How long does hydroquinone treatment take to work for post-inflammatory hyperpigmentation?

Post-inflammatory hyperpigmentation appears after skin has been irritated or injured, such as after acne, eczema, a burn or another rash. Hydroquinone can reduce new pigment formation, but it does not stop the original inflammation. If spots continue to form, the overall colour may seem unchanged even while older marks are fading.

Pigment deeper in the skin often changes more slowly than a surface mark. Read about [Post-Inflammatory Hyperpigmentation](/conditions/post-inflammatory-hyperpigmentation/) and [Hydroquinone Treatment](/treatments/medical-dermatology/topical-hydroquinone-therapy/).

Use hydroquinone only as prescribed and address the condition causing ongoing itching, spots or irritation. Avoid picking, squeezing, harsh exfoliation and unplanned peels. Daily broad-spectrum sunscreen, shade and clothing that covers the area can reduce renewed darkening, especially after inflammation.

Take a baseline photograph and compare it with later images in similar light. A clinician can review progress after the agreed interval and decide whether to continue, pause or change treatment.

Arrange medical advice if the rash, acne or wound is still active, or if redness, pain, swelling, crusting or discharge develops. Report strong burning, blistering, persistent scaling or unusual blue-black darkening after application. A changing lesion should be examined rather than treated repeatedly at home.

Is the inflammation fully controlled? How deep does the pigment appear? Which products should I avoid while the skin heals? What improvement should we look for at the next review, and what is the alternative if it remains unchanged?