Although they work in more or less the same way, PPD is a more aggressive ingredient. Semi-permanent and permanent hair colourings usually use either p-Phenylenediamine (PPD) or Toluene-2,5 Diamine Sulfate to activate the colouring pigments. It is also the primary cause of allergic reactions in hair colourings. PPD is commonly used in many traditional and 'natural' hair colour formulas. If you're looking into switching to a safer, more natural hair colour product, you're likely to encounter references to the chemical compound p-Phenylenediamine (often abbreviated PPD). What's the Difference Between PPD, Toluene-2,5 Diamine Sulfate, and Phenylenediamines? Clinical cases in skin of color medical, oncological and hair disorders, and cosmetic dermatology. Sunlight can cause PIH to darken, so it is important to utilize protection from the sun (sunscreen, sun-protective clothing) on the areas involved. In addition, certain treatments can speed up the process, such as topical hydroquinone, retinoid, corticosteroid, azelaic acid, glycolic acid, kojic acid, along with procedures such as microdermabrasion and light chemical peels.ĭermal PIH is more difficult to treat and may require more aggressive therapy such as chemical peels and/or laser surgery, which include a risk of worsening the pigmentation. For effective long-term treatment of PIH, it is essential to treat the underlying skin problem that is leading to the discoloration. Post inflammatory hyperpigmentation can take months to years to fully clear. Mixed and dermal melasma are very difficult to treat due to the presence of deeper pigment. Epidermal PIH is the most amenable to treatment with topical regimens.

This classification is based on the depth of hyperpigmentation in the skin visualized on clinical exam or with the use of Wood’s lamp examination or biopsy (removal of skin tissue for examination). PIH can be epidermal (top layer of skin), dermal (deeper layer of skin) or mixed. Skin problems that often result in PIH include acne, burns, eczema (atopic dermatitis), allergic reactions, infection, insect bites, lichen planus, pseudofolliculitis barbae, and psoriasis. Skin of color has more pigment (melanin) so there is more of a chance of PIH with certain skin problems. Irritation or damage to the skin, can lead to post-inflammatory hyperpigmentation. It is very common in skin of color with over 65% of African Americans experiencing symptoms. The skin involved turns tan, brown, or purple, which brings about the term hyperpigmentation (more color). Post-inflammatory hyperpigmentation (PIH) occurs after there is damage or irritation to the skin. Post-Inflammatory Hyperpigmentation (PIH)

Abbreviation for hair color