Rosacea phenotypes and treatment

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

Rosacea is a chronic relapsing facial inflammatory and neurovascular disorder. Record each feature present rather than assigning one exclusive subtype. Ask about flushing and triggers, then examine central face, scalp margins and eyes for fixed colour change, telangiectasia, papules, pustules, oedema and tissue thickening. Compare with earlier photographs when baseline skin tone makes vascular colour difficult to distinguish.

Treatment follows the dominant problem. Gentle barrier care and photoprotection support every phenotype. Papules and pustules respond to anti-inflammatory topicals or oral doxycycline; persistent vessels may require camouflage or vascular procedures; ocular symptoms need lid and tear-film care with an appropriately low threshold for ophthalmology; phymatous tissue needs specialist intervention. No medicine cures every component.

Shared decisions should distinguish treatment of inflammation from management of background redness. Avoid implying that alcohol causes rosacea: it is one possible trigger among many and may not affect an individual. Ask what products have been tried, whether topical steroids are present, how the condition affects confidence and whether a medicine can be applied safely near—but never into—the eyes.

Key points

Diagnose by features rather than rigid subtypes: persistent centrofacial erythema, flushing, telangiectasia, papules or pustules, ocular disease and phymatous change overlap.
Comedones are not a rosacea feature; their presence suggests acne coexistence or an alternative diagnosis.
In darker skin, persistent erythema may appear dusky, violaceous or brown and is often detected more reliably through warmth, burning, swelling, photographs and dermoscopy.
Ask every patient about gritty, dry, burning or red eyes, lid crusting, recurrent styes, pain, photophobia and altered vision.
Use gentle non-perfumed skin care and daily broad-spectrum SPF 30 or higher; identify personal triggers through a diary instead of prescribing universal avoidance.
Papulopustular disease can be treated with topical ivermectin, azelaic acid or metronidazole; systemic modified-release doxycycline is an option when inflammatory burden warrants it.
Persistent erythema responds differently from papules: camouflage, a carefully tested vasoconstrictor, vascular laser or light treatment may be considered according to expertise and skin type.
Established rhinophyma and other phymatous change need dermatology or procedural assessment; escalating antibacterial therapy will not remove fibrotic bulk.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Innate immune dysregulation

Exaggerated cutaneous innate responses and altered antimicrobial peptides amplify inflammation around central facial vessels and pilosebaceous units.

Neurovascular reactivity

Heat, ultraviolet radiation, temperature change, emotion, alcohol, exercise or spicy food can provoke flushing through individual neurovascular thresholds rather than a universal trigger list.

Barrier and microbial interaction

Impaired barrier function and altered responses to Demodex mites and their associated organisms may contribute to inflammatory papules in susceptible skin.

Medicine aggravation

Potent facial topical corticosteroids can cause or worsen a rosacea-like eruption, while vasodilators may intensify flushing; necessary treatment should be reviewed rather than stopped indiscriminately.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Persistent vascular change
Repeated vasodilatation and vascular remodelling produce fixed centrofacial erythema and telangiectasia, although redness is less visually conspicuous in deeply pigmented skin.
2
Follicular inflammation
Innate immune activation around follicles creates papules and pustules without the open and closed comedones that define acne vulgaris.
3
Ocular surface inflammation
Meibomian-gland dysfunction, blepharitis and conjunctival inflammation cause gritty, burning or dry eyes and can progress to corneal disease.
4
Phymatous remodelling
Chronic sebaceous and connective-tissue overgrowth thickens irregular skin, most often the nose as rhinophyma, and generally requires procedural specialist care.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Persistent centrofacial erythema

Fixed colour, warmth, stinging or burning over cheeks, nose, chin or forehead persists between flushes and may be more palpable than red in darker skin.

Papules without comedones

Inflammatory facial papules and pustules on a sensitive background, without blackheads or whiteheads, support papulopustular rosacea.

Ocular involvement

Lid-margin telangiectasia, blepharitis, recurrent chalazia, grittiness, dryness and conjunctival injection may precede or exceed the skin disease.

Sight-threatening ocular diseaseRed flag

Eye pain, photophobia, reduced acuity or corneal opacity suggests keratitis or ulceration and requires urgent same-day ophthalmic assessment.

Phymatous change

Irregular thickened skin with enlarged follicles, commonly on the nose, reflects tissue overgrowth rather than an acute bacterial abscess.

