Infection after Aesthetic Treatments: Symptoms, Cold Sore Flare-ups, Late Infection and What to Do

What is infection after an aesthetic treatment, and why does it occur?

Procedures such as injections, lasers, peels or threads create an opening in the skin, however small. If germs present on the skin or in the environment enter the tissue through this opening, an infection can develop. This is uncommon with procedures carried out by a physician, in a healthcare facility and with proper skin cleansing; however, no procedure is free of infection risk.

The source of the infection is most often the skin’s own bacteria. Less commonly, a contaminated product, a non-sterile needle or an unsuitable environment is responsible. This is why where, by whom and with which product the procedure is done directly affects the risk of infection.

Normal healing or infection? How can you tell them apart?

In the first days after the procedure, mild redness, swelling, tenderness and small bruises are common. These are usually most noticeable in the first days and then decrease a little each day. With an infection, on the other hand, the picture gets worse instead of better. The direction of the symptoms, that is, whether they are decreasing or increasing, is the most helpful clue for telling them apart.

This table is a general guide and does not make a diagnosis. If you are not sure, call the physician who performed the treatment and show them a photo of the area.

When is it an emergency? For which symptoms should you not wait?

After filler, discolouration, whitening or severe pain may point more to vascular occlusion than to infection; this is far more urgent and is described in detail on the page “After Fillers: When Is It an Emergency?”.

What is an abscess, and how can it be recognised?

An abscess is a collection of pus within the tissue. It usually appears as a red, warm, painful bump that feels as if it is filled with fluid when touched. An abscess may not go away on its own; it often needs to be assessed by a physician and, if necessary, drained.

Squeezing an abscess at home, piercing it with a needle or pressing on it can spread the infection deeper or to the surrounding area. On the face, especially around the nose and eyes, this is even more important.

Why do cold sores appear after a treatment around the lips?

A cold sore appears when the herpes simplex virus, which lies dormant in the body, is reactivated. Tissue trauma from procedures such as lip filler, or lasers or peels around the lips, can trigger a flare-up in people with a history of cold sores. In the literature this is considered uncommon; however, there are no reliable data on how often it occurs.

A cold sore usually starts in the days after the procedure with a tingling or burning sensation, followed by clusters of small fluid-filled blisters and crusting. It can sometimes be confused with a bacterial infection or with a circulation problem after filler. This is why it is important for your physician to see such blisters when you notice them.

If you have a history of cold sores, be sure to mention it before the procedure. Depending on the type of procedure and your history, your physician may decide whether preventive treatment is needed. As a general principle, no procedure is carried out on an area with an active cold sore.

Infections appearing weeks or months later: atypical mycobacteria

Some infections appear not immediately after the procedure but weeks or months later. An important example is skin infections caused by rapidly growing mycobacteria (atypical mycobacteria), which are relatives of the tuberculosis germ but do not cause tuberculosis. These germs can be found in water and the environment; they can be carried into the tissue by a contaminated product, non-sterile materials or inadequate cleaning conditions.

In a cluster of cases after mesotherapy in France, patients developed painful, red, oozing nodules (lumps that can be felt) at the injection points; treatment was long and recovery took months. The U.S. Centers for Disease Control and Prevention (CDC) has also reported similar outbreaks of infection after cosmetic surgery procedures; in that outbreak, symptoms were reported to have started on average about two months after the procedure, and shortcomings in cleaning and disinfection were found at the clinic.

These infections often do not respond to standard antibiotics; they may require special culture tests and long-term treatment under specialist supervision. So if you have a wound or swelling that appears weeks later, does not go away, oozes or hardens, be sure to tell the physician about the procedure you had in the past (where, when, which product). For details, see the pages “Mesotherapy” and “Counterfeit Products and Unlicensed Treatments”.

Filler and biofilm: why does late inflammation occur?

A biofilm is a community of bacteria that attach to a surface and surround themselves with a protective layer. Some research suggests that low-level bacterial presence and biofilm may play a role in some of the red, painful swellings seen in filler areas weeks or months later. The subject is still being researched, and not every late swelling is an infection; some are the immune system’s reaction to the filler.

