Comorbidities and inpatient mortality for pemphigus in the U.S.A.

Background: The morbidity and mortality associated with pemphigus and its treatments have not been fully described. Previous studies have found conflicting results about certain comorbidities and were limited by small sample sizes. Objectives: To determine the morbidity and mortality from pemphigus and its treatments in the U.S.A. Methods: We examined a cross-sectional cohort of 87 039 711 hospitalized patients in the U.S.A. to determine the inpatient comorbidities and mortality of pemphigus. Results: In multivariate survey logistic regression models adjusting for age, sex and race/ethnicity, pemphigus and its treatments were associated with 39 of 122 comorbidities examined. The disorders most strongly associated with pemphigus were Cushing syndrome [adjusted odds ratio (OR) 17·23, 95% confidence interval (CI) 2·41–122·90], adrenal insufficiency (4·08, 1·71–9·73), myasthenia gravis (6·92, 2·55–18·79), mucositis (17·19, 7·73–38·22), herpes infection (7·98, 3·62–17·62), fungal infections (4·03, 3·60–4·52), insomnia (18·02, 2·46–131·88) and hidradenitis (5·34, 1·33–21·43). Among malignancies, only leukaemia (OR 1·56, 95% CI 1·08–2·24) and non-Hodgkin lymphoma (1·52, 1·15–2·03) were associated with pemphigus, but not any solid organ malignancies. Patients with a secondary diagnosis of pemphigus had higher inpatient mortality (3·20%, 95% CI 2·71–3·69) than those with a primary (1·60%, 1·29–1·91) or no (1·78%, 1·78–1·78) diagnosis of pemphigus (P < 0·001). Conclusions: Pemphigus is associated with increased inpatient mortality, likely through its association with numerous comorbid health conditions. Patients with pemphigus require improved access to dermatological care and increased screening for the myriad of comorbidities.