Post-traumatic hyperpigmentation: Laser treatment or not ?

Post-traumatic hyperpigmentation (PTH) is a common symptom after skin injuries in Asians. PTH occurs on scars or skin following acute inflammation. PTH is classified into the following three conditions based on the pigmented lesions : an increase of epidermal melanin due to the activation of epidermal melanocytes after inflammation, incontinentia pigmenti histological, and dermal implantation of foreign substances known as a "traumatic tattoo". LLLT and LED irradiation are effective methods for controlling skin inflammation. The increase in epidermal melanins. known as basal hyperpigmentation. gradually disappears within 6-12 months. To shorten the treatment period, topical bleaching ointments such as hydroquinone. tretinoin, and vitamin C as well as IPL/long-pulsed alexandrite laser treatments are available. In the case of incontinentia pigmenti histological, which involves chronic inflammation in the skin, the basement membrane is partially destroyed and epidermal melanins are "dropped" into dermal lesions. These dropped melanins are digested by macrophages, which remain as melanophages in the dermal lesions for several years, and so this type of dermal pigmentation does not disappear spontaneously. Therefore, Q-switched lasers are used for the selective treatment of dermal hyperpigmentation. For the treatment of PTH, personalized, appropriate therapeutic planning based on a precise diagnosis is important.