What is the progression of vitiligo?

Following a selective loss of melanocytes, the cells that produce melanin, the pigment that gives skin its colour, vitiligo is an autoimmune disease that manifests as depigmented patches. However, its progression is far from linear or uniform. In some individuals, the macules appear and remain confined to one or more areas, without notable progression. In others, they spread relatively quickly and affect new parts of the body, sometimes symmetrically. These variations are influenced by genetic, environmental, and immune factors, making each case unique and difficult to predict.

Vitiligo is a disease with an unpredictable progression.

This uncertain nature of vitiligo can be a source of additional anxiety for patients, particularly when the lesions progress rapidly or affect visible areas, such as the face or hands. The progression of vitiligo partly depends on its clinical form. The segmental form, the most common, is also the most difficult to predict. It progresses in flares successively, with phases of progression alternating with periods of stability. Some of these flares can be triggered by external factors, such as stress or skin trauma, a phenomenon known as Koebner. This phenomenon describes the appearance of new lesions at sites that have suffered physical trauma.

Vitiligo can progress in various ways. New white spots may appear on initially unaffected areas, while existing macules can expand and sometimes merge to form large depigmented patches. In some cases, this progression also reaches the hair follicles, causing a whitening of the hair known as leucotrichia. These different phenomena can accentuate the visibility of the affected areas. It should be noted that active vitiligo is characterised by various clinical signs, such as itching or the appearance of small "confetti" depigmentations or clear but not fully depigmented borders around pre-existing lesions.

As previously stated, the progression of vitiligo varies depending on its type. While the non-segmental vitiligo has a rather uncertain progression, remaining localised in some patients and becoming generalised in others (this is then referred to as universalis vitiligo), segmental vitiligo is generally more stable. Accounting for approximately 10% of vitiligo cases, this form has a unilateral distribution and remains confined to a specific area of the skin, often to a dermatome, which is an area of the skin where all the sensory nerves originate from a single spinal nerve root.

It is often preferable and easier to halt the progression of vitiligo when it is in its active phase. This is typically achieved by combining cortisone with UVB phototherapy.