Making this distinction and choosing the right treatment requires an examination. Late swellings and nodules related to filler are covered separately on the page “Filler Complications”.

When do signs of infection start?

Bacterial skin infections mostly appear in the first days after the procedure. Cold sore flare-ups are also usually seen in the days following the procedure. In contrast, atypical mycobacterial infections and some late conditions related to filler can start weeks or even months later. This is why it is easy not to connect a complaint that appears long after the procedure with the procedure itself.

Whenever you see a physician, mention the procedures you have had in that area, even if they were done months ago. This information can help the physician request the right tests and avoid unnecessary treatments.

What can your physician do? What are the treatment options?

Your physician will first examine the area and ask when, where and with which product the procedure was done. If necessary, they may take a sample of the discharge or tissue to find out which germ is responsible. If atypical mycobacteria are suspected, these tests may require special methods.

• For a bacterial skin infection, a suitable antibiotic treatment may be planned based on the physician’s assessment.
• An abscess may need to be drained.
• For a cold sore, the physician may recommend an antiviral treatment if necessary.
• For some late conditions related to hyaluronic acid filler, the filler-dissolving enzyme hyaluronidase may be considered based on the physician’s assessment.
• With signs of a widespread infection, monitoring in hospital and intravenous treatment may be needed.

The type and duration of treatment vary greatly depending on the cause of the infection. This is why only the physician who examines you can decide on the right treatment for you.

Why should you not take antibiotics on your own?

• Not all redness is an infection; an allergy, a cold sore, a reaction to filler or a circulation problem can look like an infection, and their treatments are completely different.
• The wrong medicine does not work, especially against special germs such as atypical mycobacteria, and it delays the diagnosis.
• Antibiotics started at random before a culture test can make it harder for the physician to identify the germ.
• Unnecessary use of antibiotics increases the risk of side effects and antibiotic resistance.
• Do not use old medicines left at home, medicines prescribed for someone else or creams recommended online.

What can you do at home, and what should you avoid?

• Keep the area clean; wash your hands before touching it.
• Follow the aftercare instructions your physician gave you; for details, see the page “Aftercare Following Medical Aesthetic Procedures”.
• To track changes, take a dated photo in the same light every day.
• Measure your temperature and write it down.
• Do not squeeze, pierce or pick off crusts.
• Unless your physician recommends it, do not apply warm compresses, massage or herbal mixtures to the area.
• While you have symptoms, do not have a new procedure on the same area and do not use make-up or heavy cosmetic products.

What can be done to reduce the risk of infection?

• Have the procedure done by a physician in a licensed healthcare facility. Settings outside healthcare facilities, such as homes, hairdressers and beauty salons, carry serious risks.
• Make sure a sealed, labelled product of known origin is used; ask for the product and its batch number to be recorded.
• Make sure the skin is cleaned with an antiseptic solution before the treatment and that single-use needles are used.
• Come without make-up on the day of the procedure; if you have active spots, a wound, an eczema flare-up or a cold sore in the area, postpone the procedure.
• Tell your physician about your history of cold sores, any diseases or medicines that affect your immune system, and diabetes.
• Do not touch the area in the first hours after the procedure; avoid make-up, swimming pools, saunas and Turkish baths (hammams) for as long as your physician recommends.

Why are treatments carried out outside healthcare facilities riskier?

With injections carried out outside healthcare facilities, the sterile conditions, the origin of the product and its storage conditions are uncertain. A large proportion of the reported outbreaks of atypical mycobacterial infection have been linked to settings where cleaning and disinfection were inadequate. In addition, if a problem arises, rapid intervention and access to records become more difficult.

If you have had a procedure in such a setting in the past and have no complaints, there is no need to panic; however, keep an eye on the area over the following weeks and see a physician without delay if you notice a new symptom. For the steps you can take if you have a problem, see the page “What Should You Do If a Complication Occurs after an Aesthetic Treatment”.

This page is for general information and does not replace an examination. If in any doubt, contact the physician who performed the treatment or the emergency services.