I was recently scanning an online forum about pediatric health concerns. (What can I say? I sometimes need inspiration.) There was one thread within the forum that was significantly longer than any other. Parent after parent posted about how they had noticed a knot on their infant or toddler. This concern parallels what I see in practice. An unexplained knot on the head is a common reason parents bring their child to be evaluated.
The first thing that comes to parents minds is that the lump represents something bad, like cancer. Fortunately, these lumps are almost always nothing to be concerned about. Worst case scenario is some lumps (cysts) may need to be surgically removed, but this is rare.
These are the things that parents notice:
- Lymph nodes. By far these are the most common lumps that parent notice and worry about. Most parents realize that lymph nodes can be found in the neck, but do not know that they are also found around the ears and at the back of the skull. A pea-sized, rubbery knot beneath the skin is nothing to worry about. Often these are found in young infants (2 months old), leading to an office visit (if you have an infant, feel the back of his skull a few inches above the neck… you see what I mean?). Healthy lymph nodes fluctuate in size, they grow and they shrink. Bad lymph nodes keep growing and are not subtle. If a lymph node is the same size that it was a month ago, it is healthy. A lymph node needs to at least the size of a marble before I even bat an eyelash at it. Even then, I will simply recheck it in a few weeks to make sure it is not continuing to grow.
- Congenital cysts. There are certain locations on the head that children can be born with a congenital cyst. These can sometimes get infected and lead to problems. However, some people could go their whole life with a cyst without having any problems. Typical locations are in front of the ear (preauricular cyst), in the front middle of the neck (thyroglossal duct cyst), or the sides of the neck (brachial cleft cyst). Cysts in these locations may also have dimples or tunnel from the skin down to the cyst. Occasionally, these will need to be surgically removed. Other times, they can be simply observed for problems. (Your beloved, middle aged, blogging pediatrician has a thyroglossal duct cyst. It has never caused me any problems and is not very noticeable, so I have just lived with it.)
- Dermoid cysts. I have probably seen 3 to 4 kids in my career with a cyst in their eyebrow. These are typically located at the part of the eyebrow closest to the temple. They are rubbery and the size of a pea or lima bean. Because these can sometimes rupture due to trauma and cause a strong inflammatory reaction, they are often surgically removed.
- Bony knot on an infant’s skull. Infants will often have swelling or bruising of their skull from delivery. These areas of injury will sometimes calcify leading to a hard bony knot on the skull. This is definitely something parents notice and worry about. This calcified area is not dangerous and tends to remodel and go away as the skull grows, typically within several months.
These lumps certainly generate a disproportionate amount of anxiety relative to the true risk that exists from them. If the lump is small and difficult for someone else to find, the chance it represents something that needs to be urgently evaluated is probably zero. Things that make me concerned are typically blatantly obvious. In other words, I can see it from across the room. Otherwise, watchful waiting is probably going to be the safest, least invasive and most cost-effective approach to lumps and bumps on the head.
Michael Gonzalez is a pediatrician who blogs at The Anxious Parent.
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