Preventing Chemical Peel Complications

By Dr Xavier Goodarzian / 13 Sep 2021

Dr Xavier Goodarzian outlines the common complications caused by chemical peels and advises on how to avoid them

Chemical peels have been in use for decades and their formulas and applications have dramatically improved over the years. This has led to products that are much safer and cause fewer side effects. While peels can be a wonderful way of improving skin quality and reducing sun damage, pigmentation, acne, acne scarring and wrinkles, they are powerful tools and like any aesthetic treatment they have the potential to cause complications.

Skin peeling is now a significant part of most aesthetic practices and a common treatment sought by patients, so it is more important than ever for practitioners to be aware of how to avoid and manage these complications, should they arise.

Common side effects

Chemical peels can address various issues and can be adapted for the individual’s skin by altering the combination of ingredients, their percentages, and acidity (PH level). They are also very versatile and can address issues very superficially at the stratum corneum level all the way down to the reticular dermis level, depending on the active peeling agent used (Table 1).1

As a rule of thumb, the more superficial a peel, the less potential side effects one might expect. So, the deeper the peel penetrates, the higher the risk of having side effects. However, this is not to say that superficial peels are totally harmless and cannot cause any side effects at all so they should still be used with the respect they deserve as a medical treatment.

Post-inflammatory hyperpigmentation

Post-inflammatory hyperpigmentation (PIH) occurs when the skin reacts to inflammation by creating extra pigment, causing brown patchy pigmentation in the peeled areas.2 PIH is an issue that can occur with superficial or deep peels, but is particularly common with medium depth peels. This is because TCA can be used on individuals with darker skin types who are more prone to pigmentation, whereas phenol deep peels are not performed on skin of colour. PIH is a problem usually associated with darker skin photo types IV, V and VI because they can create pigment more easily and their skin reacts to inflammation by going darker.3 However, it can occasionally present with lighter skin types.2

The primary cause for this is a lack of proper skin preparation and/or aftercare.3 In my experience, darker skin types must be prepared for longer than the commonly accepted two to three weeks prior to the peel. I would recommend at least six or eight weeks of skin prep in these skin types, and the prep should include the use of skin lightening agents with anti-tyrosinase activity. This is because these agents stop the skin from creating excess pigment.3 This is less important for superficial peels but a must for medium or deep peels.

Also, darker skin types are generally not suitable for aggressive medium or deep peels due to the risk of PIH, and even with great skin prep there is always a risk of causing PIH.2 So, understanding the science behind choosing the correct peel for the correct skin type is essential.

Prolonged downtime and/or erythema

In my experience when undergoing a medium or deep peel, a week of downtime is the minimum that you would expect. With deeper peels the erythema can last for one to two months after the peel, sometimes even longer.2 The downtime can be prolonged by lack of or insufficient skin preparation, so the better the skin is prepared for a peel, the quicker it will recover afterwards and the less chance for potential side effects. Skin prep is really peel dependent, but also very much dependent on skin type, skin condition and skin concern. It’s hard to give a general guideline for this as there are so many variations, but generally I would recommend the use of antioxidants and sun protection at the very least. It is important to explain the length of downtime to your patient during the initial consultation so they can decide whether they are able to commit to this as well as the aftercare, so they can plan their social calendar around it. In my opinion, a chemical peel should never be sold to a patient as a single treatment, but as a package along with the skin prep products so that they can use the correct products for prepping and aftercare. There is no room for negotiation here, and practitioners should be confident to say no to the patient if this is the case and explain the risks fully.

Rebound pigmentation

Pigmentation, especially melasma, can be very difficult and stubborn to treat. Melasma is particularly difficult to eradicate because it has the tendency to come back. This often seems to be the case when the skin preparation phase has been shortened or neglected. Apart from skin prep, aftercare is also vital to keep pigmentation away. Again, the treatment does not simply end with the peel. Skincare products that come afterwards are part of the treatment and so is a good broad-spectrum sunscreen and sun avoidance. I would typically recommend at least two to three months of sun protection after peeling, although of course patients should be using SPF all year round.

Viral or bacterial infections

Chemical peels can reactivate viral infections, with the most common being herpes simplex. A lot of us carry the virus and this can be an issue with medium or deep peels because the virus regularly reactivates with stress, sunlight, low immunity, or irritation.4 It is unlikely to get a reactivation of the virus with superficial peels, but it is not impossible.

For medium and deep peels, it is advisable to start the patient on prophylactic antiviral treatment before the peel. For medium peels a five-to-seven-day course would suffice, whereas with deep peels usually 15 days are required.4 Usually the course of treatment starts one or two days before the peel itself. If this is neglected there is a real danger of the herpes virus spreading across large areas of the face and potentially cause pigmentation and scarring.

Bacterial infections are not very common with peels except in cases where hygiene has been an issue. This can be more of a problem with deep peels because they essentially cause an open wound on the whole area so it would be very easy for bacteria to infect this.4 In my practice, with deep peels a prophylactic course of antibiotics is sometimes prescribed to avoid a potential bacterial infection, typically lasting for a course of seven days.


Scarring is a rare side effect but can happen with peels of any depth. I have known even superficial peels, when performed incorrectly, to cause scarring. A good example of this would be a glycolic peel that has not been totally or uniformly neutralised and has a much deeper local action than expected. So, the problem could be down to the practitioner performing the peel, but it could also be due to the patient using products that would increase skin permeability such as benzoyl peroxide or tretinoin.

This makes it essential for practitioners to perform a thorough consultation in which they gain detailed knowledge of the patient’s skincare regime and medical history. Often patients don’t mention creams they use as they don’t recognise them as medication, but any product put on the face could potentially influence the peel. If scarring does occur, it is important to recognise it early on, so practitioners should always ensure to schedule a follow-up appointment. The first follow-up for medium and deep peels should be as soon as the crusting comes off, which is typically eight to 10 days after the peel. To treat scarring there are several options, including intralesional steroid injections, topical steroid application, topical silicone application, LED light therapy and sometimes even microneedling.2 The treatment will depend on the severity of the scar, and I have found that a combination of treatments usually gets the best outcome.

Insufficient results

Generally, this occurs because the wrong type of peel was chosen for the wrong indication. For example, a superficial peel that was chosen to remove medium to deep wrinkles. No matter how many superficial peels are performed on this skin type, in my experience, those wrinkles will not disappear. To avoid this problem one should manage the patient’s expectations from the beginning and choose the correct type of peel for the indication. Therefore, it’s key that practitioners ensure they have undertaken the correct training/education so they are able to choose the right peel. In this instance, only a deep peel of reticular dermis level would be able to remove medium to deep wrinkles.

Uneven results

Sometimes the skin may look uneven in colour or texture after a peel. The colour changes could be pigment related or induced by localised erythema. This could be because of insufficient skin preparation or an uneven application of the peel itself. To avoid this problem, make sure that your patient has been using their prep products correctly and make sure that the application of the peel is as even as possible. If this complication occurs, the peel may need to be repeated.

Always consider complications

Chemical peels are a wonderful tool to use for skin rejuvenation; however, they can cause various side effects if not used carefully. Although complications are more common with medium and deep peels, superficial peels can also cause adverse events and so particular care should be taken by all practitioners regardless of the depth. All peels should be accompanied by the necessary prep and aftercare products, which practitioners should communicate clearly during the initial consultation and follow-up appointments should be scheduled to ensure this is being implemented correctly. 

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