What should you know about dark flat spot on skin?

A mark left after a rash, bite, pimple, burn, or irritation may be [Post-Inflammatory Hyperpigmentation](/conditions/post-inflammatory-hyperpigmentation/). Symmetrical patches on the face can occur with [Melasma](/conditions/melasma/), while long-term sun exposure can contribute to [Sun Spots](/conditions/sun-spots/). A flat patch with fine scale, especially on the trunk, may be [Tinea Versicolor](/conditions/tinea-versicolor/). Colour alone cannot confirm the cause, and more than one process can occur on the same skin.

Photograph the spot in steady lighting and record its location, border, texture, and any change. Use broad sun protection, avoid picking or rubbing, and stop any product that stings or causes a rash. Do not use strong bleaching agents or prescription creams without advice. Once the cause is clear, a clinician may discuss [Chemical Peel](/treatments/aesthetic-procedures/chemical-peel/), [Skin Brightening Treatment](/treatments/aesthetic-procedures/skin-brightening-treatment/), or [Picosecond Laser Treatment](/treatments/laser-and-energy/picosecond-laser-treatment/); these are not interchangeable and may worsen pigment in some skin types.

Arrange prompt assessment if the spot is new and changing, has an irregular edge or varied colour, bleeds, crusts, becomes painful, or fails to heal. Seek urgent care for rapid swelling, severe pain, blistering over a large area, or signs of infection. A clinician should examine any persistent mark that cannot be explained by a recent injury or inflammation.

What is the most likely cause of this flat spot? Does it need magnified examination or testing? Which treatment suits my skin tone, and how will we reduce the risk of irritation or darker pigment afterward?