Dermatology · Papulopustular and Inflammatory Skin Disorders
The facts most likely to be tested
Rosacea is characterized by centrofacial erythema, telangiectasias, and papulopustular lesions that typically spare the perioral and periocular regions.
The primary clinical distinction between rosacea and acne vulgaris is the absence of comedones in rosacea.
Phymatous rosacea presents with skin thickening and irregular surface nodularities, most commonly manifesting as rhinophyma on the nose.
Ocular rosacea is a frequent complication that presents with blepharitis, conjunctivitis, and a sensation of a foreign body in the eye.
Patients should be advised to avoid triggers such as spicy foods, alcohol, sun exposure, and hot beverages to reduce symptom flares.
First-line topical therapy for mild-to-moderate papulopustular rosacea is metronidazole gel or cream, azelaic acid, or ivermectin cream.
Severe or refractory cases of rosacea are treated with systemic therapy, most commonly oral doxycycline.
Vignette unlocked
A 45-year-old woman presents to the clinic complaining of persistent redness on her cheeks and nose that worsens after drinking hot coffee. Physical examination reveals erythema and scattered papules and pustules on the central face, with visible telangiectasias. There are no comedones present on the forehead or chin. The patient reports occasional gritty sensations in her eyes.
What is the most appropriate initial topical treatment for this patient's condition?
Metronidazole gel
The patient presents with classic features of papulopustular rosacea, which is distinguished from acne by the lack of comedones; topical metronidazole is a first-line treatment.
Full handout
High yield triage
Etiology / Epidemiology
Chronic inflammatory condition primarily affecting fair-skinned adults aged 30-50. Often triggered by sunlight, heat, alcohol, and spicy foods.
Clinical Manifestations
Characterized by centrofacial erythema, telangiectasias, and papulopustules. Phymatous changes like rhinophyma are pathognomonic.
Diagnosis
Primarily a clinical diagnosis based on history and physical exam. No specific biopsy or lab test is required for routine cases.
Treatment
First-line topical therapy is metronidazole. Avoid topical steroids as they exacerbate the condition.
Prognosis
Chronic, relapsing course. Ocular rosacea is a significant complication requiring ophthalmology referral to prevent vision loss.
Full handout
Epidemiology & Etiology
Prevalent in individuals of Celtic or Northern European descent. Onset typically occurs between ages 30 and 50. Pathogenesis involves vascular hyper-reactivity and potential immune dysregulation triggered by environmental factors.
Pertinent Anatomy
Affects the convexities of the central face (nose, cheeks, chin, forehead). The involvement of the sebaceous glands is central to the development of phymatous changes.
Pathophysiology
Dysregulation of the innate immune system leads to increased production of cathelicidins. Chronic inflammation causes vasodilation and angiogenesis, manifesting as persistent erythema. Overgrowth of Demodex folliculorum mites may contribute to the inflammatory response.
Clinical Manifestations
Presents with centrofacial erythema, telangiectasias, and inflammatory papules/pustules. Unlike acne, comedones are absent. Rhinophyma (sebaceous gland hypertrophy) is a classic late-stage finding. Ocular involvement (blepharitis, conjunctivitis) is a red flag requiring prompt evaluation.
Diagnosis
Diagnosis is clinical. No gold standard laboratory test exists. Biopsy is reserved for atypical cases to rule out lupus erythematosus or sarcoidosis.
Treatment
First-line topical treatment is metronidazole gel or cream. For papulopustular lesions, azelaic acid or ivermectin are effective. Topical corticosteroids are strictly contraindicated as they cause rebound flares and skin atrophy. Oral doxycycline is used for moderate-to-severe or ocular cases.
Prognosis
Condition is chronic and requires long-term maintenance. Ocular rosacea can lead to corneal ulceration and vision impairment if untreated. Patients should be counseled on strict sun protection and trigger avoidance.
Differential Diagnosis
Acne vulgaris: presence of comedones
Systemic lupus erythematosus: malar rash spares nasolabial folds
Seborrheic dermatitis: greasy yellow scales
Perioral dermatitis: spares the vermilion border
Carcinoid syndrome: associated with flushing and diarrhea