Pemphigus Flashcards
What are the five main variants of pemphigus
Vulgaris, foliaceous, erythematosus, drug-induced, and paraneoplastic
Autoantibodies in Pemphigus
IgG against desmogleins. 3 in vulgaris and 1 in foliaceous
- in mucosal dominant PV: Dgs3 only
- in mucocutaneous PV: Dsg 3 and 1
PV clinical presentation
Oral ulcers weeks to months before skin blisters (MC sites are scalp, face, axilla, and oral cavity)
+ Nikolsky’s sign
Pemphigus vegetans
Variant of pemphigus vulgaris where patient gets large verrucous confluent papules and pustules in axilla and groin
Pemphigus erythematosus aka
Senear-Usher syndrome
Clinical presentation of pemphigus erythematosus
Combo of localized pemphigus folieacous and SLE (patients have + ANA)
Pemphigus folicaeous clinical presentation
reccurent shallow ulcers with crusting and erythema. Mucous membrane involvement is uncommon
- usually starts on face and involves seborrheic distribution
Fogo Selvagem
endemic form of pemphigus foliaceous found in certain rural areas of South America (indistinguishable from non-endemic form)
H&E findings in Pemphigus
Basal cells remain attached to basement membrane with separation above (tombstone sign)
DIF in pemphigus
IgG, IgG4, and frequently C3 in chicken wire pattern
IIF in pemphigus
ELISA for Desmoglein 1&3 to distinguish between foliaceous and vulgaris
Tx of pemphigus vulgaris
Topical steroids (clobetasol), systemic steroids, steroid sparing agents such as azathioprine/Cellcept/Rituximab/IVIG/cyclophosphamide
- alternative: nicotinamide + tetra/minocycline
- UV protection is important
Adverse effects of Cellcept
GI, GU, increased infections, and neurologic symptoms
Adverse effects of cyclophosphamide
Bone marrow suppression, hemorrhagic cystitis, bladder fibrosis, reversible alopecia, increased risk of bladder carcinoma and lymphoma
Adverse effects of azathioprine
Bone marrow suppression, hepatotoxicity, increased risk of malignancy (but lower than cyclophosphamide)
Remission rates in Pemphigus vulgaris
Mucocutaneous patient have significantly lower rate of remission compared with those with only cutaneous or only mucous involvement
When to stop treatment for PV
Clinically free of disease and negative DIF (circulating antibodies are not sufficient enough)
Diseases associated with Pemphigus
Myasthenia gravis and thymoma (usually with erythematosus and vulgaris subtypes). These usually present before the skin findings
Drug induced vs. drug triggered pemphigus
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%
Paraneoplastic pemphigus
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.
Antibodies in paraneoplastic pemphigus
antibodies against epithelial proteins are present in desmosomes and hemidesmosomes in both the epidermis and respiratory epithelium
Prognosis of paraneoplastic pemphigus
Poor, usually see progressive respiratory failure with bronchiolitis obliterans
Histology of paraneoplastic pemphigus
intraepithelial clefts with epidermal acantholysis
DIF of paraneoplastic pemphigus
IgG and C3 on cell surface and C3 granular deposits along BMZ
IIF of paraneoplastic pemphigus
used to differentiate paraneoplastic from PV
- see circulating IgG anti-cell-surface and anticytoplasmic antibodies
