Oral therapy for rosacea

Journal of Drugs in Dermatology, Jan, 2006 by Hilary E. Baldwin

Abstract

This article will examine oral therapies utilized in the treatment of rosacea. Important topics include recognizing which types of rosacea can benefit from oral therapy and concerns regarding the emergence of bacterial resistance.

Introduction

Rosacea is a common disorder affecting 13 to 14 million people in the US alone. (1,2) Despite earlier beliefs that rosacea was primarily a disease of light-skinned Caucasian women, we now know that it affects all races. Erythema may be more difficult to appreciate in patients with skin types IV and V, but papules, pustules, and granulomatous lesions are commonly seen. Although women may have a higher incidence of rosacea than men, men are more likely to develop phymas. The diagnosis is most often made in patients in their 30s to 50s. (3)

The preceding is a statement of the clinical features of rosacea. However, to truly understand the impact of rosacea on the 13 to 14 million sufferers, the psychosocial impact cannot be overlooked. For many of our patients, the stigma of a "rum blossom" or "drinker's nose" and the social and professional isolation that results from low self-esteem and prejudice is far more significant than the clinical reality.

In part resulting from our poor understanding of the pathogenesis of this condition, we don't truly treat rosacea, but rather manage it. We cannot offer patients cures, simply improvements. As with all incurable conditions, frustrations with inadequate therapy and chronicity of therapy plagues rosacea treatment plans. Benefits from a combination of both medical and psychological approaches cannot be overemphasized. The overall goal is the improvement of the quality of life of the patient. No two patients will be alike in their needs in this regard.

Classification of Rosacea

Rosacea is a condition characterized by a constellation of findings including central facial erythema and telangiectasias, papules and pustules, granulomatous nodules, phyma formation, and ocular changes. The disorder is capricious with flares and remissions that appear to have no rationale.

For the task of discussing therapy, rosacea is best viewed as a collection of several conditions with a common name. Although many patients have polymorphic disease, most have one feature that predominates. It is likely that as we gain knowledge of the pathogenesis of rosacea it will no longer be considered a single entity but rather several conditions that may or may not co-exist. It is unlikely, for example, that the formation of phymas and the etiology of flushing have a single common pathophysiologic factor. Certainly their therapeutic approach is markedly different.

Historically, rosacea was described as occurring in 4 stages from pre-rosacea, (flushing and blushing) through severe inflammatory lesions, persistent erythema, and phyma formation. (2,4,5,6) This classification system implied gradual progression from pre-rosacea to advanced disease, a clinical course that is uncommonly seen. Clinical trials were hampered by a lack of standardized criteria.

A more useful classification system based on predominant lesion morphology was developed by a committee of the National Rosacea Society and published in 2002. (7) In this system, patients are classified as having one of 4 types: erythematotelangiectatic, papulopustular, phymatous, or ocular with a variant form referred to as granulomatous. Individual patients may straddle one or more subtypes, but this system allows us to evaluate therapy based on similar lesion types. Therapeutic options for the various types are easily categorized and there are few medications or therapies that are significantly effective in more than one category.

Pathophysiology of Rosacea

It is widely recognized that therapeutic options in disease should logically be based on clear pathophysiologic understanding of the condition at hand. Our lack of understanding regarding the etiology of rosacea hampers our therapeutic efforts. Still unclear at this time are such fundamental issues as whether or not the papules and pustules are follicular based and what role, if any P. acnes and other organisms play in the development of these inflammatory lesions. The neurologic or hormonal mechanisms that may generate the flushing reaction and phyma formation are similarly unknown. It is unclear if accumulated sun damage plays a role in the etiology of erythematotelangiectatic rosacea to which it bears many biochemical and clinical similarities.

What is known is that inflammation plays an important role in lesion formation. Inflammatory cells release proinflammatory mediators and degradative enzymes that damage dermal constituents. (8)

The outcome of our poor understanding of the pathogenesis of rosacea is that treatment is based on disease endpoints rather than targeting the underlying anomalies. Inflammation is treated with anti-inflammatory agents, flushing with vasoconstrictors, telangiectasias with vascular lasers and pustules treated with antibiotics without a target organism.