Advances in the topical treatment of acne and rosacea

Journal of Drugs in Dermatology, Sept-Oct, 2004 by Roger I. Ceilley

The first stage of rosacea is vascular and consists of erythema. Flushing reactions are due to trigger factors such as temperature extremes, wind, alcohol, and leads to increased blood flow through the dermis. Extracellular fluid accumulates faster than the lymphatics can drain it (31). In the setting of this lymphatic failure, plasma protein exudates accumulate and produce a self-sustaining inflammation. These plasma proteins may also play a role in the fibroplasia which is characteristic of later stages of the disease (32,33). As the rosacea progresses, continued inflammation leads to the release of cytokines and other inflammatory mediators as well as enzymes, such as neutrophil elastase, which can degrade elastin and collagen. This leads to reduced capillary wall integrity and the sustained accumulation of extravascular fluids. Elastin degradation is also the result of photodamage which is commonly encountered in the typical rosacea-prone phenotype. The telangiectatic phase of rosacea may be due to actinic damage and angiogenesis as well as the disruption of the mechanical integrity of the superficial dermal connective tissue, allowing the passive dilation of blood vessels (31,34). The issue of whether or not Demodex folliculorum overgrowth is present and whether an immunologic response to the mites or their products contribute to the inflammation of rosacea is an ongoing controversy. Likewise, the role of H. pylori infection is controversial (30).

New Standard Classification of Rosacea: Subtypes of Rosacea

In 2002, an expert committee within the National Rosacea Society developed a new classification system for rosacea, aimed at simplifying diagnosis and facilitating the sharing of information among physicians, patients, researchers and insurers.

Guidelines for Diagnosis: The committee developed guidelines for the diagnosis of rosacea that require the presence of one or more primary features. One or more secondary features must also be present (Table 3) (35).

The primary rosacea features include flushing (transient erythema), nontransient erythema or persistent redness of the central face, which is the most common sign of rosacea. Papules and pustules, which often appear in clusters, and telangiectasia are also considered primary features.

The secondary features, which are not required for diagnosis, frequently appear in combination with one or more of the primary features or may appear on their own. They are: burning or stinging, plaques, dryness resembling xerosis, edema often in concert with prolonged flushing, ocular manifestations, peripheral location and phymatous changes, typically rhinophyma.

The new classification system also identifies subtypes of rosacea. These are clusters of primary and secondary rosacea features that often occur together. Subtype 1 is erythematote-langiectatic rosacea. Subtype 2 is papulopustular rosacea. Subtype 3 is phymatous rosacea and Subtype 4 is ocular rosacea (Table 4) (35).

Diagnosis of Rosacea

There are no laboratory tests or clinical markers to verify a diagnosis of rosacea. Observation and history-taking are the two most important diagnostic tools in rosacea (Table 5).