Study Evaluates Prevalence of 4 Major Rosacea Subtypes

Yousef Barakjii, MS

A new systematic review into a variety of rosacea subtypes found erythematotelangiectatic and papulopustular rosacea were among the most prevalent subtypes. Differences in rosacea subtypes were also observed regarding patient sex, continent of origin, and the year of publication.

In 2002, the National Rosacea Society established a classification system for rosacea that was based on 1 primary feature such as transient or persistent erythema, inflammatory papules or pustules, or telangiectasia.

Further classification would involve 4 subtypes including erythematotelangiectatic rosacea (ETR), papulopustular rosacea (PPR), phymatous rosacea (PhR), and ocular rosacea.

The system was updated in 2017 and replaced with a phenotype-based approach to diagnosis, which was later adopted by the National Rosacea Society Expert Committee.

Investigators led by Yousef Barakjii, MS, Bispebjerg Hospital, University of Copenhagen, utilized this system in their systematic review and meta-analysis of published literature to examine the frequency of the 4 major subtypes of rosacea.

Rønnstad and colleagues utilized PubMed and Embase to search for all relevant articles regarding rosacea from data-base inception to November 2, 2021.

Additionally, the Newcastle-Ottawa scale (NOS) was used to assess the quality of eligible studies in the analysis, with a NOS score of 6 or higher indicating high quality. All studies were included regardless of their NOS score.

From there, studies were divided into 3 groups, with the proportion of rosacea subtypes being determined for each one. No restrictions were issued regarding study design, but eligible studies were required to be original and include absolute numbers or frequency of patients affected by the rosacea subtypes.

The search ended with a total 9732 articles, 6219 of which were from Embase and 3513 that originated from PubMed. Following removal of duplicates, a total of 102 articles were included in the qualitative analyses, with 97 containing data for the quantitative analysis.

Among these articles, 39 studies reported all 4 subtypes of rosacea, and a total of 140,458 patients with rosacea were included in the analysis.

Investigators noted that the ages of the patients ranged from 8-95 years, and that it was not possible to provide a mean or median. Despite this, most studies reported a mean age of approximately 50 years.

The team observed that the pooled proportion of erythematotelangiectatic rosacea was 56.7% (95% CI, 51.4%-62.0%), followed by papulopustular rosacea at 43.2% (95% CI, 38.8%-47.6%), phymatous rosacea at 7.4% (95% CI, 6.1%-8.9%), and ocular rosacea was 11.1% (95% CI, 6.7%-16.3%).

Subtype distribution was equal among men and women, with the exception of phymatous rosacea, which was more prevalent in men.

Notably, studies from Africa- 4 in total- featured the lowest proportion of erythematotelangiectatic rosacea, and further differences in frequency of subtypes were observed when stratification by publication year was performed.

Despite the suggestions that the data presented regarding common subtypes of rosacea, investigators emphasized caution due to the high degree of heterogeneity.

“Better and more detailed reporting is warranted in future studies to allow for new and improved insight into subtypes and their possible association with clinical characteristics and comorbidities,” the team wrote. “We also strongly recommend that future studies use the phenotype-based approach to diagnose and report rosacea.”

The study, "Assessment of Frequency of Rosacea Subtypes in Patients With RosaceaA Systematic Review and Meta-analysis," was published online in JAMA Dermatology.