What should you know about PIH after laser?

Post-inflammatory hyperpigmentation, or PIH, is extra pigment left behind after the skin has been irritated or injured. After laser treatment, it may look like tan, brown, grey-brown, or darker patches in the treated area. The colour can become more noticeable as redness and swelling settle, so an early change does not by itself show the final result.

The risk is influenced by the laser settings, the treatment depth, your natural skin tone, recent sun exposure, and how the skin heals. Picking flakes, rubbing, heat, and ultraviolet or visible light exposure can sustain inflammation and deepen the colour. PIH is different from an infection or a burn, although those problems can also cause colour change and need assessment when other warning signs are present.

Follow the aftercare plan from the treating clinician, keep the area gently cleansed, and use the recommended bland moisturiser or barrier ointment. Do not scrub, peel, or remove crusts. Avoid introducing exfoliating acids, retinoids, bleaching products, fragranced products, or home remedies until the skin surface has recovered and your clinician says they are suitable.

Protect the area from sunlight with shade, clothing, and the sunscreen recommended for your healing stage. Reapply it as directed when the skin can tolerate it. Arrange a review before starting a pigment treatment: a clinician may first check that the barrier is intact and may then consider a prescription product or another approach based on your skin and the original laser treatment. Do not repeat laser over darkening without professional advice.

Contact the treating clinic promptly if pain is increasing, redness is spreading, the area feels hot, blisters or pus appear, or the skin is opening rather than closing. Fever or feeling unwell also warrants medical advice. Seek urgent care for severe swelling involving the eyes or trouble breathing. Even without these symptoms, book a review if the colour change is worsening, very uneven, or not behaving as expected during healing; the clinician can distinguish PIH from other post-treatment complications.

Ask which laser settings and healing changes may have contributed to the darkening, whether your skin barrier is ready for any pigment treatment, and which cleanser, moisturiser, and sunscreen fit your current stage. It is also useful to ask when the clinic wants to reassess the area and what signs should prompt an earlier appointment.