Paraneoplastic Pemphigus

Excerpt

Paraneoplastic pemphigus (PNP) is a rare, autoimmune-mediated mucocutaneous disease that is almost always associated with an underlying neoplasm. Pemphigus comprises a group of IgG-mediated autoimmune bullous diseases in which autoantibodies react with desmosomes, the cell-to-cell adhesion structures between keratinocytes, resulting in painful skin erosions and blisters. Researchers have identified three significant forms of pemphigus: pemphigus foliaceus, pemphigus vulgaris (most common type), and paraneoplastic pemphigus.

Paraneoplastic pemphigus typically presents with painful mucosal erosions and dusky patches on the skin that later desquamate. A variety of lesions with differing morphologies, ranging from flaccid blisters to widespread lichenoid eruptions, have been seen in paraneoplastic pemphigus patients. However, shared by all patients is the presence of widespread, and often severe, mucosal lesions that can be the earliest presenting symptom of the disease. Extensive epidermal loss can result in extreme dehydration, protein depletion, and an increased risk of infection. Patients often require intensive care and should be managed, similar to burn patients. Adults ages 45 to 70 years are most commonly affected, though children can develop PNP. It was first identified in 1990 by Anhalt, who proposed the initial set of diagnostic criteria. The term “paraneoplastic autoimmune multiorgan syndrome” (PAMS) has since been coined to account for the variable non-bullous cutaneous manifestation and additional systemic findings, such as bronchiolitis obliterans. Mortality rates approach 90% in PNP.