Prognostic factors of paraneoplastic pemphigus.

Objective: To identify the prognostic factors of overall survival in a series of patients with paraneoplastic pemphigus (PNP).
Design: Multicenter retrospective cohort study.
Setting: Twenty-seven dermatology departments in France.
Patients: A total of 53 patients (31 men and 22 women; median age, 59 years; age range, 30-88 years) were diagnosed as having PNP between 1992 and 2010.
Main Outcome Measures: Overall Kaplan-Meier survival rates were estimated, and features associated with survival were assessed using univariate (log-rank test) and multivariate (Cox regression) analyses.
Results: The study included 53 patients with PNP. Thirty-six patients (68%) died during the study. The 1-, 3-, and 5-year overall survival rates were 49%, 41%, and 38%, respectively. The main causes of death were infections (n=21) and evolution of neoplasia (n=6). In univariate analysis, the main detrimental prognostic factors identified were erythema multiforme–like skin lesions (P=.05) and histologic keratinocyte necrosis (P=.03). None of the 5 patients with Castleman disease died during the study. After adjustment for age and sex in multivariate analysis, erythema multiforme–like skin lesions remained predictive of fatal outcome, with a 2-fold increase in death rate (hazard ratio [HR], 2.3; 95% CI, 1.05-5.03; P=.04). The prognosis of patients with PNP was even poorer when erythema multiforme–like skin lesions were associated with severe skin or mucosal involvement at presentation (HR of death, 3.0; 95% CI, 1.01-8.92; P=.049).
Conclusion: Patients with PNP with erythema multiforme–like skin lesions and histologic keratinocyte necrosis, especially when associated with extensive lesions at presentation, are likely to have a more severe and rapid fatal outcome and should be managed very carefully.