Rosacea

Introduction

Rosacea is a chronic inflammatory condition affecting the central face, typically presenting in adults over 30 and more often diagnosed in women, though the phymatous subtype is more common and more severe in men. It has a relapsing course, with flares often precipitated by identifiable environmental and lifestyle triggers.¹

It is frequently mistaken for acne, sunburn, or simply a 'ruddy complexion', which delays diagnosis and treatment. Because rosacea is chronic and visible, and because flares are often provoked in public or social situations - alcohol, embarrassment, exercise - the psychological impact on confidence and social interaction can be considerable, and is worth asking about directly.²

Pathophysiology

The exact cause of rosacea is not fully understood, but three broad processes are implicated, and most current treatments target one or more of them.

• Vascular dysregulation - an exaggerated flushing response and abnormal dilation of the facial cutaneous vasculature, producing the persistent erythema and telangiectasia
• Innate immune dysregulation - keratinocytes in rosacea-affected skin process the antimicrobial peptide cathelicidin abnormally, generating fragments that are pro-inflammatory and pro-angiogenic, which helps explain both the inflammatory lesions and the vascular changes⁴
• Demodex folliculorum mites - normally commensal in hair follicles, these are found in much higher density in rosacea-affected skin, and may provoke or amplify the inflammatory response, which is the rationale for topical ivermectin

A neurovascular component is also increasingly recognised: the same trigeminal sensory pathways that mediate flushing to heat, spicy food and emotional stress appear to be dysregulated in rosacea, contributing to the intense, disproportionate flushing many patients describe.

Risk factors and triggers

• Fair skin (Fitzpatrick type I-II) and Celtic or Northern European ancestry
• Family history of rosacea
• Female sex for erythematotelangiectatic and papulopustular subtypes; male sex for phymatous disease, which tends to be more severe
• Sun exposure - a major trigger and driver of chronic vascular damage
• Alcohol, particularly red wine
• Hot drinks and spicy food
• Extremes of temperature, hot baths, and vigorous exercise
• Emotional stress

Clinical features

Rosacea affects the central face - the cheeks, nose, chin and forehead - and typically spares the periocular skin. Four overlapping patterns are described.

Flushing is often the earliest symptom, preceding fixed erythema by months to years. Patients frequently report a burning or stinging sensation on the face, particularly with sun exposure, heat or topical products, which can make cosmetic and skincare use difficult and adds to the impact on daily life.

Clinical examination

• Distribution - centrofacial, sparing the periocular skin, versus the wider distribution of acne which can involve the chest and back
• Vascular changes - persistent erythema and visible telangiectasia, best seen in good light
• Inflammatory lesions - papules and pustules, and specifically the absence of comedones
• Phymatous change - thickened, irregular skin, most often examined on the nose
• Eyes - lid margin telangiectasia, blepharitis, conjunctival injection, and any corneal changes, which should prompt ophthalmology referral

Differential diagnosis

• Acne vulgaris - comedones are present, and the distribution extends beyond the central face to the chest and back
• Systemic lupus erythematosus (malar rash) - a butterfly-shaped erythema over the cheeks and nasal bridge that classically spares the nasolabial folds, without the telangiectasia, papules or pustules of rosacea, and accompanied by other systemic features
• Seborrhoeic dermatitis - greasy scale affecting the nasolabial folds, eyebrows and scalp, which can coexist with rosacea and confuse the picture
• Perioral dermatitis - grouped papules and pustules around the mouth with a clear rim of sparing at the vermilion border, often related to topical corticosteroid use
• Contact dermatitis or photosensitivity reaction - a clear temporal relationship to a new product or medication, and a distribution matching the exposure
• Carcinoid syndrome - episodic flushing with diarrhoea and wheeze should prompt consideration of this rare cause rather than simple rosacea-related flushing

Investigations

Rosacea is a clinical diagnosis. Investigations are used only to exclude an alternative cause when the presentation is atypical.

• Antinuclear antibody (ANA) - if the distribution or accompanying features raise concern for lupus
• Skin biopsy - rarely needed, reserved for atypical or diagnostically uncertain presentations
• Referral to ophthalmology with slit-lamp examination - for any ocular symptoms, to assess for blepharitis, keratitis or other corneal involvement

Management

Management combines general skin care measures with treatment targeted at the dominant subtype present.⁵

General measures for everyone

• Daily broad-spectrum sun protection - sunscreen (SPF 30 or higher) is one of the most effective and evidence-based measures available
• Identify and avoid personal triggers - using a symptom diary where the pattern is unclear
• Gentle, fragrance-free skincare - avoiding astringents, exfoliants and alcohol-based products that can irritate sensitive rosacea skin
• Camouflage make-up - green-tinted correctors can reduce the visibility of erythema and help patients who find the appearance distressing

Erythema and telangiectasia

• Topical brimonidine - an alpha-2 agonist that produces short-term vasoconstriction and reduces visible erythema for several hours; does not treat inflammatory lesions
• Vascular laser or intense pulsed light therapy - effective for persistent telangiectasia and background erythema not responding to topical treatment, delivered in a specialist setting

Papulopustular disease

• Topical metronidazole or azelaic acid - first-line for mild-to-moderate papulopustular rosacea⁶
• Topical ivermectin - targets Demodex mite density as well as inflammation, and is an effective alternative first-line option
• Oral tetracyclines (doxycycline, often at a low, sub-antimicrobial anti-inflammatory dose) - for moderate-to-severe papulopustular disease, or where topical treatment alone is insufficient; erythromycin is the alternative in pregnancy or childhood
• Isotretinoin (low dose) - reserved for severe, resistant papulopustular or phymatous disease under specialist supervision

Phymatous disease

Established phymatous change (rhinophyma and its equivalents elsewhere) does not respond well to topical or oral medical treatment, since it reflects fixed tissue overgrowth rather than active inflammation alone. Surgical debulking, laser ablation or electrosurgery are used to restore normal contour once the phyma is established, and are considered earlier if disfigurement is affecting the patient significantly.

Ocular rosacea

Managed jointly with ophthalmology: lid hygiene measures for blepharitis, artificial tears for dryness, and oral tetracyclines for more significant inflammation, since they also have anti-inflammatory effects independent of any antimicrobial action.⁷

Complications

• Rhinophyma and other phymatous change - progressive, potentially disfiguring soft tissue overgrowth if untreated
• Ocular complications - chronic blepharitis, recurrent chalazia, and, less commonly, keratitis that can threaten vision if not treated promptly
• Psychological impact - embarrassment, reduced self-esteem and social avoidance related to visible facial flushing and erythema, often disproportionate to the objective severity
• Persistent oedema (Morbihan syndrome) - a rare complication with chronic, non-pitting facial swelling that responds poorly to standard treatment

Red flags

Prognosis

Rosacea is a chronic condition with a relapsing and remitting course; it is not cured by any current treatment, but the great majority of patients achieve good control of erythema and inflammatory lesions with consistent sun protection, trigger avoidance and appropriate topical or oral therapy.³

Established phymatous change and background telangiectasia respond poorly to medical treatment once fixed, which is why early recognition and consistent treatment of the inflammatory phase - rather than waiting for structural change to develop - gives the best long-term cosmetic and functional outcome.