Immunobullous disorders: there are several immunobullous
blistering diseases, of which pemphigus and pemphigoid are the
most common. Autoantibodies in these diseases are targeted
against specific antigens within the epidermal structure (e.g.
intraepithelial in pemphigus and subepithelial in pemphigoid).
Three major types of pemphigus have been described, of which
pemphigus vulgaris (PV) is the most common. PV usually presents
with pain and easily ruptured blisters in the oropharynx
and may involve the skin as well. Mucous-membrane pemphigoid
may be associated with ocular or genital involvement. In
both cases, diagnosis requires a biopsy and the demonstration of
the appropriate autoantibody, at the appropriate site, on direct
immunofluorescence. Treatment often requires systemic corticosteroids
and subsequent maintenance immunomodulatory
agents, such as azathioprine, mycophenolate mofetil or cyclophosphamide.
Rituximab, a chimeric anti-CD20 monoclonal
antibody, may also be used.