Pemphigus erythematosus

Pemphigus erythematosus (Senear-Usher Syndrome) is a rare form of pemphigus with features of pemphigus foliaceus and lupus erythematosus. It was first described by Francis Senear and Barney Usher at the University of Illinois College of Medicine in 1926. Patients with pemphigus erythematosus typically present with flaccid scaling blisters on the face, scalp, and trunk in sun-exposed areas. Patients may also have a butterfly-shaped malar rash similar to systemic lupus erythematosus.

Pemphigus is an autoimmune disease that involves antibodies targeting a protein called desmoglein in the top layer of the skin that holds skin cells together. The proteins are destroyed or disabled by the immune system, leading to the separation of the skin layers, which causes the blisters. The separation itself is called acantholysis.

Patients with pemphigus erythematosus have antibodies against desmoglein-1 primarily, similar to pemphigus foliaceus. Pemphigus erythematosus and pemphigus foliaceus both exhibit superficial blistering of the skin with minimal involvement on the mucosa (eg. mouth). This is in contrast to pemphigus vulgaris, which has antibodies against desmoglein-3 primarily. Patients with pemphigus erythematosus will have positive ANA serology, a common feature of lupus.