TCA CROSS and pigmentation: what to know

The solution is applied precisely inside depressed scars, where it creates a controlled chemical injury. As the surface heals, pigment-producing cells can become more active, leaving brown or grey-brown marks, especially in naturally deeper skin tones. Less commonly, inflammation can leave a lighter spot.

Colour change is different from the intended textural response. A darker mark does not show that the scar has improved, and a pale area needs monitoring rather than extra treatment at home. Existing melasma, recent tanning, active dermatitis, or a history of dark marks after spots should be discussed before treatment.

Use only the cleanser, protective ointment, and sunscreen recommended by your clinician. Avoid picking crusts, scrubbing, waxing, and restarting retinoids or acids until the surface has recovered. Shade, hats, and consistent broad-spectrum sun protection matter because ultraviolet exposure can deepen post-inflammatory colour.

Tell the clinic about pigment-lightening products, recent tanning, and any medicine that irritates your skin. Ask whether treatment should be delayed while acne, eczema, or another source of inflammation is active. Do not apply household acids or bleaching mixtures to a treated spot.

Arrange a review if a patch continues to spread, becomes painful or blistered, develops discharge, or is accompanied by marked swelling or warmth. Seek prompt advice for rapidly worsening redness, fever, or any eye-area symptoms. A clinician can distinguish expected pigment settling from infection, burns, or another reaction.

Ask how your skin tone and previous pigment response affect the plan, what prevention is appropriate, and when active pigment products can resume. Confirm which colour changes are expected, when they should be photographed, and whether another approach is safer for broad uneven pigmentation.