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A mysterious patch of white hair on a young boy’s scalp

Joe R. Monroe, PA-C, MPAS

The author practices in the dermatology department of the Warren Clinic, Tulsa, Oklahoma, and is the founder and past president of the Society of Dermatology Physician Assistants. He has indicated no relationships to disclose relating to the content of this article.

A 5-year-old boy is referred to the dermatology department of our clinic for evaluation of a patch of white hair on his right parietal scalp that has been present almost since birth. His parents say that he is otherwise healthy. There is no family history of this condition.

On physical examination, the patch of white hair feels normal and there is no change in the skin under the patch (see Figure 1). Examination of the child’s face indicates that his eyes, brows, and nose are normal in structure. Both irises are exactly the same color. There are no unusual changes in skin pigment anywhere on his body. He is of normal height and appropriate intelligence, and he has no apparent hearing deficit.

The patch of white hair is called

Vitiligo
Leukoderma
Nevus sebaceous
Poliosis

Discussion

The correct term for a circumscribed area of white hair is poliosis. While not a disease, poliosis can be caused by many pathologic conditions, including vitiligo and nevus sebaceous. It can be found on any hair-bearing skin and at any age, depending on the actual cause.

Vitiligo, thought to be an autoimmune process, manifests as complete, localized loss of pigment in skin or hair. Vitiligo is not the correct diagnosis for the patient in this case because no other manifestations of this condition were seen.

Nevus sebaceous is a congenital papule or plaque found on the scalp, face, or neck of children or adults that is occasionally accompanied by localized poliosis. This patient had no such papule or plaque.

Leukoderma, an acquired cutaneous depigmentation, is caused by contact with certain chemicals or dermatosis. Because leukoderma does not affect hair color, it would not be the correct diagnosis in this case either.

Treatment Poliosis itself is not treated, but if an underlying condition is causing the condition, that condition may require intervention. The discovery of poliosis in a child requires investigation since some rare but nonetheless serious conditions can be causing the poliosis. The possibilities include tuberous sclerosis, which can appear as “mountain ash leaf” spots, or depigmented macules typically seen on the trunk; Waardenburg’s syndrome, which can manifest as deafness and hypertelorism; and ocular albinism, which can be indicated by generalized hypopigmentation.

Most cases of poliosis appear idiopathic but may be secondary to some past inflammatory event, such as alopecia areata or even simply trauma. This patient had none of these associated findings. The cause of this patient’s poliosis was not determined; therefore no treatment was indicated.