Rosacea Acne: What is it?

"rosacea acne" in common language, papulo-pustular rosacea is a very specific form of rosacea. It is a chronic skin condition that affects the blood vessels, which is confined to the facial area, thereby causing redness, where papules but especially pustules that resemble acne lesions can spontaneously appear on the rosacea background.

Often mistaken foracnewhen it is hormonally induced due to the presence of spots, the difference is that it is not accompanied by comedones (blackheads and whiteheads), seborrhoea, or superficial or deep cysts. Rosacea acne evolves in flare-ups: initially, the eruptions are few, but their number can increase with the flare-ups.

The emergence of rosacea acne is linked to the excessive presence of skin mites, the Demodex, which are naturally present on the skin. The Demodex folliculorum and Demodex brevis are saprophytic mites that live in pilosebaceous units: the Demodex folliculorum is typically found in the follicular infundibulum, while the Demodex brevis in the sebaceous glands.

They are responsible for the redness as well as the presence of papules and pustules observed in individuals suffering from rosacea. The cause of their excessive presence is believed to be due to a immunological disorder which would lead to the formation of a permanent oedema promoting an excessive proliferation of mites Demodex.

Rosacea acne can be treated in various ways. However, it is essential to know the symptoms of its onset in advance and to consult a dermatologist for a diagnosis and to receive the appropriate treatment.

Generally, the treatment of rosacea acne is carried out through the intake of oral antibiotics or a cream. It is recommended not to take oral antibiotics over a long period of time.

• Doxycycline.

  This is an antibiotic from the tetracycline family that is taken orally. Doxycycline has anti-inflammatory activity by reducing the levels of pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α. It is a photosensitising treatment, so it should be avoided during the day or during summer periods. Generally, the usual dosage is 100 mg per day in the evening for 1 to 3 months. Rare side effects such as oesophageal and gastric intolerance are possible in some vulnerable patients.

• The metronidazole at 0.75%.

  This is an antibiotic, antibacterial, antiparasitic from the nitro-5-imidazole family, effective in treating early-stage rosacea acne. Metronidazole is capable of converting into a cytotoxic form via the transfer of an electron from various donors to the nitro group, which converts it into a nitroso free radical. This toxic metabolite primarily interacts with DNA, RNA, or intracellular proteins, causing a loss of the DNA's helical structure and strand breakage, which results in cell death. It is used in twice-daily applications over an average of 2 to 3 months, depending on the severity and duration of the rosacea. It is effective at a concentration of 0.75% and is sometimes used at 1% in preparations.

• The 15% Azelaic Acid.

  This is a second-line treatment in the event of failure with metronidazole. Theazelaic acid is believed to have, in addition to its antimicrobial activity, an anti-inflammatory action by inhibiting the production of inflammatory mediators. However, its mechanisms of action remain poorly understood. This treatment has shown effectiveness when applied morning and evening. Some adverse effects have been reported such as redness, burning and itching.

• The 0.1% Adapalene.

  This treatment is often used in cases of acne due to its anti-inflammatory activity, which inhibits the chemotactic and chemokinetic responses of human polymorphonuclear leukocytes. Improvements in rosacea acne can be observed after 4 to 8 weeks of treatment. However, frequent adverse effects (1 in 10 patients) are reported, such as skin dryness, skin irritation, a burning sensation on the skin, and erythema.

• The 10 mg Ivermectin.

  This treatment would be effective against Demodex type mites, although its mode of action is not well understood. Applied in the evening, the treatment is prescribed for up to 4 months, but a lack of response at 3 months necessitates its discontinuation. Burning sensations, skin irritation, itching, and dry skin are the most common side effects of this treatment.

Managing rosacea acne requires strict adherence to treatment. It also necessitates the adoption of a skincare regimen designed for sensitive skin, while avoiding factors that may trigger flare-ups.

• ROIHU T. & al. Demodex mites in acne rosacea. Journal of Cutaneous Pathology (1998).

• FORTON F. M. N. Papulopustular rosacea, skin immunity and Demodex: pityriasis folliculorum as a missing link. Journal of the European Academy of Dermatology and Venereology (2011).