Diagnosis and tests for vitiligo

Diagnosing vitiligo is usually straightforward for a dermatologist - the examination is the main test, with a few checks to rule out look-alikes and associated conditions.

Clinical examination. The pattern tells most of the story: well-defined milky-white patches with normal sensation in typical sites (face, hands, folds). The doctor maps the distribution (which decides the type), looks for signs of activity (new patches, ill-defined or inflamed borders, injury-site patches), and checks hair within patches for whitening.

Wood's lamp examination. A handheld ultraviolet light in a dark room makes vitiligo patches glow bright chalk-white. This simple, painless test confirms true pigment loss and separates vitiligo from lighter look-alikes like pityriasis alba or post-inflammatory lightening, which glow weakly or not at all.

Tests for associated conditions. Because vitiligo travels with autoimmunity, doctors commonly check thyroid function (TSH) and sometimes thyroid antibodies. Depending on the picture, blood sugar, B12 and other autoimmune markers may be checked. These are not to confirm vitiligo - they screen for conditions that often accompany it.

Skin biopsy (rarely needed). Only when the diagnosis is genuinely uncertain; it shows absent melanocytes.

What is NOT needed: scans, extensive panels, or repeated testing. Vitiligo is a skin-deep diagnosis; expensive workups add nothing.

When to seek review urgently rather than routinely: a light patch that is numb or has lost sweating (needs leprosy ruled out), patches that itch or scale (more likely a fungal or eczematous cause), and any rapidly spreading eruption.

Ayurvedic view (interpretive): classical diagnosis of shwitra relied on inspection of patch character - consistent with the clinical emphasis above, within an interpretive framework of limited evidence. Modern examination plus Wood's lamp remains the standard.

Remember: the dermatologist's eye plus a Wood's lamp is the diagnosis; thyroid screening is the sensible add-on. Numb or scaly patches are a different story - get them checked promptly.