16: Immune-Mediated Mucocutaneous Diseases

Question 1

Pemphigus Vulgaris: Overview

Answer 1

Autoimmune

Autoantibodies destroy desmosomes

Question 2

Pemphigus Vulgaris: Population

Answer 2

Adults, 30s-50s

Question 3

Pemphigus Vulgaris: Clinical

Answer 3

50% oral lesions “First to show, last to go”
Ragged erosions + ulcerations
Flaccid bullae on skin, none intact in mouth
Positive Nikolsky sign

Question 4

Pemphigus Vulgaris: Immunopathologic

Answer 4

Positive DIF (and IIF)
Autoantibodies bind desmosomal components (desmoglein 3 & 1)

Question 5

Pemphigus Vulgaris: Histopathology

Answer 5

Intraepithelial (aka suprabasilar) clefting
Acantholysis = breakdown of spinous layer
“Dilapidated brick wall” with intact basal cell layer

Question 6

Pemphigus Vulgaris: Treatment

Answer 6

Systemic (not topical) corticosteroids

Question 7

Pemphigus Vulgaris: Prognosis

Answer 7

Fatal if not treated

Now 5-10% mortality due to complications

Question 8

Mucous Membrane Pemphigoid: Overview

Answer 8

aka Cicatricial Pemphigoid
Blisters resemeble pemphigus
2-4x more common than pemphigus

Question 9

Mucous Membrane Pemphigoid: Population

Answer 9

2:1 female, 50-60 yo

Question 10

Mucous Membrane Pemphigoid: Clinical Presentation

Answer 10

Any mucosal surface
Scarring with conjunctival and cutaneous lesions
Desquamative gingivitis
Intact intraoral blisters

Question 11

Mucous Membrane Pemphigoid: Ocular Involvement

Answer 11

Significit

Scarring –> symblepharons = adhesion formation between eyelid and globe

Question 12

Mucous Membrane Pemphigoid: Histopathology

Answer 12

Clean subepithelial cleft

Separates intact epi at CT from BMZ

Question 13

Mucous Membrane Pemphigoid: Immunopathology

Answer 13

Normal mucosa (.5-1cm from ulceration/erythema)
Submitted in Michel’s solution and formalin
Linear deposition of immuinoreactants at BMZ
Positive DIF, negative IIF

Question 14

Mucous Membrane Pemphigoid: Treatment

Answer 14

Depends on involvement
Oral: topical corticosteroids
Ocular: systemic immunosuppressive

Question 15

Mucous Membrane Pemphigoid: Prognosis

Answer 15

Rarely fatal
Ocular –> blindness
Rare spontaneous resolution

Question 16

Bullous Pemphigoid: Population

Answer 16

Older, 75-80

Question 17

Bullous Pemphigoid: Clinical Presentation

Answer 17

Mostly cutaneous lesions, 10-20% oral

Pruritus, then cutaneous blisters

Question 18

Bullous Pemphigoid: Histopathology

Answer 18

Subepithelial cleft (like MMP)
Positive DIF + IIF
Immunoreactants deposited at BMZ

Question 19

Bullous Pemphigoid: Treatment

Answer 19

Like MMP

Immunosuppressive can have serious SE

Question 20

Bullous Pemphigoid: Prognosis

Answer 20

Can spontaneously resolve 1-2 years

Question 21

Erythema Multiforme: Overview

Answer 21

Acute, self-limited ulcerative disorder
Immune mediated
50% unknown
50% infection, medication

Question 22

Erythema Multiforme: Population

Answer 22

Young adult female

Question 23

Erythema Multiforme: Disease Spectrum

Answer 23

EM minor: skin, oral mucosa only
EM major: 2+ mucosal sites + skin
Steven’s Johnson Syndrome: 30% body sites

Question 24

Erythema Multiforme: Clinical Features

Answer 24

Hemorrhagic lip crusting
Oral ulcers with ragged margins
“Target” skin lesions

Question 25

Erythema Multiforme: Sites

Answer 25

Labial + buccal mucosa, tongue

Question 26

Erythema Multiforme: Histopathology

Answer 26

``` Characteristic, not diagnostic Keratinocyte destruction Subepithelial edema Mixed inflammatory infiltrate Perivascular inflammation Non-specific DIF ```

Question 27

Erythema Multiforme: Treatment

Answer 27

EM minor: supportive EM major: corticosteroids (controversial) TEN: IV pooled human Ig

Question 28

Erythema Multiforme: Prognosis

Answer 28

20% cases recur EM major: 1-5% mortality TEN: 25-30% mortality, but now improved

Question 29

Erythema Migrans: Overview

Answer 29

aka Bengin Migratory Glossitis, Geographic Tongue Common, 1-3% Immune-mediated

Question 30

Erythema Migrans: Clinical

Answer 30

With fissured tongue Lesions wax + wane Ectopic geographic tongue = on non-keratinized mucosal surfaces

Question 31

Erythema Migrans: Histopathology

Answer 31

Biopsy shows "psoriasiform mucositis" Parakeratosis with microabscess in upper spinous layer Lose superficial keratin --> thins --> red

Question 32

Erythema Migrans: Treatment

Answer 32

None | Topical corticosteroid gel if sensitive