Association of prurigo nodularis and lichen simplex chronicus with hospitalization for mental health disorders in US adults.

Prurigo nodularis (PN) and lichen simplex chronicus (LSC) are debilitating chronic pruritic diseases that can lead to and be exacerbated by psychosocial distress. However, little is known about the mental health (MH) comorbidities of PN/LSC. We sought to evaluate the likelihood and cost-burden of MH comorbidities and emergencies associated with PN/LSC. Data were examined from the 2002-2012 Nationwide Inpatient Sample, including a representative ~ 20% sample of US hospitalizations (n = 87,053,155 admissions). Inpatients with vs. without PN/LSC had higher odds of MH disorders overall (39.4% vs. 20.0%; adjusted odds ratio [95% confidence interval, CI] 2.26 [2.13-2.41]) and in all 15 individual MH disorders examined. Inpatients with vs. without PN/LSC were more likely to be admitted with a primary diagnosis of a MH disorder (4.5% vs. 2.2%; 2.16 [1.91-2.45]), particularly developmental, psychotic, and mood disorders, history of MH disorders or substance abuse, and cognitive disorders. PN/LSC were associated with prolonged inpatient length of stay, and an excess $0.69 million in inpatient costs of care indirectly related to hospitalization for MH disorders. In conclusion, inpatients with PN/LSC had increased likelihood of comorbid MH disorders and emergencies requiring hospitalization. Optimized approaches are needed for screening and managing MH comorbidities in PN/LSC.