How effective are topical calcineurin inhibitors for hypopigmentation?

Hypopigmentation describes skin that is lighter than nearby skin, not one single diagnosis. It can follow eczema or another inflammatory rash, occur with vitiligo, appear after injury, or reflect an infection or medication effect. A calcineurin inhibitor quiets certain immune signals in the skin, so it is most relevant when inflammation is contributing to the colour change. If the area is no longer inflamed, treatment may not recolour it. A clinician may examine the border, surface and distribution, and may use a light examination or other tests when the cause is unclear.

Do not apply the medicine to an unexplained pale patch until a clinician has confirmed the diagnosis, especially if the area is enlarging or has scale. Follow the prescribed frequency and use a gentle cleanser and moisturiser. Protect the surrounding skin from sun so contrast is less noticeable and the area is less likely to burn; choose the sunscreen and reapplication routine advised for your skin. Record whether itching, redness or scale changes before the colour does. Avoid harsh bleaching products, exfoliation and unapproved combination creams, which can make colour differences harder to assess.

Book an assessment for a new, spreading, sharply bordered or repeatedly returning light patch. Seek earlier advice when there is pain, significant itch, scale, blisters, hair whitening or involvement around the eyes, mouth or genitals. Prompt review is also sensible if several areas appear or if treatment causes intense burning, swelling, crusting or a new rash. Urgency is based on these changes and symptoms, not on the presence of a light patch alone.

Ask what is causing the colour loss, whether inflammation is still active, what change would show that treatment is working, and when the diagnosis should be reconsidered. Also ask about sun protection, safe moisturisers and whether another treatment is needed for pigment recovery.