What Is Poliosis?

Poliosis—also called poliosis circumscripta—is a condition in which a patch—or patches—of white hair occur when the rest of the hair color is normal. Poliosis occurs when there isn’t enough melanin in a certain area of hair follicles, leading to a lack of pigment in the hair that grows from those follicles.

Poliosis can occur at any age; some people may have it from birth. It is unclear how common poliosis is, but its associated conditions are generally rare.

This article discusses what poliosis looks like, what causes it, and how to treat it.

Poliosis Symptoms

Poliosis can occur anywhere there is hair on the body, such as:

• The head (when it occurs here, it is commonly called a “white forelock")
• Eyelashes
• Eyebrows

There may be one or several patches of white hair.

Poliosis is different from graying hair. Gray hairs often show up interspersed throughout normally colored hair, while poliosis is a distinct patch of colorless hair among normally colored hair. 

Poliosis, itself, is not serious nor harmful; it is simply a lack of pigment in some hair follicles. But it also may indicate medical conditions that require medical care and follow-up.

What Causes Poliosis?

Poliosis results from a reduction or absence of melanin in affected hair follicles. When there is a lack of melanin, there is a lack of color in the hair that grows from those hair follicles.

A reduction in melanin is due to a reduction in or lack of melanocytes—skin cells that produce melanin. Destruction of melanocytes and a reduction of melanin that then lead to poliosis may indicate a variety of conditions:

• Genetic conditions, such as neurofibromatosis type 1, Waardenburg syndrome, and piebaldism
• Immune or inflammatory disorders, such as alopecia areata, Vogt-Koyanagi-Harada syndrome, and vitiligo
• Some medication use, such as Soriatane (acitretin) and Aralen (chloroquine), though this is rare
• Neoplasms, such as melanoma

Poliosis can occur at any age, depending on the associated underlying condition. For example, a study of pediatric cases of vitiligo—where the peak age of vitiligo onset was about 3 years old—found that all cases also had poliosis. Though some people are born with poliosis from an associated genetic condition, the resulting patches of white hair are not considered birthmarks.

How Is Poliosis Diagnosed?

Poliosis can be seen with the naked eye, but diagnosing the underlying condition requires medical expertise. It’s best to speak to a healthcare provider if you notice a patch of white hair and want to know what’s causing it. Diagnosis can depend on age, including:

• In children, poliosis may indicate a genetic condition, and a healthcare provider will look for other signs of those conditions on the skin.
• In adults, poliosis may lead a healthcare provider to look for benign or malignant melanocytic lesions (which look like large moles). They may also ask for a family or medical history to see if a genetic or inflammatory condition is at play.

Though rare, the use of certain medications may lead to poliosis, and therefore, recent medication use may also be a part of the diagnosis.

Poliosis Treatment Options

There is no permanent treatment for hair affected by poliosis. Because the lack of melanin in the hair follicles causes white hair to grow, dyeing the white patch of hair will only work to cover the poliosis temporarily. The white hair will keep growing back. 

However, for certain associated conditions that may lead to poliosis, treatment of the associated condition may prevent poliosis from occurring. For example, one study found that immunomodulatory therapy and other treatments for people with Vogt-Koyanagi-Harada syndrome prevented the development of poliosis.

What's the Prognosis for Poliosis?

Poliosis is not harmful and usually does not spread. Management generally involves temporary solutions to cover up the white patch. Some people may choose just to let it be.

Summary

Poliosis is a condition in which a white patch of hair appears among normally colored hair due to a lack of melanin. It is different from graying hair and can happen at any age. There are a variety of conditions associated with poliosis, often rare, and diagnosing the underlying cause requires medical expertise.

Poliosis may be prevented through treatment of the underlying condition. It can also be managed with temporary solutions to cover the white patch.