Paraneoplastic pemphigus. A report of two cases associated with chronic B-cell lymphocytic leukaemia

Paraneoplastic pemphigus (PNP) is an autoimmune blistering and erosive muco cutaneous disease associated with neoplasia. Clinical manifestations are po lymorphous, and include erythema, bullae, erythema multiforme-like lesions and severe mucous membrane involvement. PNP manifesting as lichenoid dermat itis has recently been observed. We describe two Italian men with fatal PNP featuring typical PNP autoantigens associated with chronic B-cell lymphocy tic leukaemia. The first patient presented with an extensive blistering eru ption, several erythema multiforme-like lesions and severe mucosal involvem ent. The second patient presented with a lichenoid dermatitis, then develop ed bullae, and died with an erythrodermic and exfoliative dermatosis resemb ling pemphigus foliaceus. Our patients represent two Italian cases of well- documented PNP. In patient 2, the sequence of clinical presentations was un ique, and strongly supports the hypothesis of epitope spreading through chr onic lichenoid inflammation of the dermo-epidermal junction exposing new se lf antigens, leading to the humoral response characteristic of PNP.