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Vitiligo
Vitiligo is an autoimmune disease in which cytotoxic T cells destroy melanocytes, producing chalk-white, sharply defined macules that stand out under a Wood lamp; it is linked to other autoimmune diseases, mainly thyroid disease.
Why it matters in the exam
The exam shows a child or young adult with symmetric white macules around the mouth, eyes, hands and knees, and the question separates vitiligo from pityriasis versicolor (fine scale and fungi on scraping), pityriasis alba (ill-defined pale patches on the face of an atopic child), post-inflammatory hypopigmentation and nevus depigmentosus. Also asked are the segmental form (unilateral, starts young and stops quickly), the Koebner phenomenon, halo nevus, and treatments: topical steroids and calcineurin inhibitors, NB-UVB, and a topical JAK inhibitor — ruxolitinib cream — approved for vitiligo on the face and body. Remember that active disease shows "confetti" macules and blurred borders, that this is the time to add a short systemic course, and that in very extensive stable disease depigmentation of the remaining skin can be considered. The psychological impact is significant, especially in darker skin, so psychological support is part of treatment. Thyroid function should be checked in every new patient.
Key points
- Vitiligo is an autoimmune disease in which T cells destroy melanocytes, producing completely white, sharp macules.
- A Wood lamp highlights the macules and helps separate vitiligo from pityriasis versicolor, pityriasis alba and post-inflammatory hypopigmentation.
- Vitiligo is linked to autoimmune thyroid disease, so TSH and TPO antibodies should be checked.
- Treatment includes topical steroids and calcineurin inhibitors, ruxolitinib cream and NB-UVB, and in active disease mini-pulse steroids.
- Segmental vitiligo is unilateral, starts young, stops quickly and suits melanocyte grafting when stable.
Summary table
| Aspect | Finding | Meaning | Action |
|---|---|---|---|
| Non-segmental vitiligo | Symmetric white macules around orifices, on the hands, knees and elbows | The common form; unpredictable course | Topical steroids or tacrolimus, NB-UVB, ruxolitinib cream |
| Segmental vitiligo | Unilateral macules along a segment, young age, white hair within the patch | Spreads quickly then stops; responds less to phototherapy | Early topical treatment; melanocyte grafting when stable |
| Active disease | Confetti macules, Koebner phenomenon, blurred borders | Rapid spread | Oral mini-pulse steroids (OMP) and NB-UVB |
| Associated diseases | Autoimmune thyroid disease, type 1 diabetes, pernicious anaemia, alopecia areata | Raised risk | TSH and TPO antibodies |
| Differential diagnosis | Pityriasis versicolor, pityriasis alba, post-inflammatory hypopigmentation, nevus depigmentosus | Wood lamp: bright bluish-white in vitiligo | Fungal scraping when there is scale |
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Sources
- European Dermatology Forum / EADV guideline for the management of vitiligo, 2023 — Treatment
- British Association of Dermatologists guideline for the management of vitiligo, 2022 — Topical, phototherapy and JAK inhibitors
- Global vitiligo consensus (VGICC), 2023 — Classification and outcome measures
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.