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Pemphigus (vulgaris and foliaceus)
In pemphigus, autoantibodies against desmogleins break the junctions between keratinocytes (acantholysis), producing flaccid intra-epidermal blisters that rupture quickly and leave painful erosions; pemphigus vulgaris usually starts in the mouth.
Why it matters in the exam
Exam stems show an adult with painful mouth ulcers for weeks, then erosions on the trunk, with a positive Nikolsky sign. The question turns on separating pemphigus from bullous pemphigoid, vulgaris from foliaceus by the antibody (desmoglein 3 or 1), and ordinary from paraneoplastic pemphigus. Also asked are the direct immunofluorescence pattern — a "fishnet" around the cells — and the current recommendation to give rituximab first line together with steroids. Remember that the disease is relatively common in Ashkenazi Jews and people of Mediterranean origin, that it can follow thiol drugs such as penicillamine and captopril, and that before the steroid era it was fatal in most cases. ELISA antibody levels also help to follow disease activity and to decide on tapering treatment.
Key points
- Pemphigus is an autoimmune blistering disease in which antibodies against desmogleins cause acantholysis and flaccid intra-epidermal blisters.
- Pemphigus vulgaris usually begins with painful oral erosions and targets desmoglein 3; foliaceus targets desmoglein 1 and spares the mucosa.
- Diagnosis includes biopsy for histology, direct immunofluorescence with an intercellular pattern and ELISA tests for antibodies.
- The accepted treatment for moderate to severe disease is rituximab with prednisone, with a gradual steroid taper.
- Paraneoplastic pemphigus is linked to lymphoma and Castleman tumour and presents with severe stomatitis and lung involvement.
Summary table
| Type | Antibody and target | Clinical picture | Key distinction |
|---|---|---|---|
| Pemphigus vulgaris | Antibodies against desmoglein 3 (sometimes also 1) | Painful oral erosions, then flaccid blisters and erosions on the skin | Suprabasal split with a "tombstone" row of basal cells |
| Pemphigus foliaceus | Antibodies against desmoglein 1 only | Scale and crust on the face, scalp and upper trunk, no mucosal involvement | High split in the epidermis, just under the stratum corneum |
| Paraneoplastic pemphigus | Antibodies against plakins and desmogleins | Severe, resistant stomatitis, varied rash, lung involvement | Linked to lymphoma, CLL and Castleman tumour |
| Drug-induced pemphigus | Caused by drugs with a thiol group | Usually foliaceus-like | Penicillamine, captopril; improves when the drug is stopped |
| Bullous pemphigoid (for comparison) | Antibodies against BP180 and BP230 | Tense blisters in older adults, itch, mucosa usually spared | Subepidermal split, linear IgG and C3 along the basement membrane |
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Sources
- S2K guideline on diagnosis and treatment of pemphigus vulgaris and foliaceus (EADV), 2020 — Diagnosis and first-line treatment
- International consensus on the management of pemphigus, 2020 — Rituximab and corticosteroids
- British Association of Dermatologists guidelines for the management of pemphigus vulgaris, 2017 — Treatment
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.