Posted tagged ‘skin’

Nevus sebaceous – what we don’t know about their management

June 5, 2017

The Pediatric Insider

© 2017 Roy Benaroch, MD

Trupti sent in a quick question, to which I’ve written an honest but worthless answer. Such is medicine, sometimes. But honestly is always the best policy, right?

“Hi Dr. Roy, can you please shed more light on nevus sebaceous and its management?”

Nevus sebaceous – also called “nevus sebaceous of Jadassohn” or “sebaceous nevus” – is a fairly common skin patch. And by fairly common, I’d say I see a new one of these on my patients maybe once a year. They’re usually found on the head or neck, often noted at or shortly after birth. I’ve also heard they can arise later, but I don’t think that’s too common. They look kind of waxy and bumpy, with a yellow-brown or yellow-pink color, and if they arise in the scalp they stand out a little more because they don’t grow hair.

Really, the only management decisions are whether to have the removed, and when. Do they have to be removed? The answer here is a clear and definite “maybe.”  Derm textbooks and many docs who trained in the past will tell you that many of these will turn into cancer, so they ought to be lopped off, excised, and fully extirpated with extreme prejudice. This is based on older studies that found cancer rates up to 10-30% — and, yes, if that were true I’d say get them off. But more-recent studies since the 1990s have found much lower rates of cancer, perhaps less than 1%. Those older studies had mis-classified pathology findings as basal cell carcinomas, when in retrospect they were benign. We honestly do not know exactly how many of these will develop into cancer over a child’s lifetime, though cancerous transformation certainly isn’t common when kids are young.

There still isn’t a consensus in the dermatology literature about this. Though some authors recommend prophylactic removal because of this cancer risk, others do not. Here’s a table from a 2012 review – note that newer recommendations tend to be less surgery-happy, but they’re still all over the place:


OK, so that’s clear now. Another reason to consider removal is cosmetic – and especially if one of these is on the face or the side of the neck, you’d probably want to consider removal for your child. That’s something to talk w/ a plastic surgeon or dermatologist about. Removal of one of these will always leave some kind of scar, and you want an honest assessment of what it will look like afterwards – there’s no such thing as a no-scar removal.

As for when to take them off, well, there’s no consensus about that either. In early childhood they’re smaller, so hypothetically easier to remove, but it’s harder to use safe local anesthesia in younger children. You could wait to see how it develops through adolescence, but if it gets much bigger a more extensive, possible multi-staged, procedure is going to be needed.

Bottom line: we don’t know if these should be taken off, or the best time to do the procedure. I know, clear as mud – aren’t you glad you asked, Trupti? You should talk with your child’s doc, and get the opinions of a few knowledgeable plastic surgeons to help make the best decision. Good luck!


Stretch marks in teens

October 2, 2014

The Pediatric Insider

© 2014 Roy Benaroch, MD

MJ sent me a photo of her teenage son’s back, and asked “Could these be stretch marks from growing so fast?”


That’s exactly what I think they are, MJ. I see shallow, linear, parallel marks that lie across the back, perpendicular to the long axis of growth. The doctor-word for this is “striae atrophicae”, or just striae or stria. Everyone else calls them stretch marks.

Women who’ve been pregnant know all about stretch marks, but other people get them too. Teenagers who are growing taller rapidly often get them, as can anyone who gains excessive weight (especially if the weight comes on quickly.) We most commonly see normal striae on the shoulders, abdomen, hips, buttocks, thighs, and breasts.  In time, these striae in teenagers gradually fade, and lose their reddish or purplish color.

There are some other health conditions that can cause a lot of striae, often appearing in unexpected places where there isn’t much stretching of the skin. People with Marfan Syndrome sometimes have quite a bit of stretch marks (they’re also usually tall and lean and gangly, with long arms and flexible joints.) Using oral or high potency topical steroids can predispose to striae, as can Cushing Syndrome (excessive adrenal steroids—very rare in kids, but when you see it they’ve got a round face and stop growing taller.) Children who’ve undergone chemotherapy or who’ve experienced other major illnesses sometimes develop striae. Most striae, though, are just a normal part of growing up.