What is Postinflammatory Hyperpigmentation?
Postinflammatory hyperpigmentation, or PIH, is a skin condition that often happens after some sort of skin inflammation or injury. It is a long-lasting condition and is seen more often, and is usually more severe, in individuals with darker skin tones (known in medical terms as Fitzpatrick skin types III-VI). Even though this condition tends to get better on its own, it can take a long time, possibly even years, for it to improve completely. So, people with this condition often need to be treated for a long period of time. Using a combination of different treatments tends to be the most effective way to manage this condition.
What Causes Postinflammatory Hyperpigmentation?
Skin inflammation can lead to a condition called hyperpigmentation, which is when patches of skin become darker than the surrounding skin. This condition is more common in people with darker skin and can be caused by various issues like severe acne, atopic dermatitis (an allergic skin condition), and impetigo (a skin infection usually caused by bacteria).
Other causes of hyperpigmentation encompass a range of categories:
1. Infections: These could be a result of viruses (viral exanthems), fungi (fungal infections), or bacteria (Impetigo).
2. Allergic/Immunologic: These could result from contact dermatitis (a skin rash caused by contact with a certain substance), Atopic dermatitis (a chronic condition that causes inflamed skin), or different immune diseases like Scleroderma, Sarcoidosis, Systemic lupus erythematosus (an autoimmune disease), or Dermatomyositis, or even a reaction to an insect bite.
3. Papulosquamous Disorders: This type involves inflammations due to conditions like Psoriasis, Lichen planus (an inflammatory skin condition), Pityriasis rosea (a rash), or Lichen simplex chronicus (long-term skin condition).
4. Cutaneous Injury: This involves hyperpigmentation due to physical assaults on the skin such as laser or light therapy, burns, cryotherapy (a pain treatment that uses a method of freezing), chemical peels, or radiation therapy.
5. Medication Hypersensitivity Reactions: This can happen due to an allergic reaction to certain medications.
6. Miscellaneous: This includes causes like Acne vulgaris (common acne), Mycosis fungoides (a type of lymphoma), or Erythema dyschromicum perstans (a rare skin disorder).
Risk Factors and Frequency for Postinflammatory Hyperpigmentation
Post-Inflammatory Hyperpigmentation, or PIH, can happen to anyone regardless of skin type. It occurs most frequently in individuals with darker skin types (known as Fitzpatrick skin types III-VI). The darker the skin is, the stronger and more lasting the hyperpigmentation tends to be. There’s no difference between males and females when it comes to PIH. Up to 65% of people with darker skin who have acne may experience PIH.
Signs and Symptoms of Postinflammatory Hyperpigmentation
PIH, or post-inflammatory hyperpigmentation, is a condition that often occurs after a person has had an inflammatory skin disorder or skin injury. It leaves irregular, darker patches or spots on the skin where the original inflammation or injury was. After the inflammation has gone away, PIH doesn’t cause physical symptoms. However, it can still cause emotional distress and affect a person’s quality of life.
When a doctor examines the skin, they might see darker spots that are tan, brown, or dark brown. These spots can stay on the skin for months or even years without treatment but generally begin to fade as the original skin issue gets better. Sometimes a special light (called a Wood’s lamp) can make these spots glow. Some darker spots can be blue-gray and could be permanent. Sometimes both types of darker spots can be present. If there is still inflammation, red bumps, plaques, or nodules may also be seen.
Testing for Postinflammatory Hyperpigmentation
Diagnosing PIH, or Post-Inflammatory Hyperpigmentation, usually involves a simple examination by a doctor. A special ultraviolet light called a Wood’s Lamp can be used to see whether your skin’s upper or lower layer is affected. Sometimes, if the doctor isn’t sure what is causing the issue or wants to confirm PIH, they might take a small sample of your skin, a process known as a biopsy. If you have certain signs and symptoms, your doctor may also recommend laboratory tests to rule out conditions such as Addison’s disease, a disorder that occurs when your body doesn’t produce enough hormones, and systemic lupus erythematosus, an autoimmune disease.
