- Post inflammatory hyperpigmentation (PIH) is usually caused by acne.
- Post inflammatory hyperpigmentation is more common in individuals with darker skin.
- Topical treatments for PIH include creams and chemical peels.
- Laser therapy and natural treatments are sometimes used to treat PIH, but more research is needed to provide their efficacy.
Post inflammatory hyperpigmentation occurs when a dark patch of skin appears after a blemish or injury heals.
While this pigmentation sometimes fades on its own, this can take a while, so many people turn to over the counter creams or professional dermatology treatments to lighten their pigmentation more quickly.
Preventative measures, such as wearing sunscreen and not picking at acne, can also help reduce or prevent the appearance of post inflammatory hyperpigmentation.
What is post inflammatory hyperpigmentation?
Hyperpigmentation occurs when patches of skin appear darker than the surrounding skin. These darker patches are caused by the overproduction of melanin, which happens when melanocytes are triggered to release excessive pigment granules, which are called melanosomes.
Post inflammatory hyperpigmentation is a sub-type of hyperpigmentation that occurs when melanin overproduction is triggered by inflammation. Post inflammatory hyperpigmentation is especially common in individuals with skin of color, and is one of the most common reasons they seek out a dermatologist.
Post inflammatory hyperpigmentation is separate from melasma, another common sub-type of hyperpigmentation.
Causes of Post Inflammatory Hyperpigmentation
Acne is the most common source of this inflammation, but cuts, burns, and other injuries to the skin can also result in post inflammatory hyperpigmentation in all skin types. The skin produces melanin as part of the healing process, and the more severe the blemish or injury, the greater the risk of dark spots.
Acne causes inflammation to the skin through the life of the lesion, most prominently towards the end of the process, when papules and pustules form on the skin surrounded by redness. When these lesions rupture, they can introduce bacteria into the opening, which further exacerbates the inflammation.
Injuries to the Skin
Whenever you have a cut or burn, your body sends white blood cells to the site to fight off possible infections and guard against bacteria. This concentration of white blood cells produces the symptoms of inflammation, including redness, swelling, and pain.
Diagnosing Post Inflammatory Hyperpigmentation
The classic sign of post inflammatory hyperpigmentation is a spot of darker skin that appears where a blemish or injury has healed. These hyperpigmented patches are most common on the face, neck, and other sensitive areas that are prone to acne and other skin conditions.
The hyperpigmentation will lay flush with the skin. This distinguishes hyperpigmentation from scars, which cause either a loss of tissue or a buildup of tissue, and as a result do not lay flat. You won’t be able to feel the hyperpigmentation, but you will be able to see the dark spots.
Is post inflammatory hyperpigmentation permanent?
Post inflammatory hyperpigmentation may be either temporary or permanent. In some cases, hyperpigmentation will fade on its own, though it may take months or years depending on the severity of the patch. However, some patches of hyperpigmentation are permanent if left untreated.
In general, the higher the contrast between the path and your normal skin color, the smaller the chances that it will fade and the longer it will take if it does.
Post inflammatory Hyperpigmentation Treatments
Understandably, many people don’t want to wait months or years to see if their discoloration will fade or not. There are many treatment options for post inflammatory hyperpigmentation, including topical creams, chemical peels, and laser treatments.
Creams applied to the pigmented patches are one of the most affordable and least invasive ways to treat hyperpigmentation; this will likely be the first routes recommended by the dermatologist. However, topical creams may take longer to affect the desired lightening results.
Often called the “gold standard” in hyperpigmentation treatment, hydroquinone is one of the most common topical treatments. Hydroquinone inhibits the activity of tyrosinase, the enzyme needed to make melanin, which decreases the production of melanin and increases the breakdown of melanosomes. Mequinol, a derivative of hydroquinone, may also be used.
Retinoids such as tretinoin are derivatives of vitamin A and have been shown to treat hyperpigmentation topically. Retinoids accomplish this in several ways, including reducing inflammation and reducing the production of melanocytes.
