How effective is azelaic acid treatment for post-inflammatory hyperpigmentation?

Post-inflammatory hyperpigmentation develops after inflammation or injury, such as acne, eczema, irritation, or a procedure. Azelaic acid can calm inflammatory activity and interfere with the pigment-making process that leaves a brown or grey mark. It does not remove the original trigger, so new acne or irritation can create additional marks while older ones are fading.

Improvement is gradual and varies with the depth and colour of the pigment, skin sensitivity, and whether inflammation has stopped. A darker or greyish mark may need a different assessment because pigment can sit deeper in the skin.

Use the prescribed or labelled amount on clean, dry skin and introduce it as directed. Apply moisturiser if your skin feels dry or stings, and pause to seek advice if burning, swelling, blistering, or a persistent rash develops. Use broad-spectrum sunscreen and protective clothing on exposed skin; otherwise daylight can keep pigment active and make progress harder to judge. Avoid adding several irritating exfoliants or lightening products without professional guidance.

Arrange a dermatology review if a mark changes quickly, bleeds, becomes painful, develops a new raised area, or does not match the pattern of a fading post-inflammatory mark. Seek advice for severe irritation or swelling after application. A clinician can check whether active acne, dermatitis, infection, or another pigment condition is maintaining the colour before changing treatment.

Ask what caused the pigmentation, how often to apply azelaic acid, which other products to avoid, how to protect your skin from daylight, and when the mark should be reassessed if it is not changing.