Atypical departure

Scarring, prominent scale, photosensitive plaques beyond the central face, systemic symptoms or unilateral fixed swelling should reopen the differential.

Red flags requiring action

Eye pain, photophobia, reduced vision, marked corneal redness, rapidly progressive facial swelling, systemic illness or an atypical scarring or photosensitive eruption needs urgent ophthalmic or diagnostic assessment rather than routine rosacea treatment.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Feature-led skin and eye examinationFirst step
Why
Document dominant phenotype, severity and urgent ocular findings.
Interpretation and limitations
Rosacea is usually a clinical diagnosis; absence of obvious redness in dark skin does not exclude inflammation when warmth, burning or papules are present.
02
Trigger and treatment diary
Why
Identify reproducible individual triggers and distinguish treatment irritation from spontaneous fluctuation.
Interpretation and limitations
Repeated temporal association is more useful than a generic prohibited-food list; avoid burdensome restrictions without demonstrable benefit.
03
Visual acuity and focused ocular assessment
Why
Triage ocular surface symptoms and identify potential corneal involvement.
Interpretation and limitations
Normal gross inspection does not neutralise pain, photophobia or reduced vision; urgent ophthalmology is determined by symptoms and corneal findings.
04
Skin scraping, culture or biopsy for atypical disease
Why
Investigate fungal, bacterial, granulomatous, lupus or malignant mimics when morphology departs from rosacea.
Interpretation and limitations
These tests are not routine; choose a representative untreated lesion and give the laboratory a specific differential and relevant treatment history.
05
Targeted autoimmune testing
Why
Assess a credible photosensitive connective-tissue disease phenotype.
Interpretation and limitations
Order according to clinical features rather than using ANA as a rosacea screen, because incidental positivity can create diagnostic noise.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Acne vulgaris

Comedones, truncal acne and adolescent onset favour acne; both disorders can coexist, so examine rather than forcing every facial papule into one diagnosis.

Seborrhoeic dermatitis

Greasy scale in eyebrows, glabella, scalp and nasolabial folds supports seborrhoeic dermatitis, which may coexist with rosacea.

Cutaneous lupus erythematosus

Photosensitive fixed plaques, scale, dyspigmentation, scarring, oral ulcers or systemic features require targeted lupus assessment rather than empirical long-term rosacea therapy.

Periorificial dermatitis

Grouped small papules around mouth, nose or eyes with vermilion sparing and corticosteroid exposure favour periorificial dermatitis over diffuse centrofacial rosacea.

Contact or steroid dermatitis

Prominent itch, scale, a product distribution or rebound after facial corticosteroid use suggests dermatitis or a steroid-induced rosacea-like eruption.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01Papulopustular phenotypeSuppress inflammatory lesionsFirst stepFacial papules or pustules occur without comedones and without sight-threatening ocular features.

1Start gentle cleanser, non-comedogenic moisturiser and SPF 30 or higher, remove inappropriate facial corticosteroid exposure through a planned approach, and agree one topical anti-inflammatory option.
2Use ivermectin once daily, azelaic acid twice daily or metronidazole twice daily according to the chosen product; apply away from eyes and set the product-specific response point.
3For more extensive or resistant inflammation, consider modified-release doxycycline and review after a defined course; reassess diagnosis if there is no meaningful response.

02Vascular-predominant phenotypeAddress flushing and fixed erythemaPersistent colour change, telangiectasia or flushing dominates over inflammatory papules.

1Use a diary to identify personal heat, ultraviolet, drink, food, exercise, medicine or emotional triggers while avoiding unnecessary restrictions.
2Offer camouflage and discuss a licensed topical vasoconstrictor where appropriate, testing a small amount because excessive application can cause marked pallor or rebound redness.
3Refer for vascular laser or intense pulsed light when desired and suitable, using an operator experienced with the patient’s skin tone to reduce burn and dyspigmentation risk.

03Ocular or phymatous diseaseEscalate beyond routine facial careEscalationPersistent lid or eye symptoms, corneal warning features or established tissue thickening is present.

1Assess visual symptoms, acuity and ocular surface; give lid-hygiene and lubricating advice for uncomplicated symptoms while arranging clinical review.
2Seek same-day ophthalmology for pain, photophobia, visual change or corneal abnormality and do not rely on a skin topical to protect sight.
3Refer phymatous change for dermatology and procedural options such as laser, electrosurgery or excision after inflammatory activity is assessed.

