52 - Pemphigus

Question 1

4 types of pemphigus

Answer 1

Vulgaris
Foliaceus
Paraneoplastic
IgA pemphigus

Question 2

Localized forms of pemphigus vulgaris

Answer 2

Pemphigus vegetans of Hallopeau > Pemphigus vegetans of Newman (more extensive)

Question 3

Localized form of pemphigus foliaceus

Answer 3

Pemphigus erythematosus

Question 4

More common in Jews and probably in people of Mediterranean descent and from the Middle East

Answer 4

Pemphigus vulgaris

Question 5

Endemic foci of pemphigus foliaceus in Brazil, Colombia, and Tunisia

Answer 5

Fogo selvagem

Question 6

Fogo selvagem vs pemphigus foliaceus

Answer 6

Fogo selvagem - children and young adults; anyone in an endemic area may be susceptible
Sporadic PF - middle- aged and older patients; in genetically related family members

Question 7

Positive Nikolsky sign differentials

Answer 7

Pemphigus vulgaris
SSSS
SJS-TEN

Question 8

Pemphigus vegetans sites of predilection

Answer 8

Intertriginous areas
Scalp
Face

Question 9

Pemphigus vegetans prognosis

Answer 9

Milder disease and higher chance of remission

Question 10

Mucous membranes most often affected by PV

Answer 10

Orophryngeal cavity

Nasal mucosa

Question 11

In the majority of patients, _____ are the presenting sign of PV

Answer 11

Painful mucous membrane erosions

Question 12

Features of a pemphigus-lupus erythematosus overlap

Answer 12

Senear-Usher syndrome

Question 13

Drug-induced pemphigus caused by

Answer 13

Penicillamine

Captopril

Question 14

Thiol-containing foods such as _____ may precipitate PV

Answer 14

Garlic
Leek
Onion

Question 15

Diseases associated with PV and PF

Answer 15

Myasthenia gravis

Thymoma

Question 16

Pemphigus autoantigens

Answer 16

Desmogleins

Question 17

PF antigen

Answer 17

Desmoglein 1

Question 18

PV antigen

Answer 18

Desmoglein 3

Question 19

Antibodies in mucosal-dominant PV

Answer 19

Anti-desmoglein 3 antibodies

Question 20

Neonatal pemphigus resolves by approximately

Answer 20

6 months - concurrent with the disappearance of maternal IgG from the circulation

Question 21

Constant region of the antibody is required for blister formation in _____. In _____, the variable region of the antibody is sufficient

Answer 21

Pemphigoid and EBA

Pemphigus

Question 22

Pathogenic ang predominant IgG subclass in PV and PF

Answer 22

IgG4

Question 23

Pathogenic PV and PF autoantibodies bind calcium-sensitive conformational epitopes in the _____, whereas nonpathogenic antibodies tend to bind more _____

Answer 23

Amino terminal extracellular domains of desmogleins

Membrane proximal extracellular domains

Question 24

Hypothesis which proposes that pathogenic antibodies directly interfere with desmoglein adhesive interactions, causing acantholysis

Answer 24

Steric hindrance

Question 25

Autoantibodies against one desmoglein isoform inactivate only that isoform and that another isoform co-expressed in the same area can compensate in adhesion

Answer 25

Desmoglein compensation

Question 26

The depletion of desmogleins by pemphigus antibodies may lead to loss of desmogleins resulting in smaller desmosomes and/or their defective function in adhesion, a scenario referred to as

Answer 26

Dsg nonassembly depletion hypothesis

Question 27

Among Ashkenazi Jews with PV, the serologically defined HLA-_____ is predominant, whereas in other ethnic groups with PV, the _____ allele is more common

Answer 27

DR4 | DQ1

Question 28

DIF sample

Answer 28

Perilesional skin

Question 29

IIF sample

Answer 29

Serum

Question 30

ELISA sample

Answer 30

Serum

Question 31

Hallmark of pemphigus is the finding of _____ autoantibodies against the cell surface of keratinocytes

Answer 31

IgG

Question 32

DIF finding in pemphigus erythematosus

Answer 32

IgG and C3 in the basement membrane zone in addition to the epidermal cell surface IgG

Question 33

Can remain positive for weeks to months after healing of the skin lesions, making it a good diagnostic test if a patient should present with no active lesions

Answer 33

IIF

Question 34

Substrate that is more sensitive for detecting PV antibodies

Answer 34

Monkey esophagus

Question 35

Superior substrate for detecting PF antibodies

Answer 35

Guinea pig esophagus or normal skin

Question 36

Test that can differentiate PV and PF

Answer 36

ELISA

Question 37

Often the cause of death in PV and PF

Answer 37

Infection

Question 38

Initiation of treatment for PV vs PF

Answer 38

PV - should be treated at its onset, because it will ultimately generalize and the prognosis without therapy is very poor PF - may be localized for years; do not necessarily require treat with systemic therapy - use of topical corticosteroids may suffice

Question 39

Mainstay of therapy for pemphigus

Answer 39

Systemic administration of glucocorticoids

Question 40

Full systemic dose of glucocorticoids for pemphigus

Answer 40

1.5 mg/kg/d of prednisone equivalent for 2-3 weeks

Question 41

Monoclonal anti-CD20 antibody approved by the FDA for therapy of pemphigus

Answer 41

Rituximab

Question 42

Immunosuppressive drugs that may offer protection against Pneumocystis carinii infection

Answer 42

MMF | Dapsone

Question 43

Side effects of IVIg

Answer 43

Stroke Deep venous thrombosis Aseptic meningitis

Question 44

Treatment for pemphigus that does not increase the risk of infection

Answer 44

IVIg

Question 45

Side effects of cyclophosphamide

Answer 45

Hematuria Infection Transitional cell carcinoma of the bladder Infertility