Understanding Chronic Recurrent Multifocal Osteomyelitis: A Parent's Guide to Symptoms, Diagnosis, and Treatment
You've probably been to several doctors already. Your child has been complaining for months about bone pain, and may even have some swelling. At your last appointment, someone mentioned "CRMO"--and now your head is spinning.
What even is that? Is there treatment for it?
Don't panic! Your neighborhood pediatric rheumatologist is here to chat.
Here, we'll discuss the common symptoms of children with chronic recurrent multifocal osteomyelitis (CRMO). We'll also cover how to navigate the diagnostic process with your child, an overview of common treatments, and community resources.
What is Chronic Recurrent Multifocal Osteomyelitis?
CRMO is a very rare disease and is a type of autoinflammatory bone disease. An autoinflammatory disease happens when the immune system gets confused and starts to cause inflammation in the body.
If bone involvement only includes one area, you may hear the term chronic non-bacterial osteomyelitis (CNO). But, if there are many areas involved, you'll likely hear the term CRMO. For the purposes of this article, we'll use the term CRMO.
CRMO can look like other bone lesions, such as bone infections or even cancer. CRMO is a diagnosis of exclusion. This means your medical team will rule out other things before giving your child an official diagnosis of CRMO.
What Are The Symptoms of CRMO?
The symptoms of CRMO include bone pain and sometimes swelling over the painful bony areas. Symptoms can happen on either the left or right side of the body, but sometimes symptoms can happen on both sides. [1]
Here, we'll review the common symptoms of CRMO to look out for.
Bone Pain
The most common symptom is bone pain. CRMO usually affects the long bones (think thigh bones, shin bones). It's also commonly found in the spine, collar bone, and jaw bone. The pain can be worse at night, and it can be worse when you press on the area. [1]
Swelling
Your child's symptoms may also include swelling over the bony areas that are painful. The clavicle (collar bone) is a common area that's affected, and you may notice one part of the collar bone being more swollen than the other.
Joint Pain and/or Swelling
Sometimes, people with CRMO can also get joint pain with swelling and/or stiffness. This can be close to the areas of bone inflammation, but sometimes the joint pain and swelling are far away from the inflamed bones. [1]
Fatigue
Children with CRMO can feel more tired than usual and may not want to do the things they usually like to do. Though sometimes, this can also be due to bone pain!
Other Related Symptoms
Some children and teenagers may also get a rash, which can be on the palms or soles. The rash usually looks like little pimples. This could be a separate condition called SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis).
Other CRMO patients may have psoriasis, which we'll go over later.
Other symptoms to look out for include:
Canker sores
Abdominal pain
Diarrhea
Bloody poop
Weight loss
These may be signs of inflammatory bowel disease, which some people with CRMO also have.
"Be Sure To Look For"
Finally, you should tell your pediatric rheumatologist if your child has persistent, unexplained fevers, weight loss, or night sweats. These symptoms can be signs of other CRMO "look-a-likes" that need further work-up.
How Is CRMO Diagnosed?
CRMO is a diagnosis made by a pediatric rheumatologist. Your child's care team may also include a pediatric orthopedic surgeon, pediatric infectious disease specialist, and dermatologist, among others.
The diagnostic process includes blood tests, imaging studies, and sometimes a bone biopsy. Let's go over these now.
Blood tests
Blood work is used to look for bone infections, metabolic bone disorders, other types of rheumatic disease, nutritional deficiencies, and screen for blood disorders or cancer.
Imaging Studies
Your child will also have imaging studies. An x-ray is typically the first imaging study that’s done to look for bone damage. However, a more detailed study like an MRI (magnetic resonance imaging) or bone scan is usually needed.
The first MRI usually includes the area where your child has the most pain. However, a whole body MRI is usually needed to screen for other bone lesions. Believe it or not, some active bone lesions may be asymptomatic, meaning your child may not be experiencing pain in those areas at all!
If a whole body MRI can't be done, then your child may have a different bone scan instead. These all look for the same thing, which is bone inflammation, but how the machines work are different. [1]
Bone Biopsy
Depending on the blood tests and imaging results, a bone biopsy may also be recommended to make sure the bone lesions aren't due to infections or cancer. [1,2]
This procedure is performed by an orthopedic surgeon or interventional radiologist. Your rheumatologist should discuss this process with you.
What Other Autoimmune Diseases Are Related to CRMO?
As mentioned before, sometimes children and teens with CRMO can have other types of autoimmune disease. [1] These include:
Inflammatory bowel disease
Psoriasis
Juvenile idiopathic arthritis (JIA)
Some people can also have uveitis, which is a type of eye inflammation that can affect your child's vision. Your provider may recommend screening with a slit-lamp exam to look for this inflammation. This would be performed by an eye doctor.
How Do You Treat CRMO?
Your child's treatment will be managed by a team led by pediatric rheumatology. Treatment of CRMO includes non-steroidal anti-inflammatory drugs (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs), biologic medications, bisphosphonates, and sometimes steroids.