Key medicines and prescribing safety4 treatments · regimens, roles and cautions

A licensed treatment for inflammatory papules and pustules of adult rosacea, with anti-inflammatory and anti-Demodex activity.

Ivermectin 10 mg/g cream

Apply one pea-sized amount to each of five facial areas once daily for up to four months, spreading a thin layer and avoiding eyes, lips and mucosa.

For adults only; stop if there is no improvement after three months, avoid oral ingestion and mucosal contact, and consider pregnancy, breastfeeding and local irritation.

A licensed topical option for papulopustular facial rosacea and useful alternative when an antibiotic is undesirable.

Azelaic acid 15% gel

Apply about 0.5 g, a 2.5 cm strip, to the whole face twice daily after cleansing; reduce frequency or interrupt briefly if irritation is troublesome.

Avoid eyes, mouth and other mucosa, wash hands after use, and stop and reassess if rosacea has not improved after two months.

A licensed anti-inflammatory topical for rosacea papules, pustules and erythema when acceptable to the patient.

Metronidazole 0.75% cream

Apply a thin layer to affected facial skin twice daily, morning and evening, after mild cleansing for an average three-to-four-month course.

Avoid eye and mucosal contact, reduce or interrupt for irritation, avoid strong ultraviolet exposure and stop if no clear clinical improvement.

A licensed sub-antimicrobial anti-inflammatory treatment for papulopustular lesions of facial rosacea in adults.

Doxycycline 40 mg modified-release capsules

Take one capsule once daily in the morning on an empty stomach, preferably at least one hour before or two hours after food, with adequate water while upright.

Not for ocular manifestations; avoid pregnancy, breastfeeding and children under 12, consider oesophagitis and photosensitivity, and separate from antacids or mineral products as directed.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Corneal disease

Untreated ocular inflammation can cause keratitis, ulceration, scarring and visual loss, so pain, photophobia and vision change require urgent ophthalmic review.

Rhinophyma

Progressive nasal tissue hypertrophy alters contour and may obstruct airflow; medical control of inflammation does not reliably reverse established overgrowth.

Psychosocial burden

Unpredictable flushing, visible vessels and erroneous assumptions about alcohol can cause stigma, avoidance, anxiety and occupational difficulty.

Treatment-related rebound

Facial corticosteroids and poorly supervised vasoconstrictors can generate rebound erythema, while excessive active products worsen barrier burning and adherence.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

Use feature-specific outcomes: inflammatory lesion count, flushing frequency, fixed erythema, eye symptoms, treatment stinging and patient-prioritised function should not be collapsed into one score.
Review ivermectin by three months and stop if no improvement; respect the four-month licensed course and reassess before repeating.
For azelaic acid, metronidazole or doxycycline, check actual frequency, treated area, irritation, administration and response at the agreed product-specific interval.
Ask again about grittiness, recurrent styes, pain, photophobia and vision at every review because ocular disease can evolve independently of facial papules.
Photographs for vascular change require consent, secure handling and consistent lighting; absence of visible red pixels is not proof that burning inflammation has resolved.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Phenotypes overlap

A person can have papules, persistent erythema and ocular disease simultaneously, so one historic subtype label should not narrow assessment.

Comedones redirect the diagnosis

Blackheads or whiteheads indicate acne, although coexisting rosacea may still explain flushing and central sensitivity.

Redness is not always red

In deeply pigmented skin, warmth, oedema, burning and dermoscopic vessels may disclose vascular inflammation more clearly than unaided colour.

Ocular disease may lead

Blepharitis and recurrent chalazia can precede obvious facial signs, making an eye history essential in an apparently skin-limited consultation.

Fibrosis needs a procedure

Antibiotics may settle inflammation around rhinophyma but do not reliably remove established bulky connective-tissue overgrowth.

11Common pitfallsFrequent interpretation and management errors.

01
Assuming rosacea is absent because central erythema is not bright red on richly pigmented skin.
02
Using one topical to treat flushing, papules, ocular disease and rhinophyma without defining its actual target.
03
Calling every facial pustule acne while failing to examine for comedones, telangiectasia and ocular symptoms.
04
Continuing a potent facial corticosteroid because it briefly suppresses colour while provoking rebound and steroid rosacea.
05
Reassuring eye pain or photophobia on the basis of a mild skin examination and delaying urgent ophthalmic review.