Diagnosing Vitiligo

Vitiligo is a skin condition that causes white patches to appear on the skin. These patches occur because the cells that make skin pigment, called melanocytes, are destroyed, leaving areas of skin with no pigment at all. Vitiligo can affect skin on any part of the body—even the inside of the mouth and the scalp, possibly affecting hair color—and white patches may grow in size or spread to other parts of the body over time. 

This condition is not painful or itchy, but the appearance of white patches may make a person feel self-conscious, especially if vitiligo affects skin in visible places such as the face, arms, or legs. Vitiligo is more noticeable in people with a darker skin tone, but because the affected areas of skin are completely devoid of pigment, vitiligo can sometimes be visible even in people with very fair skin. The condition poses no threat to a person’s overall health, and the decision to pursue treatment is a personal one.

Dermatologists at NYU Langone understand that changes in the appearance of skin can affect social and professional interactions. Our specialists have the experience and resources to identify vitiligo and determine whether an underlying condition should be addressed.

Causes and Types of Vitiligo

Vitiligo can affect males and females of any age or skin tone. It often first appears when people are in their 20s. Depigmented spots may stay confined to specific areas—commonly on the face, hands, arms, feet, and lips—or they may affect large areas of skin or even the entire body. The texture of affected skin remains the same as surrounding skin. 

There are two common types of vitiligo: segmental and generalized. In segmental vitiligo, depigmented patches appear either on one area on the left or right side of the body. In generalized vitiligo, depigmented patches appear almost symmetrically on both sides of the body and may spread to other areas over time. This is the most common type of vitiligo. Rarely, a person may develop occupational vitiligo, in which depigmentation is due to exposure to certain industrial chemicals, such as those used to make rubber.

There is no known cause for segmental and generalized vitiligo, though research suggests these conditions may be the result of an autoimmune disorder that causes the body’s immune system to mistakenly attack melanocytes. People who have other autoimmune diseases, such as hypothyroidism or alopecia areata, may have an increased risk of developing vitiligo, and people with vitiligo may have an increased risk of developing another autoimmune disease. 

Vitiligo may also have a genetic component and run in families.

Diagnostic Tools

Our dermatologists often diagnose vitiligo based solely on a physical examination. If doctors need more information about how the condition affects your skin cells, they may suggest a skin biopsy or blood test. 

Medical History

Information about your past and current health may help your dermatologist confirm a diagnosis. He or she may ask you when white or lighter patches of skin first appeared and whether they affect several parts of the body or remain in one location. Your doctor may also ask if you have been diagnosed with an autoimmune disorder, such as hypothyroidism or type 1 diabetes, and if any of your family members have a history of vitiligo or an autoimmune condition. 

Physical Examination

Your dermatologist performs a thorough physical examination to determine if vitiligo is affecting your skin and, if so, to identify the type. He or she visually examines your skin from head to toe, noting the places in which depigmentation appears and whether patches appear on one or both sides of the body, symmetrically or in random patterns, and whether they affect only skin exposed to sunlight or areas that are less exposed, as well. 

If your skin is very fair, it may be hard to distinguish the depigmented patches caused by vitiligo. In these instances, a dermatologist may use a handheld tool called a Wood’s lamp to shine ultraviolet (UV) light on your skin. A patch of skin that is truly depigmented has a different appearance under the UV light than unaffected skin. 

Skin Biopsy

Your dermatologist may need more information about your skin cells to confirm a diagnosis of vitiligo. A skin biopsy can definitively tell the difference between missing melanocytes, which indicates vitiligo, and melanocytes that are malfunctioning for another reason. Vitiligo is diagnosed only if these pigment-producing cells are missing. 

Very rarely, a form of skin cancer called hypopigmented cutaneous T-cell lymphoma may cause white patches due to malfunctioning melanocytes. A skin biopsy can rule out this possibility. 

Blood Test

Rarely, your dermatologist may recommend a blood test to get more information about a possible autoimmune response related to vitiligo. The blood test is done in the office and a doctor or staff member calls you with the result in five to seven days.