Clinical presentation and diagnostic delay in bullous pemphigoid: a prospective nationwide cohort

Background Prospective systematic analyses of the clinical presentation of bullous pemphigoid (BP) are lacking. Little is known about the time required for its diagnosis. Knowledge of the disease spectrum is important for diagnosis, management and inclusion of patients in therapeutic trials. Objectives The primary aims of the study were: (i) to characterize the clinical features of BP at time of diagnosis; and (ii) to assess the diagnostic delay in BP and its impact on prognosis Methods All new cases of BP diagnosed in Switzerland between 1 January 2001 and 31 December 2002 were prospectively registered by means of a standardized data collection form. Results One hundred-seventeen patients with BP were included in the study. 97cases (82.9%) had typical features with vesicles, blisters and/or erosions at time of diagnosis, while in the remaining cases (17.1%) only excoriations, eczematous and/or urticarial infiltrated lesions were observed. Head/neck as well as palmo-plantar involvement were found in up to 20% of patients, while mucosal lesions were present in 14.5% of the cases. Diagnosis was made after a mean of 6.1 months after the first symptoms. In patients, in whom the diagnostic delay was 4 months or more (defined as late diagnosis group), lesions were more often limited to one body area. The type of lesions did not affect the diagnostic delay. Diagnosis was made more rapidly in patients with limb involvement compared to those without. The calculated mortality rate in the early and late diagnosis group was 18.9% and 17.9%, respectively, without significant difference. Conclusion BP often presents with bullous lesions at time of diagnosis after a mean diagnostic delay of 6 months. Nevertheless, up to 20% of patients lack obvious blistering and postbullous erosions, mimicking thus a variety of inflammatory dermatoses. Localized disease is associated with an increased diagnostic delay, which has however no impact on prognosis.