Table 1 Salient features to differentiate between pemphigus vulgaris and paraneoplastic pemphigus

Clinical findings

• Oral erosions particularly on the labial and buccal mucosa

• Painful, progressive stomatitis involving the tongue

• Blisters and targetoid lesions on the palms and soles

Direct immunofluorescence

• Intercellular deposition of IgG and C3 in “chicken-wire” lattice pattern

• IgG deposition in all layers of the epidermidis and C3 in the lower epidermis and basement membrane

• Intercellular staining is focal and faint

Autoantibodies

• Autoantibodies against desmoglein-1 and desmoglein-3

• Autoantibodies against desmoglein-1 and desmoglein-3

• Autoantibodies against proteins in the plakin family (plectin, desmoplakin I, desmoplakin II, bullous pemphigoid antigen I, envoplakin, and periplakin)

Visceral involvement

• Very rare

• Mucous membranes of the esophagus, stomach, duodenum, intestines, and pulmonary epithelium