Acne and Rosacea: How to Differentiate Them?

This point is essential but it's not obvious! Indeed, acne and rosacea both come with temporary redness but also permanent redness (erythrosis). In the case of rosacea, these erythroses are also accompanied by small, thin, red or purple blood vessels visible to the naked eye. Moreover, papulopustular rosacea, which is a form of rosacea, can lead to the appearance of inflamed papules and/or pustules, sometimes painful, on the skin surface, exactly like in acne. However, some differences exist between these two skin diseases.

• Areas of occurrence that differ.

  Rosacea primarily affects the face, while acne can be visible on the face but also on other parts of the body such as the shoulders, chest, and back.

• Blackheads that are only present in acne.

  Blackheads are retentional lesions that appear as a result of the accumulation of excess sebum (hyperseborrhea) and a deposit of dead cells known as keratinocytes (hyperkeratinization) that block the hair canals. This mixture, when exposed to air, oxidizes, and thus forms a small, hard, black ball on the surface. On the face, blackheads are especially visible on the T-zone, which corresponds to the nose, chin, and forehead.

  Blackheads are only found in acne, thus allowing for a differential diagnosis between acne and rosacea.

• Signs extra-cutaneous associated solely with rosacea.

  Hot flashes and eye involvement (ocular rosacea) are generally absent in acne. It should be noted, ocular rosacea can sometimes precede skin involvement. It presents as conjunctivitis, eye irritation, eyelid inflammation (blepharitis), watery red eye (conjunctival hyperemia), burning sensation, dryness with a feeling of a foreign body in the eyes, and light sensitivity (photophobia).

• The types of skin and phototypes involved.

  A significant difference between acne and rosacea lies in the fact that acne affects combination to oily skin types , while rosacea can affect all skin types. Moreover, rosacea is more prevalent in individuals with fair skin, while the prevalence of acne is the same across all phototypes.

Rosacea occurs as a result of a disruption in the immune system related to the skin and due to the excessive presence of skin mites (Demodex folliculorum and Demodex brevis) and certain bacteria. It can also result from a malfunction in the operation of blood vessels or even the dysfunction of the Meibomian glands located at the edge of the eyelids in the case of ocular rosacea.

Acne, for its part, is characterized among other things by a hypersecretion of sebum (hyperseborrhea), a deposit of dead cells known as keratinocytes (hyperkeratinization) that clog the hair canals and by the colonization of the skin by a bacterium called Cutibacterium acnes and not by a mite as in the case of rosacea.

Severe acne can unfortunately leave scars on the skin's surface. We refer to these as scars when the mark remains visible 1 year after the lesion has healed. We distinguish two types of acne scars: the atrophic scars that have a sunken appearance and the hypertrophic scars that are slightly raised, presenting a sort ofskin tissue outgrowth. Moreover, acne can also lead to spotsthat are pigmented (brown). This post-inflammatory hyperpigmentation is due to an excessive production of melanin, a pigment present in the skin whose main function is to protect skin cells from UV rays. This type of mark is more common in individuals with medium to dark skin tones.

Rosacea rarely leaves aesthetic scars. Only one type of rosacea, known as Rhinophyma and primarily found in men, leaves distinctive marks characterized by a thickening of the skin on the nose.

Naturally found in certain grains such as barley, azelaic acid is classified among the dicarboxylic acids. It is used in medicinal treatments for acne, applied topically, typically at concentrations between 15 and 20%. In cosmetics, creams and serums rarely contain more than 10%. However, even at this concentration, its overall anti-blemish activity is significant.

In pharmacy, this active ingredient was first formulated in an anti-acne cream in the early 1980s. Subsequently, reports indicated its potential effectiveness in treating rosacea. Thus, a study demonstrated a significant continuous improvement in the number of inflammatory lesions and erythema over a 15-week treatment period using a gel containing 15% azelaic acid.

Today, the mechanisms of action of azelaic acid in rosacea remain largely unknown. However, it is highly likely that the properties anti-inflammatory of azelaic acid, which works by neutralizing reactive oxygen species, also known as free radicals, are responsible for such effectiveness. In addition, azelaic acid has antimicrobial action and can inhibit the production of inflammatory mediators by follicular bacteria, hence the soothing of redness and irritation.

Furthermore, the adverse effects associated with the 15% azelaic acid gel are most often mild or transient and generally do not require the discontinuation of treatment.

Thus, a cream containing azelaic acid is a relevant first-line solution when one wants to effectively combat rosacea.

Find this compound in our matifying serum.

Note : Acne and rosacea are skin diseases, thus a consultation with a dermatologist is essential. Depending on your type of rosacea or the severity of your acne, the dermatologist will prescribe a suitable treatment.

• ELEWSKI B. E. Azelaic acid 15% for the treatment of rosacea. Expert Opinion on Pharmacotherapy(2006).

• LAYTON A. & al. Azelaic acid 15% gel in the treatment of rosacea Harald. Expert Opinion on Pharmacotherapy (2008).