Segmental pigmentation not associated with systemic manifestations, study finds

Key Points

"This is probably the most reassuring reality of the latest research described by M. Hogeling and I.J. Frieden in their study of children with segmental pigmentation disorder (SegPD)," Dr. Treat says.

The research findings dispel the myth that SegPD is more commonly associated with serious systemic manifestations. In fact, they found very few associations with neurologic or skeletal abnormalities.

In the study, published in the June 2010 issue of British Journal of Dermatology, Hogeling and Frieden evaluated 45 children with SegPD.

"It's important for dermatologists to share this information with the parents of their patients because it allays a lot of fears," Dr. Treat says.

"Sometimes people use Google and tend to find all sorts of bad things that can be associated with a disorder," he says. "Dr. Frieden's research is also useful because it can help us avoid some of the big work-ups on kids who are otherwise normal."

Of course, while many patients with patterned pigmentation have no associated anomalies, Dr. Treat says, others can experience extensive involvement.

Evaluation and workup

SegPD is not typically associated with an underlying systemic anomaly and the work-up should be guided by specific signs or symptoms, according to Dr. Treat. In addition, patients with widespread patterned pigmentation, especially those presenting with streaky, thin, Blaschkoid pigmentation, also warrant a work-up.

"Children who have hypopigmented lines that are thin lines are at high risk for hypomelanosis of Ito (HI)," he says.

Research has shown that the earlier in development a genetic error occurs, the more tissues it is likely to affect. As such, the more widespread a pigmentary anomaly, the more likely it is to be associated with underlying systemic abnormalities, according to Dr. Treat.

"The initial work-up of a child with widespread streaky hypopigmentation or hyperpigmentation should include a thorough history, including a birth and family history of any pigmentary, skin, hair or teeth anomalies to identify children with IP (incontinentia pigmenti), and a thorough physical examination," he says.

In cases where pigmentation anomaly is widespread and the child presents in infancy, a referral to neurology for a thorough baseline examination to evaluate subtle delays or motor defects is recommended. In addition, a baseline ophthalmologic exam should be performed.

"Genetic evaluation, including karyotype testing, is also important in children with extensive patterned pigmentation or if other organ systems are associated with the pigment changes," Dr. Treat says.

The good news is that the parents of children who have localized pigmentary changes and are otherwise normal can essentially be confident that it is unlikely there are other conditions involved in their children's health.

Future patterns

Dr. Treat says the biggest step for pigmentary disorders in the future would be for researchers to look at children who have hypomelanosis of Ito with neurologic findings, developmental delays or seizures and figure out how genetics factor in.

"This way, we could have more targeted tests when it really does require a bigger work-up, and know who really does need that follow-up. I think that's really the future of this disorder," he says. "As more and more patients get reported, hopefully we'll find the genes that are involved in HI."

For now, Dr. Treat advises dermatologists to maintain a broad level of knowledge of what healthy childhood development looks like at each stage.

"That helps us know when kids may need more of a work-up," he says. "Do good histories and physicals of children and be aware of localized pigmentary anomalies and what red flags to look for. Also, try to remember that most of these children will be normal."