Treating Inflammation in Rosacea: Current Options and Unmet Needs

June 2020 | Volume 19 | Issue 6 | Original Article | 585 | Copyright © June 2020


Published online May 21, 2020

Jerry Tan , J. Mark Jackson

aDept of Medicine, Western University, London, Ontario, Canada bUniversity of Louisville, Division of Dermatology, Forefront Dermatology, Louisville, KY

Abstract
Rosacea is a disease resulting from dysregulation of innate, adaptive, and neurovascular immune systems. Inflammatory pathways activated in rosacea can explain many of its signs and symptoms. Current treatments address some of these inflammatory processes, alleviating erythema and decreasing papules and pustules. However, for the majority of patients, complete clearance of these features is not currently achievable even with combination therapy. There is a need to address the spectrum of inflammatory processes involved in rosacea and for more efficacious agents with the goal of providing complete clearance for patients.

J Drugs Dermatol. 2020;19(6): doi:10.36849/JDD.2020.5187

INTRODUCTION

Rosacea has been described in the medical literature for centuries.1 Twentieth-century medical publications referred to multiple phases of rosacea, typically asserting its pathophysiology as “unknown.”2 In 2002, the National Rosacea Society Expert Committee described the primary and secondary features for rosacea diagnosis and classified four presentation patterns as subtypes: erythematotelangiectatic (ETR), papulopustular (PPR), ocular, and phymatous.3 However, each subtype contained multiple signs and symptoms, most of which overlapped with one or more other subtypes and did not account for variation in individual patient presentation.4 This led to confusion in epidemiological studies, clinical trial patient recruitment, and the development of assessment scales conflated to measure divergent features (eg, erythema and papules/pustules) that did not necessarily respond to interventions in parallel.4 Consequently, in 2017 a global panel of rosacea experts updated the diagnostic criteria for rosacea based on clinical features, termed the phenotype approach (Table 1).5,6

Many recent reviews point to advances in understanding the pathogenesis of rosacea as prompting this shift in the description of rosacea—notably, that most cases seem attributable to aberrations in the immune system.6,7

This review discusses the underlying inflammatory nature of rosacea, treatments that target these inflammatory processes, and shortcomings of current therapies.

Inflammation in Rosacea
The pathophysiology of rosacea involves the innate and adaptive immune systems, as well as neurovascular dysregulation. External and endogenous triggers initiate and aggravate various pathways in rosacea patients (Figure 1).