Pemphigus

Question 1

What are the five main variants of pemphigus

Answer 1

Vulgaris, foliaceous, erythematosus, drug-induced, and paraneoplastic

Question 2

Autoantibodies in Pemphigus

Answer 2

IgG against desmogleins. 3 in vulgaris and 1 in foliaceous

• in mucosal dominant PV: Dgs3 only
• in mucocutaneous PV: Dsg 3 and 1

Question 3

PV clinical presentation

Answer 3

Oral ulcers weeks to months before skin blisters (MC sites are scalp, face, axilla, and oral cavity)
+ Nikolsky’s sign

Question 4

Pemphigus vegetans

Answer 4

Variant of pemphigus vulgaris where patient gets large verrucous confluent papules and pustules in axilla and groin

Question 5

Pemphigus erythematosus aka

Answer 5

Senear-Usher syndrome

Question 6

Clinical presentation of pemphigus erythematosus

Answer 6

Combo of localized pemphigus folieacous and SLE (patients have + ANA)

Question 7

Pemphigus folicaeous clinical presentation

Answer 7

reccurent shallow ulcers with crusting and erythema. Mucous membrane involvement is uncommon
- usually starts on face and involves seborrheic distribution

Question 8

Fogo Selvagem

Answer 8

endemic form of pemphigus foliaceous found in certain rural areas of South America (indistinguishable from non-endemic form)

Question 9

H&E findings in Pemphigus

Answer 9

Basal cells remain attached to basement membrane with separation above (tombstone sign)

Question 10

DIF in pemphigus

Answer 10

IgG, IgG4, and frequently C3 in chicken wire pattern

Question 11

IIF in pemphigus

Answer 11

ELISA for Desmoglein 1&3 to distinguish between foliaceous and vulgaris

Question 12

Tx of pemphigus vulgaris

Answer 12

Topical steroids (clobetasol), systemic steroids, steroid sparing agents such as azathioprine/Cellcept/Rituximab/IVIG/cyclophosphamide

• alternative: nicotinamide + tetra/minocycline
• UV protection is important

Question 13

Adverse effects of Cellcept

Answer 13

GI, GU, increased infections, and neurologic symptoms

Question 14

Adverse effects of cyclophosphamide

Answer 14

Bone marrow suppression, hemorrhagic cystitis, bladder fibrosis, reversible alopecia, increased risk of bladder carcinoma and lymphoma

Question 15

Adverse effects of azathioprine

Answer 15

Bone marrow suppression, hepatotoxicity, increased risk of malignancy (but lower than cyclophosphamide)

Question 16

Remission rates in Pemphigus vulgaris

Answer 16

Mucocutaneous patient have significantly lower rate of remission compared with those with only cutaneous or only mucous involvement

Question 17

When to stop treatment for PV

Answer 17

Clinically free of disease and negative DIF (circulating antibodies are not sufficient enough)

Question 18

Diseases associated with Pemphigus

Answer 18

Myasthenia gravis and thymoma (usually with erythematosus and vulgaris subtypes). These usually present before the skin findings

Question 19

Drug induced vs. drug triggered pemphigus

Answer 19

Drug induced: THIOL drugs such as penicillamine and captopril. Pemphigus foliaceous pattern. Often spontaneously resolves after drug discontinuation
Drug-triggered: only see spontaneous resolution in ~15% and mortality is 10%

Question 20

Paraneoplastic pemphigus

Answer 20

Looks like overlap between SJS and PV. painful mucosal ulcerations, conjunctival reactions, and polymorphous skin lesions on trunk and extremities that usually progress to blisters.

Question 21

Antibodies in paraneoplastic pemphigus

Answer 21

antibodies against epithelial proteins are present in desmosomes and hemidesmosomes in both the epidermis and respiratory epithelium

Question 22

Prognosis of paraneoplastic pemphigus

Answer 22

Poor, usually see progressive respiratory failure with bronchiolitis obliterans

Question 23

Histology of paraneoplastic pemphigus

Answer 23

intraepithelial clefts with epidermal acantholysis

Question 24

DIF of paraneoplastic pemphigus

Answer 24

IgG and C3 on cell surface and C3 granular deposits along BMZ

Question 25

IIF of paraneoplastic pemphigus

Answer 25

used to differentiate paraneoplastic from PV

- see circulating IgG anti-cell-surface and anticytoplasmic antibodies