Treatment Options for Postinflammatory Hyperpigmentation
Treating PIH, or post-inflammatory hyperpigmentation (a condition where your skin produces too much pigment, resulting in dark spots), usually involves different steps and methods. One of the key parts of treatment is shielding your skin from the sun every day.
The first step in treatment is to manage any existing inflammation, which might be causing the hyperpigmentation. After doing this, we usually move to a lightening cream, and then, if needed, to chemical peels and laser therapy.
Lightening creams work to reduce the amount of melanin, or skin pigment, being produced. The most common option is a cream called hydroquinone. If hydroquinone is too irritating, you might be given a less irritating option called mequinol. These creams are often used together with another cream, called a retinoid, that helps to make the treatment work faster and better. Sometimes, a low-strength steroid cream might be added to lessen irritation, but usually only for a short time to avoid causing unwanted skin changes. Retinoids can be used in the long term as they help with not only PIH but also acne. Azelaic acid is another option which can be used for treating both acne and PIH.
If the PIH is severe or not responding to creams, we might look at chemical peels. These work by taking off the top layer of your skin, which might hold excess melanin. There are different types of chemical peels, with common ones including glycolic acid, salicylic acid, and trichloroacetic acid. These need to be done carefully by experienced professionals to avoid skin irritation and additional hyperpigmentation.
In some cases, we could use laser therapy to treat PIH. Lasers work by using light to target and break down excess melanin. There are multiple types of lasers, such as Q-switched ruby lasers, Q-switched Nd:YAG lasers, short, intense pulse lasers, and something called fractional photothermolysis. These also need to be used cautiously by experienced professionals to avoid skin irritation and additional hyperpigmentation.
Keep in mind that treating PIH can take a long time, and you may need treatment for months or even years. However, the good news is that with patience and diligence, improvement is generally achievable.
What else can Postinflammatory Hyperpigmentation be?
When doctors diagnose postinflammatory hyperpigmentation, i.e. dark patches on skin after inflammation heals, they carefully consider other conditions that might be responsible for the observed symptoms:
- Melasma (dark patches on the face)
- Solar lentigines (sun spots)
- Tinea versicolor (fungal infection that causes small patches of skin to become lighter or darker)
- Acanthosis nigricans (patches of dark, velvety skin)
- Lichen planus pigmentosus (condition causing discolored patches on the skin)
- Macular amyloidosis (skin condition causing a patchy brown discoloration of the skin)
- Ochronosis (dark patches caused by accumulation of a certain acid in the body)
- Erythema dyschromicum perstans morphea (skin condition where areas of the skin become red, then turn dark)
- Discoid lupus erythematosus (chronic skin condition causing sores with inflammation and scarring).
What to expect with Postinflammatory Hyperpigmentation
Epidermal hyperpigmentation, which is a darkening of the skin, usually lightens or improves within 6 to 12 months. However, dermal hyperpigmentation, or darkening of the deeper layers of skin, gets better slowly, and may never completely fade.
These conditions aren’t known to cause physical health issues. However, they can cause psychological distress, like anxiety or depression. It’s also worth noting that the skin darkening can frequently come back, especially if you’re not using sun protection.
Possible Complications When Diagnosed with Postinflammatory Hyperpigmentation
Untreated PIH, or Post-Inflammatory Hyperpigmentation, can lead to worsening skin darkening and emotional distress. If you’re being treated for PIH, possible side effects may include skin irritation and darkening of the skin after the procedure.
Potential Complications:
- Worsening skin darkening when not treated
- Emotional distress if not treated
- Skin irritation with treatment
- Skin darkening after treatment procedures
Preventing Postinflammatory Hyperpigmentation
At the start of their treatment and consistently throughout, patients should ensure they’re guarded against ultraviolet radiation all year round. They can do this by regularly applying sunscreen and dressing in protective clothing. It’s important to follow these precautions regardless of one’s skin color. People with darker skin tones could be less likely to use sun protection, often because they may not think it’s important. But with proper education about the advantages of sun protection, this can be improved.
