Cutaneous involvement in localized forms of bullous pemphigoid.

In summary, there is much overlap among the three types of localized cutaneous pemphigoid discussed. They all tend to affect the same age group, in general. They all may remain regional or be associated with a generalized eruption consistent with bullous pemphigoid. These three variants of subepidermal blistering disease also appear to be susceptible to koebnerization. Direct immunofluorescence findings are identical, as well, with linear IgG and C3 at the basement membrane. Indirect immunofluorescence tends to be negative for all three variants, with a tendency to positivity with increased extent and severity of skin involvement. There are differences, though, between them. BPP tends to affect men more than women, unlike BMMP-CP and localized cutaneous nonscarring BP. Localized cutaneous nonscarring BP usually involves the legs, whereas the other two conditions affect the head and neck, with resultant scarring. Histology is similar to that seen in BP, but dermal fibrosis and sclerosis result in skin affected by BMMP-CP and BPP. Localized cutaneous nonscarring BP is more amenable to topical steroid therapy, whereas BMMP-CP and BPP are more persistent and resistant to systemic immunosuppressive therapy. Clinical, histologic, and immunologic similarities among the pemphigoid variants may reflect common antigenic features. On the other hand, clinical, histologic, and immunologic differences may imply that there are more than one bullous pemphigoid antibody directed at a variety of antigenic structures.