If topical creams aren’t having the desired effects, your dermatologist might recommend a chemical peel. Chemical peels dissolve the bonds between the top layer of cells using ingredients such as glycolic acid and salicylic acid. This causes the first layer of the dermis to peel away, revealing new skin underneath and stimulating the product of healthy collagen.
Chemical peels are formulated with a variety of ingredients and concentrations to tailor the intensity to each patient. Chemical peels usually only require one session with minimal downtime afterwards.
However, chemical peels do increase your skin’s sensitivity for a short period directly after the peel, which makes your skin more prone to sunburn and inflammation. If the wrong ingredients are used, or ingredients with too high a concentration, chemical peels can actually cause hyperpigmentation.
While topical treatments are by far the most popular choice for post inflammatory hyperpigmentation, some dermatologists turn to laser treatments for especially persistent patches. Lasers reduce and remove hyperpigmentation by breaking up the pigment deposit.
However, not much research has been conducted on the efficacy of laser treatment on post inflammatory hyperpigmentation specifically. More studies are needed into its efficacy and potential side effects.
Some natural ingredients do contain compounds that can address hyperpigmentation. For example, licorice root extract inhibits tyrosinase and can calm inflammation, while vitamin C lightens the skin by interacting with copper ions.
However, only a few limited studies have tested the efficacy of these ingredients in cosmetic formulations, and some of them looked at hyperpigmentation in general, not post inflammatory hyperpigmentation specifically. More studies are needed to confirm whether or not these natural treatments are as effective at reversing pigmentation as the others listed here.
Are treatments covered by insurance?
Treating hyperpigmentation isn’t considered medically necessary, so in many cases it isn’t covered by insurance. However, there is an insurance code that covers post inflammatory hyperpigmentation, ICD-10-CM Diagnosis Code L81.0. If your dermatologist uses this code, you may be able to get reimbursed for the treatment.
Some post inflammatory treatments, such as hydroquinone creams, are available over the counter and don’t need to be covered by insurance regardless
Preventing Post Inflammatory Hyperpigmentation
Prevention strategies for post inflammatory hyperpigmentation aren’t completely guaranteed, but they can significantly reduce your chances of developing the condition. They can also reduce the darkness and size of the patches.
Sun exposure to UV rays stimulates the production of melanin, which can lead to hyperpigmentation or worsen existing patches. Whenever you’re going outside, wear sunscreen with at least SPF 30 for sun protection. Choose a daily moisturizer that provides baseline SPF protection as well.
Don’t pick at acne.
Picking at acne worsens the inflammation and can introduce foreign bacteria that can increase the swelling and even lead to infection. Don’t touch your blemishes unless you’re applying cream, and even then thoroughly wash your hands before and after applying.
Protect your skin.
If you have a cut, burn, or other injury, keep the area clean and apply antibiotics as necessary. Cover the area with a bandage until a scab forms, and don’t pick at the scab once it does form. Wash your hands before and after taking care of your wound to prevent bacteria contamination.
Post inflammatory hyperpigmentation is a relatively common skin condition, especially in people with darker skin who suffer from acne. While some pigmentation may fade with time, over-the-counter creams and chemical peels can help lighten their appearance more quickly. If you’re at risk for post inflammatory hyperpigmentation, you should wear sunscreen and avoid picking at your face to reduce your chances of developing this pigmentation.
- Davis, E. C., & Callender, V. D. (2010). Postinflammatory hyperpigmentation: a review of the epidemiology, clinical features, and treatment options in skin of color. The Journal of clinical and aesthetic dermatology, 3(7), 20–31. ncbi.nlm.nih.gov/pmc/articles/PMC2921758/
- Tanghetti E. A. (2013). The role of inflammation in the pathology of acne. The Journal of clinical and aesthetic dermatology, 6(9), 27–35. ncbi.nlm.nih.gov/pmc/articles/PMC3780801/
- Desai S. R. (2014). Hyperpigmentation therapy: a review. The Journal of clinical and aesthetic dermatology, 7(8), 13–17. ncbi.nlm.nih.gov/pmc/articles/PMC4142815/