Publication trends in hidradenitis suppurativa from 2008 to 2018

Increased interest in hidradenitis suppurativa (HS) research is encouraging. A critical analysis of the state of HS literature may demonstrate the strength of existing knowledge and highlight current gaps.

To analyse changes in HS literature from 2008 to 2018 with focus on quantity and quality of annual publications.

Review of all indexed publications reporting on HS on PubMed. Publications were categorized based on study design, study topic and treatment type where applicable. Publications were dichotomized into high level of evidence and low level of evidence groups. Linear regression analyses were performed to investigate the change in publication number over time. Annual average growth rate and distribution of high versus low level of evidence publications were calculated.

Publication number increased over time overall (R²  = 0.64, P = 0.003) and for all publication types except randomized clinical trials. Case reports and case series represented the majority of HS publications (n = 479, 40.3%). Treatment was the main focus of publications (n = 445, 37.6%) with increasing interest in medical management evident in recent years. Distribution of low level of evidence studies (n = 974) compared with high level of evidence studies over time (n = 209) was significant (x² : 11.45, P = 0.0007). High level of evidence studies had a higher average annual growth rate (49.9%) compared with low level of evidence studies (23.7%). Few randomized clinical trials were performed (n = 16), focusing equally on medical or procedural treatments.

Hidradenitis suppurativa research is undergoing a tremendous shift, suggesting rapid maturation of the field. Current HS literature, however, remains primarily based on limited clinical observation data, with a particular lack of randomized clinical trials. Despite this, the increase in high level of evidence studies is encouraging and may herald a shift towards improved disease understanding and treatment paradigms.