Associations of cutaneous and extracutaneous infections with hidradenitis suppurativa in U.S. children and adults.

Background: Hidradenitis suppurativa (HS) is associated with bacterial colonization, skin-barrier disruption, immune dysregulation and treatments that can increase infection risk.

Objectives: To determine whether HS is associated with cutaneous and extracutaneous infections and related outcomes.

Methods: Data from the 2002-2012 National Inpatient Sample were analysed, including a 20% sample of U.S. hospitalizations (n = 87 053 155).

Results: The prevalence (with 95% confidence interval) of infections was higher in adults (34·0%, 33·2-34·7% vs. 23·4%, 23·2-23·6%) and children (31·8%, 28·7-34·9% vs. 12·6% (12·1-13·1%) with vs. without HS. Inpatients with HS had higher prevalences of infections overall (excluding cellulitis and erysipelas) than those with psoriasis, but lower than those with atopic dermatitis. In multivariable logistic regression models adjusting for sociodemographics, HS was associated with 18 of 45 infections examined (adults: 16 of 45; children: six of 45), including acute infections (herpes simplex virus, herpes zoster, necrotizing fasciitis, septicaemia, bone infection, Clostridium difficile, methicillin-sensitive and methicillin-resistant Staphylococcus aureus, Streptococcus, Pseudomonas, mycobacterial, fungal, viral), chronic infections (HIV, hepatitis B) and antibiotic-resistant infections. HS alone was associated with increased infections. Patients with comorbid cancer; HIV; cardiometabolic, autoimmune or mental health diagnoses or acne had even higher odds of infections. Inpatients with HS with vs. without serious infection had increased inpatient mortality (0·71% vs. 0·16%), mean length of stay (7·3 vs. 4·8 days) and cost of care (US$13 578 vs. $9242), with a mean annual excess 41 050 days and $71 622 339 cost of hospitalization.

Conclusions: Adults and children with HS had increased acute and chronic, cutaneous, extracutaneous and systemic infections, which were associated with increased mortality and cost. What's already known about this topic? Little is known about the risk of infection in patients with hidradenitis suppurativa (HS). What does this study add? Adults and children with HS had increased cutaneous, extracutaneous and systemic infections, at even higher rates than in patients with psoriasis and atopic dermatitis. These infections were associated with increased inpatient mortality and cost. Respond to this article.