Therapeutic Update on Rosacea

While the exact etiology of rosacea remains to be elucidated, it is now widely accepted that it is a chronic inflammatory condition that occurs in the context of an altered innate immune response.¹ The current model for rosacea suggests that environmental changes induced by microbes (such as Demodex folliculorum), hormonal shifts, or UV light exposure are detected by pattern recognition receptors of the immune system. Subsequent signaling-induced effector molecules, such as cytokines, cathelicidin, chemokines and reactive oxygen species may then modify dermal structure through vascular changes, lymphohistiocytic infiltration, neutrophil recruitment, and collagen degradation, which may perpetuate this response.^2,3 Most current therapies are aimed at modulating various points of this inflammatory cascade.

Despite the fact that a clear bacterial pathogen has not been implicated in the pathophysiology of rosacea , antibiotics have numerous anti-inflammatory properties which include suppressing neutrophil migration and chemotaxis, inhibiting angiogenesis, blocking the production of matrix metalloproteinases (MMPs), inhibiting the activation, proliferation and migration of lymphocytes and upregulating anti-inflammatory cytokines.^5,6

The most common systemic drugs include doxycycline, erythromycin, minocycine, tetracycline, metronidazole, and occasional off-label low-dose isotretinoin.⁷ Subantimicrobial low-dose oral doxycycline has been shown to be effective with less risk of affecting endogenous flora and lower chance of development of antibiotic resistant strains.⁸

The most common topical medications include azelaic acid, metronidazale, erythromycin, or sodium sulfacetamide 10% and sulfur 5%.⁹ Recently, pimecrolimus 1% cream has been found to be effective for mild to moderate inflammatory rosacea.^10,11

Choice of vehicle (lotion, cream, gel foam) can influence tolerability in patients who often have heightened skin sensitivity.

Many rosacea patients who perceive their skin as sensitive may also try herbal and botanical “natural” remedies, such as feverfew, turmeric, colloidal oatmeal, niacinamide and quassia extract.^12,13 In addition, other alternative therapies, such as colloidal silver, emu oil, laurelwood, oregano oil and vitamin K have been promoted as possible ways to treat rosacea.¹⁴ While many of the ingredients show promise, there is a paucity of data regarding the effects of these cosmeceuticals and further studies are warranted.

Both the pulsed dye laser and intense pulsed light treatments have been found to be effective at reducing the erythema of rosacea by selectively targeting the red hemoglobin pigment in blood vessels, thermally coagulating blood, and destroying the blood vessel walls without damaging the overlying skin.^15,16

Avoidance of triggers (hot, cold, wind, sun exposure, emotional issues), dietary changes (spicy foods, alcohol), use of daily sunscreen, gentle cleansers and proper skin care are also necessary measures in controlling rosacea.^17,18 Concealing cosmetics that can counteract the redness (such as green-tinted emollients) are useful adjuncts in improving quality of life and self-esteem in the management of this chronic condition.

The alpha adrenergic agonists brimonidine tartrate and oxymetazoline are currently found in eye drops for glaucoma and a nasal decongestant spray, respectively.¹⁹ They have potent vasoconstrictive capabilities and anti-redness effects.

Topical brimonidine tartrate, 0.33% gel, an alpha 2 agonist, was approved by the FDA in September 2013, for the treatment of persistent facial erythema of rosacea. In clinical studies, a single application of the 0.5% gel reduced erythema up to 12 hours.²⁰

Oxymetazoline, a potent alpha-1 and partial alpha-2 receptor agonist has also shown promise for reducing facial erythema.²¹ A topical form of oxymetazoline is currently being investigated for the treatment of erythematotelangiectatic rosacea.²²