Case study: What would cause a shock of stark white in the center of this child's otherwise black head of hair? Your Dx?
A 14-month-old boy is seen for a “cold.” He also has a white forelock. The white forelock was noted sometime between 6 and 9 months of age. His pediatrician was alertâ¦a hearing test was performed and it was normal. There are no relatives who have white forelocks or hearing loss.
Physical examination: White forelock. Areas of sharply demarcated hypopigmentation with islands of normal pigment within are noted on torso, legs. Normal neurologic examination. No nystagmus. He is able to hear and his speech development is normal.
A closer look: Note the white forelock and a white patch on his lower abdomen. The interpupilary distance was normal. There was no displacement of the inner canthi.
And, closer: Underneath the white forelock there is a macular area of skin that is without pigment. There is no scale present.
Putting the pieces together: First, consider: “Is the area of depigmentation congenital or acquired?” This is an important point. Next: The child’s hearing is normal. This is an important feature, too.
Pertinent Positive/Negative Findings: No hypertelorism. No displacement of the inner canthi (dystopia canthorum).
Differential diagnosis for white forelock: Vitiligo. Fungal infections. Poliosis. Waardenburg syndrome.
Differential diagnosis for white forelock: Vitiligo: but this is an acquired disease. Fungal infections: but this is not congenital. Poliosis: white hairsâ¦but in this case there is depigmented skin, too. Waardenburg syndrome: this is a possibility, but hearing loss is part of the syndrome as is dystopia canthorum.
Answer: Piebaldism. Has been called partial albinism, but that term is confusing and has been discarded.Congenital leukoderma that favors the trunk, extremities, mid-forehead, and frontal scalp. Normal islands of pigment are found within the areas of leukoderma. Pathogenesis: mutation of a protein product (proto-oncogene KIT and SNAI2) on chromosome 4 that affects tyrosine turnover. Autosomal dominant, but can be a spontaneous mutation.
Piebaldism: Histology: electron and light microscopy show a complete absence of melanin and melanocytes in the epidermis and hair bulbs.
Another area of consideration: The areas of absent pigmentation are subject to more severe sunburn. Therefore, as with all patients, we should discuss sunscreen usage.
If you were set on Waardengurg syndrome: Classic Waardenburg syndrome presents with the following (in decreasing order of appearance): dystopia canthorum; broad nasal root; synophrys (confluent eyebrows); heterochromia irides; congenital deafness; leukoderma.
What about treatment? Usually none, but...Patients who are self-conscious about appearance may benefit from: Dermabrasion of areas of depigmentation followed by application of melanocyte-enriched cell suspensions. Melanocyte transplant by shaving off epidermis and replacing it with shaved-off skin from another site. Suction epidermal grafting or full-thickness punch grafts; a combination of these methods may be required and can be augmented with UV light therapy. Less invasive methods for improving appearance can be achieved with cosmetic camouflage techniques.
Genetics Home Reference, National Library of Medicine, National Institutes of Health. Piebaldism. Accessed August 12, 2015 and available at: CLICK HERE.Medscape.com. Piebaldism. Accessed August 12, 2015 and available at: CLICK HERE.Rocha de Hollanda T, Estefan J, Boleira M, Ribeiro M. Human piebaldism. J Am Acad Derm. 2013;68(Suppl 1):AB98. CLICK HERE.
A young boy is brought in by his mother because he has a cold. He also happens to have a shock of stark white in the center of his otherwise black head of hair. This gets you thinking--but not about the cold. Our slides give you a closer look at the case; what's your diagnosis?