Depending on the severity of the disease, your rheumatologist may recommend one type of medication over another. [3]
Here's an overview of each type of medication:
NSAIDs: Depending on the severity of disease, first line treatment may be non-steroidal anti-inflammatory drugs (NSAIDs). These include medications like ibuprofen, naproxen, celecoxib, or meloxicam. However, if treatment with NSAIDs isn't working, then other medications can be used.
DMARDs: Other treatment options include disease-modifying antirheumatic drugs (DMARDs), such as methotrexate or sulfasalazine. These are commonly used in other rheumatic diseases, too.
Biologic therapies: These DMARDs target very specific molecules that drive inflammation. In CRMO, TNF-inhibitors are commonly used, and include medications like infliximab, adalimumab, or etanercept, to name a few.
Bisphosphonates: These are intravenous (IV) infusions that include pamidronate or zoledronic acid.
Steroids: No, not the kind that make you grow muscles and lots of body hair! The steroids used for CRMO include prednisone–like what is used for an asthma attack.
Some of these medications are immunosuppressive, which help get the immune system under control. Immunosuppressive means lowering the activity of the immune system and is needed in managing many rheumatologic conditions.
While taking these medications, your child needs regular safety monitoring labs.
These medications all have their own benefits, side effects, and risks, and it's important that you discuss these with your pediatric rheumatologist.
Your provider will regularly monitor your child's response to treatment, but keep in mind that sometimes it can take a few months for medications to work. During this time, symptoms may come and go.
Patients with CRMO also need follow-up imaging studies to look for disease activity and treatment response.
Ultimately, each child's case is different. Your rheumatologist will work closely with you to help find the best treatment for your child.
What Are The Outcomes in Children with Chronic Nonbacterial Osteomyelitis?
CRMO/CNO is a form of chronic disease, but children can and do go into remission. It'll be important that you follow regularly with your rheumatologist to watch for disease flares, monitor response to therapy, and make changes to medications as needed.
It's also important to be vigilant for any complications from this bony autoinflammatory disorder. These can include things like bone fracture in areas where there's inflammation, including the spine. [2]
What Support Or Resources Are There For People with CRMO?
It's important to keep in mind that CRMO patients and their families aren't alone! Even though it's a rare disease, other families have gone through similar experiences.
Resources and ways to connect and stay engaged with the community include:
Childhood Arthritis Rheumatology Research Alliance: Families can be involved with workgroups which includes other families, researchers, and providers. There is also a mentorship program that can connect you with other families (with your permission of course!).
CRMO Foundation: An organization started by families navigating CRMO. They provide support and information about CRMO, and also work closely with other organizations to help lead research initiatives and improve outcomes in children and teens with CRMO.
You can also ask your rheumatology team for any local resources or support groups to tap into!
Putting It All Together - You Can Do This!
CNO/CRMO is a rare, autoinflammatory bone disease that most commonly affects children, but teens and young adults can get it, too. CNO/CRMO is a chronic disease that requires regular follow-up with a specialist, as well as medication.
Now that you're armed with a little more knowledge--know that you're not alone, and you can face this. Start by connecting with your medical team (if not already), and don't forget to reach out to community groups when you're ready.
Chin up, friend! You got this.
FAQ
What are the common signs and symptoms of CNO/CRMO?
The most common symptom is bone pain, which may be accompanied by swelling over the area. The pain may get worse if you try to press on it.
What tests are used to diagnose CNO/CRMO?
Your provider will usually order blood work, imaging studies including MRI, and sometimes even a bone biopsy.
Is CRMO treatable?
Yes! This disease can be managed with the help of a rheumatologist. Each person's case may be different, so it's important to follow up with your provider regularly to monitor the disease and response to treatment.
Important Disclosure:
This website offers general information and does not provide medical advice. It is not a substitute for professional medical consultation, diagnosis, treatment, or prevention. No doctor-patient relationship is established through this website. The opinions expressed are solely those of the author and do not reflect their employer's views.
References
Zhao Y, Ferguson PJ. Chronic Nonbacterial Osteomyelitis and Chronic Recurrent Multifocal Osteomyelitis in Children. Pediatr Clin North Am. 2018;65(4):783-800. doi:10.1016/j.pcl.2018.04.003
Zhao DY, McCann L, Hahn G, Hedrich CM. Chronic nonbacterial osteomyelitis (CNO) and chronic recurrent multifocal osteomyelitis (CRMO). J Transl Autoimmun. 2021;4:100095. Published 2021 Mar 20. doi:10.1016/j.jtauto.2021.100095
Zhao Y, Wu EY, Oliver MS, et al. Consensus Treatment Plans for Chronic Nonbacterial Osteomyelitis Refractory to Nonsteroidal Antiinflammatory Drugs and/or With Active Spinal Lesions. Arthritis Care Res (Hoboken). 2018;70(8):1228-1237. doi:10.1002/acr.23462
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