Introduction

Though various treatments have been rising and introduced to aesthetic practice to treat multiple skin concerns and issues, chemical peels have been a staple to most clinics for the reason of their multiple uses: relatively cheap (compared to other aesthetic interventions) and for their versatility in strength and depth. As with any other aesthetic treatments out there, a chemical peel can and might give immediate and or long-term complications. Some practitioners, and certainly many patients, do not understand the risks associated with a chemical peel. It is essential for any aesthetic practitioner to know the complications that can arise from and during this treatment, and how the complications must be dealt with.

Complications in Chemical Peels

Immediate complications can include ocular injury, allergic reaction, pruritus and irritation, and a burning sensation. Delayed onset complications, happening within few days to weeks after the chemical peel, include adverse reaction to chemical agent (such as acneic eruptions, hypersensitivity, reaction, toxicity), pigmentary changes (like hypo and hyperpigmentation, demarcation lines, uneven results), abnormal wound healing (as seen in delayed healing, textural changes, scarring), and the effects of a loss in skin barrier or tissue injury (as seen in wound infection). Many complications are sequelae that should not occur after treatment and some may be avoidable with patient selection, appropriate anatomical knowledge, proper pre-treatment care and instructions, material and strength selection, and post-treatment care.

Detailed below are some examples of complications that can arise from all chemical peels; however these complications may be more common and problematic in darker skin patients and with medium and deep peels (as compared to superficial peels):

Ocular Injury: Accidental spillage of chemical on the eye is caused by passing the peel bottle or cup across the periorbital area of the patient while applying the peel, or it is due to oversoaked brush or cotton. This can cause damage to the cornea. To prevent spillage of peels over the eyes, the provider should be very careful while peeling over the periorbital area. A dry swab stick must be kept ready to absorb any tears as peel can trickle up or down if there is watering of the eyes. Petroleum jelly can also be applied in the inner canthus of the eyes before treatment, and one should always avoid passing the chemical agent directly over the patient's eyes.

A syringe filled with saline should be kept ready, and in case of accidental spillage, the eyes should be flushed copiously with normal saline to prevent corneal damage to avoid accidental damage. If phenol peels have been used, the flushing should be done with mineral oil instead of saline. Referral to an ophthalmologist should also be done to ensure that there is no further damage.

Pruritus, Burning, and Irritation: Higher concentrations of chemical peel will possibly influence your patient’s dry and sensitive skin and will result in pruritis, burning, and irritation after a chemical peel. To prevent this from happening the following should be done: select the right peeling agent at the right concentration, prepare ahead a neutralizing agent ready to terminate the peel if required, and apply calamine lotion as a moisturizing base right after the peel. Patients should also be advised to refrain from products with glycolic acid and retinoids until desquamation of the treated area is complete.

Persistent Edema and Erythema:  Proper and strict screening of patients who would want to undergo a chemical peel should be done before any treatment; especially those with a history of photosensitivity, who are using photosensitizing drugs, or have prolonged exposure to the sun. This prevents edema and erythema of the treated area. In addition, patients should be advised to use a broad-spectrum sunscreen with a high sun protection factor (SPF).

Allergic Reactions:  Hypersensitivity reactions could occur during chemical peels among atopic individuals. Testing the peel in the post-auricular region is a must for all patients within the days before the treatment.

Hypo- and Hyperpigmentation:  Pigmentary changes because of complications are usually seen in patients of skin of color. Most of those who have this complication acquired it from the usage of a deep chemical agent, inadequate priming, or lack and improper of sunscreen. Since one should avoid deep peel in patients with darker skin types, different low strength peeling agents can be combined to increase efficacy without increasing the risk.

Adequate priming of the skin is of vital importance. This is done prior to treatment for at least 2-4 weeks in preparation for medium to deep peels (potentially longer for patients with darker skin types), and is discontinued 3-5 days before the procedure. Priming is done by application of depigmenting agents such as hydroquinone or retinoids and the use of sunscreens, as these agents stop the skin from creating excess pigments.

