This month, we cover a dermatology article about a very common concern: Melasma and post-inflammatory hyperpigmentation. These are the most common types of pigmentation problems, and are especially prevalent in people with darker skin. While people with darker skin have better protection from skin cancer and premature skin aging, they tend to suffer more from pigmentation problems.
Introduction and Background:
It can be psychologically distressing to patients to have patches of skin that contrast with their overall skin tone. As a baseline, people with a darker skin tone have a higher rate of hyperpigmentation or darkening of the skin. For the purposes of this summary, we will focus on two of the most common types of hyperpigmentation: Melasma and Post-inflammatory Hyperpigmentation.
Melasma is a problem of pigmentation. Symptoms include symmetrical macules and patches (similar dark spots on both sides) usually on the face. The forehead, cheeks, and chin are often affected as they are commonly exposed to the sun. In melasma, a combination of estrogen and sun exposure is thought to be the main triggers, and for this reason, women are affected more often. Post-inflammatory hyperpigmentation (PIH) is another common concern, especially among people with a darker skin tone. Inflammation or injury can trigger melanocytes to trigger excessively, creating spots that often resemble the original injury. Skin conditions like acne, eczema or psoriasis, and even blunt trauma can trigger PIH.
Treatment for both pigmentation problems is challenging. In particular, with melasma, it isn’t uncommon for even a small amount of sun exposure to the trigger and brings back the melasma that was treated. Prevention by severely limiting sun exposure remains an important part of treatment for PIH. If hyperpigmentation is the result of chronic skin conditions like acne, treating and managing the acne is critical.
Challenges of Treatment:
There are several frustrating elements for the patient when treating PIH and melasma:
- Frequency of recurrence
- Lack of a reliable preventative option
- Few treatments offering a reliable cure
Prescription: Alitretinoin 30 mg orally, once daily, for 6 months
Spontaneous remission also occurs and is relatively common in PIH. However, it is this unpredictability that makes treating these conditions challenging. There are good preventative advice for both melasma (avoid sun exposure) and PIH (avoid trauma to the skin; treat any skin conditions), they are not universally reliable or practical in many cases.
All treatments start with prevention. Sun protection is a requirement for treatment success. Any therapeutic benefits will likely be negated if strict sun protection is not adhered to when treating hyperpigmentation, and especially with melasma. It is not uncommon for successfully treated melasma to quickly come back after being exposed to the sun so ongoing prevention is important.
- Broad-spectrum sun protection is critical
- Physical blockers (titanium dioxide and zinc oxide) are recommended
- Chemical sunscreens like Avobenzone, Octocrylene, Oxybenzone, ecamsule, are also effective alternatives
Hydroquinone and Combination Products:
Hydroquinone is the best-studied topical depigmenting agent, and usually the first-line treatment in North America.
- Adverse effects include irritation, allergic contact dermatitis, and rarely ochronosis.
- The depigmenting effect is augmented when combined with a retinoid and a corticosteroid.
- Practitioners are advised to limit continuous treatment of hydroquinone to 3-6 months to minimize the side-effects. Shorter courses are still very effective in treating melasma and PIH.
- Retinoids interfere with melanosome transfer, and also directly inhibit tyrosinase. They are not recommended as monotherapy due to irritation. Combining the therapy with low potency corticosteroid helps limit irritation.
A number of alternative products have entered the market. Irritation and unwanted side-effects were considered problematic.
AzA, tranexamic acid, resorcinol, mequinol, and kojic acid are common alternatives.
- AzA has antityrosinase activity, as well as an anti-inflammatory agent
- Tranexamic acid reduces tyrosinase activity
- Kojic acid is an antioxidant that has been used in combination therapy
- Botanically derived antioxidants and natural extracts can sometimes be used to help lighten the skin, or for its anti-inflammatory effects
- Chemical peels are reported as an effective treatment of hyperpigmentation
- Salicylic acid, Jessner’s solution, and Glycolic acid are often used as the agent with little risk of complications
- Combination peeling agents are a recent addition that may also help treat other conditions such as pigmentation, scarring, and wrinkles as well
- It’s the author’s opinion to limit the use of peels, with the exception of salicylic acid
Intense Pulsed Light:
- IPL is not a first-line treatment for melasma or PIH
- The results of the studies are not promising
- Dyschromia or worsening of the condition is a possible side-effect
- This treatment is also not ideal for darker skin types, which is problematic as these populations are the most likely to have problems with PIH and melasma
- This therapy should be seen as a last resort
- Although the initial studies seemed promising, in practice its application appears to be quite limiting
- Rebound pigmentation or worsening of the condition is a risk
- People with darker skin tones are at elevated risk for these side-effects, which is a problem as they are most likely to have PIH or melasma
- Radiofrequency is becoming more popular in cosmetic dermatology as well as for treating melasma
- There is little to no risk of hyperpigmentation as it does not target melanin
- This technology used specifically for treating hyperpigmentation is still new and requires further study
Conclusion and Takeaway:
Currently, the treatment starts with conservative measures that are evidence-backed. If it doesn’t work, or there are special circumstances where the first line is ineffective or a lower line intervention is preferred, then it goes down the list.
First line: Combination topical therapy with sun protection/sunscreen
Second line: Superficial chemical peels, low-fluency/low-density non-ablative lasers
Third line: Fractional radiofrequency, Q-Switched lasers, high fluence lasers, pulsed dye lasers, IPL, micro-needling, spot liquid nitrogen treatment
All of these interventions must work with constant sun protection to minimize the chance of recurrence. From a patient perspective, it’s important to know that there are many interventions available for treating hyperpigmentation, each with its own advantages and disadvantages.