Management of rosacea

Pharmacist counseled patient on topical metronidazole for rosacea and I was unaware of this indication for this drug, so I researched more about it -->

Rosacea:

• Chronic and relapsing inflammatory skin disorder
• Clinical features: 4 subtypes
• Erthematotelangiectatic: transient erythema, inflammatory skin lesions, telangiectasias (tiny blood vessel pattern on skin), dry/scaly
• Papulopustular: inflammatory papules and pustules, persistent erythema
• Phymatous: skin hypertrophy resulting in disfigurement
• Ocular: conjunctivities, blepharitis, chalazion, stye formation
• features of multiple types may occur spontaneously
• Management:
• Avoidance of flushing triggers (alcohol, sunlight, stressors, extreme temperatures)
• frequent moisturizing
• gentle cleansing
• avoid irritating topical products (toners, exfoliation
• Pharmacological management:
• Erthematotelangiectatic: topical brimonidine gel
• vasoconstrictive alpha 2 adrenergic receptor agonist
• Papulopustular
• Mild-moderate: 
• topical metronidazole - mechanism unknown, improvement may occur after 2-4 weeks of therapy, full results at 8-9 weeks, relapse may occur after discontinuation --> may need long-term therapy
• topical azelaic acid - dicarboxylic acid with anti-inflammatory properties, available as cream, foam or gel, improvement may be seen within 2 weeks but full results at 12-15 weeks, may cause skin irritation (avoid in sensitive skin)
• topical ivermectin 1% cream - anti-inflammatory and anti-parasitic, well-tolerated, may use for up to 1 year
• other therapies (not first-line): topical permethrin, topical retinoids, topical clindamycin, benzoyl peroxide, sulfacetamide-sulfur
• Moderate-severe:
• oral tetracyclines (tetracycline, doxycycline, minocycline): due to anti-inflammatory properties (not anti-microbial)
• doxy or mino 50-100 mg BID or tetracycline 200-250 mg BID for 4-12 weeks
• do not give to children < 9 yeras old (reduced bone growth, tooth discoloration)
• may have occasional break-through flares that can be treated with short-courses of therapy.
• may combine with topical metronidazole
• alternatives: macrolide antibiotics (clarithromycin, azithromycin, erythromycin), oral metronidazole
• Refractory: 
• oral isotretinoin -- teratogenic, need to be prescribed through iPLEDGE program, 0.5-1 mg/kg/day for 5-6 months
• laser/light therapy
• Ocular: 
• topical and oral antibiotics (metronidazole, tetracyline, erythromycin)
• topical cyclosporine
• Phymatous:
• isotretinion 0.3-1 mg/kg/day for 12-28 weeks
• laser ablation, surgical interventions
• Pediatric - treat similar to adults but avoid tetracyclines

References: Maier L. Management of rosacea. UpToDate. Dahl M (Ed). Last updated: 14 June 2016. Accessed on: 8 November 2016.