Even with great skin priming, darker skin types should not be given aggressive medium or deep peels due to the risk of having post-inflammatory hyperpigmentation. This is why a thorough understanding of the science behind choosing the correct peel for the correct skin type is essential.

Demarcation Lines: Lines of demarcation can be seen in patients of darker skin types where there is a distinct line between the peeled and untreated area (I.e., face and neck). These can happen when using medium to deep peels. To prevent demarcation lines, feathering the edges using a peeling agent of lower concentration is used to merge with the surrounding normal skin.

Uneven Results: Sometimes the skin may look uneven in color or texture after a peel. The color changes could be pigment-related or induced by localized erythema. This could be because of insufficient skin priming or an uneven application of the peel itself.

To avoid this issue, make sure that your patient will undergo a complete skin priming process, 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.

Scarring, Delayed Wound Healing, and Textural Changes:  Physical malformation and disfiguration of the skin after a chemical peel could take place due to the presence of infection, inadequate photoprotection, patient history of using products that increase skin permeability (such as hydrogen peroxide or tretinoin), innate history of keloid, and poor wound healing because of an underlying disease. The aesthetic provider can also be the reason for this complication if treatment was performed incorrectly; for instance, a chemical agent was not totally or uniformly neutralized and had a much deeper local action than expected.

To prevent these problems, the patient should be started with topical antibiotics and potent topical steroids as soon as the early signs of scarring are noted (such as persistent redness, delayed wound healing, and infection).

Infection:  Infection of the wound can be of different forms like bacterial, candidal, or herpetic—to name a few. The causes of infection of the skin after a chemical peel range from reactivation of viral infection (as noted in herpes simplex) to secondary infections caused by frequent picking, scratching, or scrubbing of the treated area. It is unlikely to get a viral reactivation with superficial peels, but it is not impossible. If the herpetic infection does occur and is neglected, there is a real danger of the herpes virus spreading across large areas of the face and potentially causing pigmentation and scarring.

Bacterial infections, on the other hand, are not very common with chemical peel treatment other than due to hygiene reasons. This is well noted with deep peels because they essentially cause an open wound on the entire treatment area making it susceptible to bacterial entry.

Pre-treatment care for patients with an active lesion or with a history of herpes simplex includes prophylactic antiviral medications. Acyclovir 200 mg for 5 times a day or valaciclovir 1 g for 3 times a day should be given, beginning 2 days prior to the peel and continued for 7 days in the case of medium peels or 10-14 days for deep peels until re-epithelization occurs. Moreover, treatment for a secondary bacterial infection includes the use of antibiotics as soon as the warning signs of infection appear (like crusts, oozing, pustules, or blisters). Patients are strictly warned against picking, peeling, scratching, rubbing, or scrubbing the skin.

Insufficient Results: Unsatisfactory results are caused by the wrong type of peel, the wrong strength, or the wrong intended treatment. Take for example a superficial glycolic peel that is chosen to remove medium to deep wrinkles. Even though multiple superficial peels may be able to be performed on this skin type, the wrinkles will most likely not disappear. To avoid problems with patient satisfaction, one should manage the patient’s expectations from the beginning and choose the correct type of peel, and its correct preparation, for the intended result. Therefore, it’s important that practitioners ensure they have undertaken correct education, so they are able to select the right peel for the needed results of the patient.

Conclusion

Chemical peels are here to stay because of their various types, strengths, and ability to target multiple indications. However, a lack of education, skills, or improper use of this wonderful aesthetic tool can cause many complications. Although adverse effects are more common with medium and deep peels, superficial chemical peels can also be the cause of the problems, so aesthetic providers should be mindful and always consider the potential for complications. All chemical peel treatments should be accompanied by proper patient selection, proper usage of the chemical agent, thorough consultation and assessment, skin priming, pre- and post-treatment care, and a meticulous treatment process to ensure the best results.