What causes post-inflammatory hyperpigmentation?
Inflammation (such as after acne, eczema, lichen planus, allergic reactions) or trauma to the skin (such as surgery, incorrect use of microdermabrasion, lasers or chemical peels) causes the release of inflammatory cells that cause melanocytes (pigment cells) to produce more pigment in the skin. Severe inflammation or trauma can disrupt the bottom layer of the epidermis (first layer of the skin) causing the pigment to leak into and become trapped in the dermis (second layer of the skin). This results in a deeper and more treatment resistant pigmentation.
Ultraviolet light exposure and certain medications (such as tetracycline antibiotics, antimalarial drugs and chemotherapeutic agents) can make the condition worse.
What does post-inflammatory hyperpigmentation look like?
Post-inflammatory hyperpigmentation is characterised by flat, tan, brown or black spots on the skin. This condition can occur on any area of the body, including in the mouth, the genital areas and on the nails.
What other problems can occur with post-inflammatory hyperpigmentation?
Although this condition affects men and women equally, it is more common in those with skin of colour (pigmented skin).
How is post-inflammatory hyperpigmentation diagnosed?
The condition is usually diagnosed by a physical examination performed by your dermatologist.
In some cases a skin biopsy may be needed to distinguish this condition from other skin conditions that may have a similar appearance. Examples of other conditions that can look like post-inflammatory hyperpigmentation include melasma, hyperpigmented pityriasis versicolor, lichen planus (macular variant), amyloidosis (macular variant) and hyperpigmented mycosis fungoides. A Wood’s lamp (a special light used to examine skin) can be useful in determining the depth of the pigment change.
How is post-inflammatory hyperpigmentation treated?
Most cases resolve spontaneously without any treatment.
Cosmetic camouflage (such as cosmetic foundations and concealers) can be helpful in disguising the difference in skin colour until recovery is complete.
Speed of recovery can be improved with:
- Strict sun protection including the application of a broad-spectrum sunscreen containing zinc and titanium dioxide
- Topical bleaching agents (such as hydroquinone, azelaic acid, tretinoin and corticosteroid creams)
- Chemical peels and laser therapy. Specific lasers with specific settings need to be used by a trained dermatologist to avoid further complications or worsening of the condition.
What is the prognosis/likely outcome of post-inflammatory hyperpigmentation?
Post-inflammatory hyperpigmentation is a benign process but may have significant cosmetic and psychosocial implications.
The condition may take weeks or years to resolve depending on the initial cause, the colour of the person’s skin and if medical treatments are used to hasten recovery.
This information has been written by Dr Michelle Rodrigues