(Figures 3.24A–C and 3.25A) - Potentially fatal autoimmune bullous disease of the skin and mucous membranes
- Autoantigen: cadherin family, desmosomal protein
- Desmoglein 3 (mucosal)
- Desmoglein 1 (mucocutaneous)
- Clinical: flaccid vesicles/bullae which rupture leaving large, painful erosions with bleeding and crusting; erosions may also be in nose, mouth, larynx, pharynx, vagina; + Nikolsky sign, + Asboe-Hansen sign (pressure to surface of blister causes lateral spread)
- Pemphigus vegetans (variant of PV): vegetating plaques in scalp and intertriginous areas; histology similar to PV + pseudoepitheliomatous hyperplasia, ↑↑ inflammatory cell infiltrate, intraepidermal microabscesses with eosinophils and neutrophils
- Drug-induced: thiol drugs (penicillamine, captopril, enalapril, lisinopril, piroxicam), pyrazolone derivatives (phenylbutazone, oxyphenylbutazone), antibiotics (penicillin derivates, cephalosporin, rifampicin)
- Histology: suprabasal cleavage with acantholytic keratinocytes, ‘tombstone row’ of basal cells attached to basement membrane, perivascular lymphocytes and eosinophils, acantholysis may involve hair follicles
- DIF: intercellular IgG4 ≥ C3 (net-like pattern in epidermis, more pronounced in lower epidermis)
- IIF: monkey esophagus, + in 80–90% cases, titer correlates with disease activity
- Treatment: oral corticosteroid, methotrexate, azathioprine, mycophenolate mofetil, plasmapheresis, IVIG, rituximab
| | | | | | Associations: HLA-DR4, HLA-DRw6, HLA-DR14 | | | | | |
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| | Figure 3.25
A: DIF, pemphigus vulgaris
(Courtesy of Dr. Paul Getz)
B: Pemphigus foliaceous
(Courtesy of Dr. Paul Getz)
C: Paraneoplastic pemphigus |
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