Rosacea Diagnosis and Subtypes

The classification of rosacea into subtypes by the NRS 'expert' committee in 2002 has been controversial from the beginning. The ROSCO panel has taken the classification of rosacea in a new direction, classifying rosacea into phenotypes. The RRDi has endorsed this new classification of rosacea into phenotypes. While published papers continue to refer to subtypes, these clinicians are simply not keeping up with the state of the art classification of rosacea into phenotypes. [1]

What is the difference between a phenotype and a subtype? Answer. Why is the classification into phenotypes superior to subtypes? Answer. 

For those who are not acquainted with the old subtype classification of rosacea may need a basic understanding of diagnosing rosacea. 

Diagnosing Rosacea into Subtypes

There are no clinical, serological or other diagnostic tests for rosacea. A diagnosis of rosacea is simply arrived through taking a patient history and a physical examination by a physician which may include some tests to rule out other skin conditions that mimic rosacea. There have been proposed a number of rosacea subtypes by various authorities. The RRDi lists at least five (with some other proposed subtypes in consideration):

Subtype 1
Erythematotelangiectatic Rosacea

Subtype 2
Papulopustular (Papules & Pustules)

Subtype 3
Phymatous (rhinophyma [red, enlarged nose])

Subtype 4
Ocular (red, dry or gritty eyes)

Subtype 5
Neurogenic Rosacea

The classification of rosacea into subtypes is controversial. Click here for more info.

Phentotypes vs Subtypes

ROSCO Panel Recommends New Approach on Rosacea Diagnosis by Phenotype

Other Proposed Subtypes
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End Notes 

[1] For example, note what this published paper (April 2022) says regarding subtypes: 

"Four distinct rosacea subtypes have traditionally been recognized, but the frequency of these subtypes among patients with rosacea remains unknown."
Assessment of Frequency of Rosacea Subtypes in Patients With Rosacea: A Systematic Review and Meta-analysis