There have been many attempts to classify different types of vitiligo with varying degrees of success. The results are often conflicting and rather confusing. Two major forms are generally recognized:

• Bilateral. This is the more common form in both children and adults and may be referred to as vitiligo vulgaris. Macules (patches) of depigmented skin occur evenly on both sides of the body.
  
  
• Unilateral. Also called segmental, it occurs more often in children than adults. This form of vitiligo usually does not cross the middle part of the body. In fact, macules often stop abruptly at this point.

These two forms are very broad in scope. Three more specific types are usually recognized: generalized, localized and universal.

Generalized is the most common type of vitiligo and includes:

• Vulgaris. Scattered, widely distributed macules on both sides of the body.
  
  
• Acrofacial. Macules affecting the extremities (e.g., hands, feet) and the face.
  
  
• Mixed. Macules occurring in both localized and generalized patterns.

Localized include the following:

• Focal. One or more macules in a single area.
  
  
• Unilateral (segmental). One or more macules on one portion of the body, stopping abruptly at the midline.
  
  
• Mucosal. Macules affecting the mucous membranes (e.g., inside the mouth).

Universal is the complete or nearly complete depigmentation of the skin over the entire body. This type of vitiligo is the rarest.

All of these types may involve no functioning melanocytes (cells that produce melanin, the substance responsible for skin color) in the skin at all. In other cases, melanocytes are still present and identifiable in the macules but either do not function or function in a reduced capacity.

There are many variations of vitiligo, including:

• Vitiligo capitis. Vitiligo macules on the scalp. Hair that grows from the affected area lacks pigmentation. Many cases of spontaneous graying in patches of hair have been attributed to this.
  
  
• Koebner phenomenon. Sometimes, vitiligo develops at sites of specific trauma (e.g., cuts, burns, abrasions). This is known as Koebner phenomenon and is observed in both bilateral and unilateral forms.
  
  
• Trichrome vitiligo. In this variation, depigmented macules are bordered with a zone of a uniform, intermediate hue. Melanocytes in this area are decreased, but not absent.
  
  
• Blue vitiligo. Vitiligo with blue colorations, generally developing in areas of darkened skin following inflammation.
  
  
• Vitiligo ponctué. An unusual form of vitiligo with small confetti-like or tiny, discrete macules that may occur on otherwise normal or unusually darkened skin.
  
  
• Inflammatory vitiligo. An uncommon form of vitiligo with macules surrounded by a border that is inflamed and may be itchy.
  
  
• Alezzandrini syndrome. A very rare disorder characterized by depigmentation of the scalp hair, eyebrows and eyelashes, vitiligo macules on the forehead, nose, cheeks, upper lip and skin and vision impairment. This is usually unilateral, with all characteristics occurring on the same side.