Types of Pemphigus
Pemphigus comprises five main clinical variants: pemphigus vulgaris (PV), pemphigus foliaceus (PF), pemphigus erythematosus, drug-induced pemphigus, and paraneoplastic pemphigus, with additional rare subtypes including pemphigus herpetiformis, IgA pemphigus, and pemphigus vegetans 1, 2.
Major Pemphigus Variants
Classical Forms
Pemphigus Vulgaris (PV)
- Most common variant affecting both skin and mucous membranes
- Characterized by deep intraepidermal split formation (suprabasilar acantholysis)
- Autoantibodies target desmoglein 3 and/or desmoglein 1
- Often presents with painful oral erosions before skin involvement 1, 3
Pemphigus Foliaceus (PF)
- Superficial variant with blistering in the upper epidermis
- Autoantibodies directed against desmoglein 1 only
- Typically spares mucous membranes
- Presents with crusted erosions and scaling, often in seborrheic distribution 3
Pemphigus Erythematosus
- Localized variant of pemphigus foliaceus
- Combines features of pemphigus and lupus erythematosus
- Typically affects face and upper trunk in a "butterfly" distribution 1
Drug-Induced Pemphigus
Three chemical groups trigger drug-induced pemphigus:
- Thiol drugs (containing sulfhydryl radical) - most commonly cause PF phenotype (70% of cases)
- Phenol drugs
- Non-thiol, non-phenol drugs - tend to trigger PV phenotype 4
Critical distinguishing features:
- Pruritus is more common in drug-induced pemphigus than idiopathic forms
- Latency between drug initiation and disease onset can be several months
- Poor response to standard treatments should raise suspicion
- Recovery after drug withdrawal occurs in approximately 50% (more likely with thiol-triggered cases) 4
Paraneoplastic Pemphigus (PNP)
- Associated with underlying malignancy (lymphoproliferative disorders most common)
- Severe mucosal involvement with polymorphous skin lesions
- Autoantibodies target multiple antigens including plakins
- Worst prognosis among pemphigus variants 5, 2
Rare and Atypical Variants
Pemphigus Herpetiformis
- Presents with grouped vesicles resembling dermatitis herpetiformis
- Histologically shows intraepidermal acantholysis
- Responds to pemphigus-directed therapy 3, 2
IgA Pemphigus
- Two subtypes: subcorneal pustular dermatosis type and intraepidermal neutrophilic type
- Characterized by IgA autoantibodies rather than IgG
- Presents with pustules rather than typical blisters 6, 2
Pemphigus Vegetans
- Rare variant of pemphigus vulgaris
- Characterized by vegetating, hypertrophic plaques in intertriginous areas
- Two subtypes: Neumann type (more severe) and Hallopeau type (milder) 3
Age-Specific Variants
Pediatric Pemphigus
- Childhood PV: affects children <12 years
- Juvenile PV: affects adolescents 12-18 years
- Neonatal pemphigus: self-limiting form due to transplacental transfer of maternal autoantibodies
- Generally more favorable prognosis than adult-onset disease 4
Clinical Pitfalls
When evaluating pemphigus type, obtain:
- Thorough drug history extending back several months (for drug-induced pemphigus)
- Malignancy screening if severe mucosal involvement or atypical features present (for paraneoplastic pemphigus)
- Direct immunofluorescence showing intercellular IgG deposition (except IgA pemphigus)
- Indirect immunofluorescence or ELISA for specific desmoglein antibodies to distinguish PV from PF
The level of intraepidermal split determines the variant: superficial splits indicate PF or pemphigus erythematosus, while suprabasilar splits indicate PV or pemphigus vegetans 1, 3.