INTRODUCTION
Rosacea is a common facial disorder affecting approximately
16 million people in the United States.1 The
facial skin of patients with rosacea is characterized by
persistent erythema, visible blood vessels and often papules
and pustules.2 Rosacea sufferers frequently experience skin
sensitivity characterized by physical discomfort, burning sensation,
facial itching, stinging and swelling.3 The lactic acid test
involving application of a solution of lactic acid to the skin and
assessing the subject's reaction is a validated test for determining
skin sensitivity. Approximately 75 percent of patients with
rosacea have a positive reaction to this test compared with <20
percent of normal subjects,4 demonstrating the prevalence of
sensitive skin among rosacea sufferers. There are four main
subtypes of rosacea: erythematotelangiectactic, papulopustular,
phymatous and ocular.5 Available topical treatments are
indicated for the treatment of papules, pustules and erythema.6
Topical medications comprise a major component of therapy for
papulopustular rosacea. Currently, only one oral medication is
approved by the Food and Drug Administration for the treatment
of papulopustular rosacea, a subantimicrobial dose of doxycycline
(Oracea®). In contrast, there are many topical medications
to choose from that vary in active ingredient and vehicle, providing
dermatologists with a wide array of treatment options.
Ideally, treatment should not only deliver the active ingredient
to its site of action but should not further irritate the skin, and
medications that are potentially acnegenic should be avoided.
Formulations that calm and soothe the skin are preferable. Emollient
and barrier repair ingredients are important, as these may
help repair inherent barrier dysfunction.
Other features that are important when choosing a therapy are
its ease of application and its effect on the appearance of the skin
when used with the patients' regular skin care routines, particularly
the application of cosmetics. The ease of application and
appearance of both the medication and patients' usual cosmetic
regimens have been shown to influence patients' ratings of their
overall appearance.7 Ideally, topical therapies should be well tolerated
on oily and/or dry skin, as many patients display findings
of both. A vehicle that is tolerated on both skin types allows for
more flexibility of application.
It has been suggested that the vehicle of a topical therapy may
account for 50 percent to 75 percent of its efficacy.8 A vehicle
must allow penetration of the active ingredient, without damaging
the skin barrier. It must deliver the correct dose, while being
easy to use and well tolerated. This review will focus on commonly
used topical therapies for papulopustular rosacea and the
key components of their respective vehicles that influence the
delivery of the active ingredient and repair of the skin barrier,
and maximize tolerability. How these formulations are accepted
in clinical practice will also be discussed.
Topical Rosacea Treatments and Their Vehicles
Three main active ingredients are found in topical rosacea
therapies: metronidazole, azelaic acid, or sodium sulfacetamide-
