subject: Pemphigus vulgaris aetiology, pathogenesis and management [print this page] Pemphigus vulgaris aetiology, pathogenesis and management
Pemphigus vulgaris is an uncommon, chronicintraepidermal blistering disease of unknown aetiology,characterized by the presence in affected skin and mucosaof an IgG antibody which localizes to the cell wall of keratinocytes. A split forms within the epidermis.
Aetiology and pathogenesis The disease is most common in middle age and in AshkenaziJews. The characteristic antibody is usually found in thebloodstream, and antibody titres correlate approximatelywith disease activity. Relapse is sometimes shown to bepreceded by an increased titre. The pemphigus antibodyprobably brings about separation of keratinocytes byactivating proteinases. Occasionally pemphigus is associatedwith other immunological diseases, e.g. thymoma,myasthenia gravis and SLE.
Clinical features Pemphigus often begins in the mouth and sometimes othermucous membranes, with non-healing erosions. Blistersappear sooner or later on previously normal-looking skin,and when the disease is active sideways pressure with afinger on unblistered skin can produce new blisters (Nikolskysign). Increasing numbers of flaccid blisters appearand, when they burst, leave erosions. The resultant problemsof infections and fluid loss are similar to the consequencesof extensive burns.
Diagnosis The diagnosis is made from characteristic histology,showing a suprabasal split and free-floating keratinocytes(acantholysis). Immunohistochemical techniques showthat the keratinocytes are coated with IgG. In all but localizedor treated disease the pemphigus antibody can bedemonstrated in the serum.
Treatment Treatment is with high doses of corticosteroids (about80mg prednisolone daily), together with an immunosuppressantsuch as azathioprine, with subsequent gradualreduction of the steroid. Gold salts have also been usedwith success, but toxicity is a problem. Even with treatmentpemphigus remains a serious disorder, up to 25% ofpatients dying from the disease or the consequences oftreatment. Most patients need maintenance therapy forlengthy periods, although in some a true remission occurs.
