Bullous pemphigoid: the frequency of mucosal involvement and concurrent malignancy related to indirect immunofluorescence findings.

A review of 124 cases of bullous pemphigoid was made and the clinical findings correlated with the results of indirect immunofluorescence. A circulating IgG basement membrane zone (BMZ) antibody was detected in the serum of eighty-nine (72%) of the patients. Antibody titres in these patients did not correlate with the extent of the disease or with the presence of mucous membrane lesions. Indeed, oral lesions were more common in the thirty-five sero-negative patients with 17% of such patients being affected compared to only 10% of those with positive indirect immunofluorescence findings. This difference, however, was not statistically significant. Concurrent malignant disease (i.e. malignancy occurring within 6 months of pemphigoid being diagnosed) occurred in eight of the seronegative group (23%) and in only four of the eighty-nine seropositive cases (4%); this difference was significant. The association of bullous pemphigoid and malignant disease still remains controversial, but those who believe that the relationship is coincidental must now explain why concurrent malignant disease is more common in patients who have bullous pemphigoid and negative indirect immunofluorescence findings.