

Question 20

Acute hypersensitivity reaction affecting the skin and mucous membranes
Sometimes eye involvement

Answer 20

erythema multiforme

Question 21

causes of erythema multiforme? which is MC?

Answer 21

1. HSV (MC)
2. Mycoplasma
3. Sulfonamides
4. PCN
5. Allopurinol
6. Barbiturates
7. Phenytoin
8. Phenylbutazone

Question 22

s/s of erythema multiforme

Answer 22

1. Erythematous, papular, or urticarial type lesion
   - May precede bullae formation by months
   - Bullae small or large
   - Tense, firm topped oval or round
   - on normal, erythematous, or urticarial skin: serous / hemorrhagic; Localized / generalized; Pruritic and painful
2. Mucosal Lesions: Erosions and ulcerations
   - Lips, oropharynx, nasal, conjunctival, vulvar, anal; Eyes- corneal ulcer, anterior uveitis
3. Fever, weakness, malaise, and fatigue
4. bilateral and symmetrical

Question 23

Minor EM presentation

Answer 23

1. Little - no mucosal involvement
2. (+) vesicle, (-) bullae
3. no systemic symptoms
4. confined to extremities & face

Question 24

Major EM presentation

Answer 24

1. mucosal involvement
2. confluence of lesions
3. (+) Nikolsky sign
4. (+) constitutional symptoms
5. cheilitis/stomatitis
6. vulvitis/balanitis
7. eye involvement
8. MCC - drug reaction

Question 25

mgmt for EM minor

Answer 25

1. self limiting - remove underlying cause if applicable 1. **antihistamines** for pruritus 1. **topical steroids**: low dose - face/intertriginous; medium dose trunk/extremities 1. **antivirals** if needed 1. painful oral lesions: - high dose **fluocinonide** 0.05% gel 2-3x/d - **throat Soothie**/Magic Swizzle

Question 26

ingredients for throat smoothie/magic swizzle

Answer 26

1. 1:1 of lidocaine viscous 1. diphenhydramine (Benadryl) 1. magnesium hydroxide (Maalox) 1. +/- dexamethasone 1 tsp swish, gargle and spit/swallow q6h prn

Question 27

tx for EM major

Answer 27

1. DC offending agent/**tx HSV** if indicated 1. Mucocutaneous lesions - IV fluids if needed - **Throat Soothie**/Magic Swizzle - high dose PO **prednisone** - Oral/parenteral **pain control** - **Wet compresses w/ Burow's solution** for large erosions 1. Ocular involvement- Immediate referral/consult ophthalmology

Question 28

tx and complications of recurrent EM

Answer 28

1. Daily prophylactic antiviral therapy - Complications: Secondary bacterial infection; Fluid/electrolyte imbalances

Question 29

Cytotoxic event caused by an immune response results in destruction of keratinocytes

Answer 29

SJS & TEN

Question 30

causes of SJS & TEN

Answer 30

1. MC drugs 1. Chemicals 1. Mycoplasma 1. Viral infections 1. Immunization

Question 31

s/s SJS/TEN

Answer 31

1. Fever, Chills, Malaise 1. Headache, Sore throat, N/V/D 1. Skin tenderness 2. Abrupt onset of lesions - Macule, papule, central vesicle/bullae, erosions - Target lesion = 2 zones of color - Rapid confluence - +Nikolsky sign - Trauma - full thickness epidermal detachment: Red, oozing dermis 3. distribution: Face and extremities - generalized 4. Mucosal findings: Very painful, erythematous, erosions - Lips, Buccal mucosa, Conjunctiva, Genitalia, Anal region 5. Eyes: Conjunctivitis, Keratitis, Synechia of the lid and conjunctiva 6. Hair and nail: Loss of lashes and nails (TEN)

Question 32

when is SJS/TEN an emergency?

Answer 32

Systemic symptoms: Fever, HR >120 (Sloughing of epidermis)

Question 33

w/u and classification of SJS/TEN

Answer 33

1. clinically 2. Classification: - SJS = < 10% body surface - SJS/TEN = 10-30% - TEN = > 30% 3. bx will aid

Question 34

tx for SJS/TEN

Answer 34

1. d/c offending agent 1. IV Fluids 1. Parenteral nutrition 1. IV Pain meds 1. Wound care: Wet dressing with burow's solution; Non adherent dressing; Eye- saline and erythromycin ointment 1. IV Steroids/IVIG = early