Rosacea: Clinic, diagnosis and treatment

• Rosacea is a skin condition that causes redness and lesions to appear on the face, especially on the cheeks, nose, forehead and chin.
• Symptoms may include dilated blood vessels, papules (red pimples) that may develop into pustules.
• Rosacea can also cause thickening of the skin (especially of the nose, a phenomenon called rhinophyma), redness and irritation of the eyes (blepharitis, keratitis and conjunctivitis).
• The disease is more common in fair-skinned people and can be aggravated by factors such as stress, heat, sun exposure and alcohol consumption.
• There is no definitive treatment for rosacea, but there are treatments to relieve symptoms^2,3,5.
• In France, rosacea is a common skin condition, affecting approximately 3 million people, according to the French National Academy of Medicine. It is more common in women but can also affect men.
• The disease is usually diagnosed between the ages of 30 and 50, but it can also occur in young adults and the elderly.
• It is important to note that although rosacea is not serious, it can have a significant impact on the quality of life of those affected, due to the redness and itching it can cause, as well as negative self-awareness^2,3,5.

The precise etiology of rosacea remains unknown; however, several factors are thought to be involved in its development:

• Genetic factors play an important role in the etiology of the disease, as it is more common in people with a family history of rosacea.
• Hormonal factors are also considered to be involved in its development, as it is more common in women and can worsen during menopause.
• Environmental factors such as exposure to the sun, the wind and extreme temperatures can also contribute to the development of rosacea^3,6.

The physiopathology of rosacea is complex and multifactorial.

• It is generally accepted that the disease is related to vascular hyperreactivity, which leads to redness and dilated blood vessels in the affected areas.
• In patients with rosacea, Demodex folliculorum, a saprophytic parasite, is involved in the inflammatory phenomena.
• Lesions are thought to be promoted by immunization against Demodex proteins or the bacteria it contains (Bacillus oleronius).
• The frequency of Demodex carriage is higher in affected patients than in unaffected patients and its density is higher in affected skin areas than in healthy skin areas in the same subject^2,3,6,8.

The diagnosis of rosacea is mainly based on the clinical examination of the skin. It is usually carried out by a dermatologist or a general practitioner. Diagnosis criteria include the appearance of redness and pimples on the face, as well as dilated blood vessels (telangiectasias) and changes in the nose (rhinophyma) in severe cases.

There are different subtypes of rosacea, each with specific symptoms^1,2:

Erythematous rosacea

• It is characterized by redness on the face, often accompanied by pimples and dilated blood vessels.
• Most of the time, it affects the cheeks but can spread to the whole face.
• The duration is more than 10 minutes. It is accompanied by superficial burning sensations^1,2.

Papulopustular rosacea

• It is characterized by redness and spots on the face, similar to acne.
• These are red papules of 2 to 5 mm in diameter, surmounted by white spots (papulopustules) located on the central facial regions (nose, cheekbones), then affecting the chin and forehead in more severe forms.
• The lesions evolve in successive flare-ups, becoming more and more extensive and unsightly, interfering with social relations (people tend to associate rosacea with alcoholism)^1,2.

Phymatous rosacea

• It is characterized by a thickening of the skin and dilated blood vessels on the nose.
• It mostly affects men over the age of 50. The nose is affected (rhinophymas) with a budding aspect of the nasal pyramid that can be monstrous-like^1,2.

Ocular rosacea

• The average age of onset for this form of rosacea is 50 years old.
• It affects a predominantly female population.
• There is no simultaneous evolution, as ocular rosacea may precede cutaneous rosacea by several months.
• Functional signs are related to dry eyes and triggered by irritation: lacrimation, conjunctival burning.
• Ophthalmological examination reveals conjunctivitis or keratitis, often associated with palpebral inflammation (blepharitis)^1,2.

Pediatric rosacea

• It is rarer in children and teenagers.
• The evolution and the subtypes are the same as in adults.
• It mostly affects children from families with a history of rosacea⁷.