CKS did not identify any authoritative, UK-based guidelines on the management of rosacea. Therefore, recommendations are based on evidence from randomized controlled trials (RCTs) where available [van Zuuren et al, 2005], and otherwise on the best available expert opinion described in narrative reviews [Berth-Jones, 2004; Powell, 2005; Diamantis and Waldorf, 2006].

• A thorough assessment of rosacea is a pragmatic recommendation that reflects the need to rule out other diagnoses (especially acne vulgaris) and accurately determine the predominant subtype of rosacea in order to carry out optimal management. Vasodilatory drugs, such as calcium-channel blockers, should be avoided where possible, as they can exacerbate flushing [Powell, 2005].
• Only papulopustular rosacea is receptive to treatments that are commonly used in primary care, with erythematotelangiectatic rosacea (i.e. persistent redness and flushing) being particularly difficult to treat [Baldwin, 2006]. In one RCT, people with poor outcomes were described as having 'redness rather than pustulation' as the predominant symptom of their rosacea [Pelle et al, 2004].

Topical treatments

• Treatment of papulopustular rosacea is mainly symptomatic in nature, as there is a lack of evidence that treatment improves the underlying pathology or the long-term prognosis of the disorder [Berth-Jones, 2004]. However, treatment can lead to remission in the shorter term, and most drugs can be used intermittently or continuously to control symptoms (see Follow up).
• Metronidazole is usually suitable as first-line treatment for mild-to-moderate papulopustular rosacea and for maintenance of more severe disease [Powell, 2005].
• The mechanism of action of topical metronidazole in rosacea is not fully understood, but it may act as an anti-inflammatory and antioxidant, rather than as an antibiotic [Nally and Berson, 2006].
• There is relatively good evidence from RCTs showing that topical metronidazole is more effective than placebo and equally as effective as oral tetracyclines; it causes fewer adverse effects than azelaic acid [van Zuuren et al, 2005].
• Azelaic acid is an alternative that may be more effective than metronidazole, but is more likely to cause adverse effects [Pelle et al, 2004].
• The mechanism of azelaic acid is likely to be similar to that of metronidazole. Azelaic acid has been shown to be superior to placebo. There is limited evidence from two head-to-head RCTs that azelaic acid is more effective than metronidazole, although further studies are required to confirm if this is clinically relevant [van Zuuren et al, 2005].
• Azelaic acid may cause burning, stinging, itching, scaling, and dry skin in 26–38% of people, although these effects are transient and do not usually affect compliance [Gupta and Gover, 2007].

Oral treatments

• Systemic treatment is recommended when there is moderate-to-severe papulopustular rosacea covering extensive areas that would be difficult to treat topically [Powell, 2005].
• Tetracyclines are effective at a dose that is subtherapeutic to their antibiotic effect; this is thought to be an anti-inflammatory effect [Baldwin, 2006].
• There is limited evidence from RCTs that tetracyclines are more effective than placebo, and as effective as both topical and oral metronidazole [van Zuuren et al, 2005]. The drugs used in these studies were tetracycline and oxytetracycline, which is reflected in their product licenses [BNF 55, 2008].
• Low-dose doxycycline has recently been reported, in two RCTs, to be effective in the treatment of rosacea [Del Rosso et al, 2007], and lymecycline is also likely to be effective. Lymecycline is not licensed for this use in the UK, however, doxycycline 40 mg modified-release capsules have recently been licensed in the UK for rosacea. Both drugs are more convenient to take than the older tetracyclines, an important consideration for a drug that is be used in the long term.
• Erythromycin is an alternative if tetracyclines are contraindicated (e.g. pregnancy, reactions to sunlight), and is recommended on the basis of clinical experience rather than controlled studies [Baldwin, 2006]. However, its effectiveness can be extrapolated from another macrolide, clarithromycin, which has been reported to be more effective, and better tolerated, than doxycycline in one RCT (n = 40) [Pelle et al, 2004].

Ocular rosacea

• Ocular rosacea is the usual cause of posterior blepharitis (Meibomian gland dysfunction), which is discussed fully in the CKS topic on Blepharitis.
• The eye is affected in about half of people with rosacea [Berth-Jones, 2004], and requires treatment to relieve symptoms and prevent deterioration.
• Evidence for the effectiveness of treatment for blepharitis is, in general, lacking. However, CKS identified one RCT (n = 35) that found that oxytetracycline was associated with more remissions than placebo [Bartholomew et al, 1982].