why can hyaluronic acid sometimes cause redness and inflammation?

Hyaluronic acid is an extremely complex and hydrophilic sugar. It is naturally present in the human body in the joints, muscles, eyes and especially in the skin. Almost 50% of its total quantity is found in the dermis, the deep layer of the skin. It constitutes the extracellular matrix and serves as a support for collagen and elastin fibers. It also ensures skin hydration, as hyaluronic acid acts as a molecular sponge: it captures water molecules and retains them.

Nevertheless, over the years, the body's production of hyaluronic acid tends to decrease (a drop of about 6% per decade), which leads to skin slackening. The first wrinkles appear and a decrease in cellular activity is happening. From the age of 50 onwards, it has been proven that the amount of hyaluronic acid in the skin is divided by two. Given this fact, it is particularly interesting to provide the skin with hyaluronic acid via dermocosmetic treatments. Indeed, it is less invasive and therefore much less risky than injections.

For a more noticeable effect on wrinkle reduction, injections are still very effective! But what side effects can they cause?

In surface application, hyaluronic acid is a molecule that is generally well tolerated by all skin types and does not have a potential for sensitization. Normally, it does not present any undesirable side effects in cosmetics or cause hyaluronic acid burns.

It is in aesthetic medicine, in the range of anti-wrinkle injections, that hyaluronic acid can be irritating. Nevertheless, it should be noted that according to the A.N.S.M., adverse effects related to hyaluronic acid injections affect only 0.1 to 1% of people.

The most common side effects following a hyaluronic acid injection are edema, skin redness, itching, erythema and slight bruising. There is no need to worry about them, they are common and vanish in a few days.

Regarding postoperative complications or more serious side effects, it is important to identify them and explain them to patients before any injection, even if they remain exceptional.

• Hyaluronic acid allergy, although rare, exists and can cause a localized inflammatory reaction similar to hives.

• Granulomas may appear on the treated areas. These are small nodules that are sometimes unpleasant and painful. They often remain regressive and fade spontaneously within a few weeks. A specific treatment with cortisone or anti-inflammatory drugs is a solution to relieve the patient.

• Another complication is that people who are prone to cold sores may develop them after the injection; these usually disappear within ten days.

• Abscesses have also been reported, but this complication remains an extremely rare phenomenon.

Contrary indications: Pregnant or breastfeeding women should not perform surgical injections of hyaluronic acid. It is the same for all the people allergic to hyaluronic acid.