Symptoms of PIH
Post-inflammatory hyperpigmentation (PIH) manifests as macules or patches in the same distribution as the initial inflammatory process and is characterized by flat, 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. PIH can worsen with ultraviolet (UV) irradiation or with persistent or recurrent inflammation.
PIH is usually a benign affliction but may have significant cosmetic and psychosocial implications. The condition may either be permanent or take weeks or years to resolve depending on the initial cause, the phototype of the person’s skin and if medical treatments are used to speed recovery.
Triggers of PIH
Post-inflammatory hyperpigmentation is a basic biological skin mechanism in response to various triggers:
– Inflammatory skin conditions: eczema, acne, pseudofolliculitis barbae, psoriasis, lichen planus, systemic lupus erythematosus, chronic dermatitis and cutaneous T-cell lymphoma.
– Trauma: injury, surgery, incorrect use of microdermabrasion, lasers or strong chemical peels.
– Photoallergic reactions: perfumes and essential oils
– Phototoxic reactions with certain drugs: bactericidal, antifungal, anti-depressants, hormonal treatments, anti-malarial, anthelmintics, antidiabetic and chemotherapeutic agents.
– Exposure to certain chemicals: silver, gold and arsenic, quinone, benzophenones.
– Occasionally no cause can be identified.
Causes of PIH
A number of inflammatory mediators, including prostanoids, cytokines and chemokines as well as reactive oxygen species, are released during the inflammatory process in the epidermal layer. These stimulate melanocytes to increase the production of melanin. In dermal melanosis, inflammation disrupts the basal layer, causing melanin to be released and trapped in the macrophages of the papillary dermis – known as pigmentary incontinence which gives a characteristic grey-purple-brown colour to the skin.
It is first important to identify potential triggers of the PIH with a dermatologist to eliminate or treat any potential underlying medical causes. In some rare cases a skin biopsy may be needed to distinguish this condition from other skin conditions that may have a similar appearance such as melasma, hyperpigmented pityriasis versicolor, lichen planus (macular variant), amyloidosis (macular variant) and hyperpigmented mycosis fungoides.
A Wood’s lamp (a special UV light used to examine skin) can be useful in determining the depth of the pigment change. Epidermal pigmentation will appear darker than the deeper dermal pigmentation which will appear lighter under the lamp. It is the epidermal pigmentation that is easiest and fastest to treat.
Treatments for PIH
There are a variety of medications and procedures in addition to photo protection that can safely and effectively treat PIH however, it is important to always be mindful of the potential of the treatment you choose to exacerbate PIH by causing further irritation, so caution must be taken.
– Since sunlight may cause further darkening, specialists recommend to protect yourself from sun exposure and using a broad-spectrum sunscreen containing zinc and titanium dioxide (SPF 15 or more).
– Laser treatments and intense pulsed light therapies (IPL) are often prescribed to treat pigmentation, however if misused they may cause further irritation and worsening PIH in darker skin types.
– While bleaching creams are available over the counter (0.5–2% hydroquinone in the US and stronger, there is growing concern over its safety. In fact, hydroquinone is banned for use in non-prescription cosmetics in Europe and the Food and Drug Administration (FDA) is considering removing them from the market, the ruling is still pending. Side effects of Hydroquinone even with short term use in 1 to 2% include permanent pigment loss (hypo-pigmention) of the surrounding normal skin (‘’ halo effect”) or in extreme cases (exogenous ochronosis) where homogentisic acid accumulates within the dermis causing hyperpigmentation and papules.
– Cortisone creams should not be used with limitation and only under the supervision of a doctor, as they thin the skin with prolonged use, rendering it more sensitive and prone to PIH.
– Cosmetic camouflage (such as cosmetic foundations and concealers) can be helpful in disguising the difference in skin colour.
– Continued research and demand for newer, more effective depigmenting agents is fueling innovation in topical treatments with less side effects. The Uniq White complex, a patented formulation, is specially designed to respect sensitive skin by excluding known controversial and irritating ingredients for a safer more effective skin treatment. Your doctor will do a diagnostic and skin analysis to ensure your suitability.
If the discoloration is distressing to you or you have a chronic skin condition leading to the darkening, seek medical advice. Also see your doctor if you notice a general change in skin color without any obvious explanation.
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