Comorbid diseases among bullous pemphigoid patients in Germany: new insights from a case-control study

Bullous pemphigoid (BP) is associated with neuropsychiatric disorders. Other comorbid diseases are discussed controversially. We evaluated the prevalence of comorbidity in BP patients in a representative area of Germany.

Medical files of all BP patients treated at the Department of Dermatology, University Hospital Würzburg, Germany, between June 2002 and May 2013 were retrospectively reviewed. Bullous pemphigoid was diagnosed based on established criteria. For each patient, two controls were individually matched. Records were evaluated for age, sex, laboratory values, concomitant medication and comorbidity. Conditional logistic regression, multivariable regression analysis and complex regression models were performed to compare results.

300 BP patients were identified and compared to 583 controls. Bullous pemphigoid was associated with neuropsychiatric disorders as well as laboratory abnormalities including leukocytosis and eosinophilia. Importantly, a highly significant association of BP with anemia (OR 2.127; 95 % CI 1.532-2.953) and renal impairment (OR 2.218; 95 % CI 1.643-2.993) was identified. No association was found with malignancy and arterial hypertension.

Our data revealed an increased frequency of anemia and renal impairment in BP patients. In accordance with previous studies the strong association for neuropsychiatric disorders was confirmed (p < 0.0005).