What is vitiligo?
Vitiligo is an acquired skin disorder characterized clinically by white or very light colored spots on the skin. Under the microscope, vitiligo causes the destruction of melanocytes, which are the cells that produce pigment or color in the skin.
What do vitiligo spots look like?
The typical vitiligo spot is chalk white in color and can vary from the size of a pencil eraser to lesions covering an entire leg or larger. The spots may be round, oval, linear or polygonal in shape. They usually progress gradually to other parts of the body, although some individuals have rapid growth of spots.
Who gets vitiligo?
Vitiligo appears to affect about 0.5% to 2% of the population. It occurs in all races with similar prevalence, although darker-skinned individuals have more noticeable lesions, because of the contrast between affected and unaffected areas of skin.
What causes vitiligo?
The exact cause of vitiligo is unknown. Current research points to an autoimmune cause of vitiligo, in which the body’s immune system mistakenly recognizes melanocytes as foreign and destroys them. Occasionally, an event such as a sunburn surgery or even emotional distress may trigger the condition. Genetics plays a role and about 30% of affected individuals may report a positive family history (i.e. aunt, uncle, cousin, grandparent). Fortunately, it is rare for children of an affected individual to develop vitiligo themselves. This happens in less than 10% of parents.
Not all white spots are vitiligo
It is important to confirm the diagnosis of vitiligo by visiting a physician, since white spots can occur from yeast infections, eczema and other causes. The physician will examine the skin and sometimes use a special blue light called a Woods lamp to see the lesions better, especially in fair skinned persons. About 15% of patients with vitiligo will develop thyroid disease, therefore, screening tests for thyroid disease should be considered in all vitiligo patients. Other autoimmune diseases associated with vitiligo are diabetes mellitus and pernicious anemia, but they are much less common, occurring in (less than 1% of patients. Individuals with vitiligo may have white hairs, moles surrounded by white skin and small patches of hair loss. Fortunately, vitiligo is not associated with a higher risk of skin cancer or internal cancers.
Laboratory studies often performed to detect diseases associated with vitiligo include:
- Thyroid profile: especially TSH (to rule out thyroid disease)
- Fasting blood sugar or hemoglobin A1C (to rule out diabetes)
- Complete blood count (to rule out pernicious anemia)