Chronic Recurrent Multifocal Osteomyelitis (CRMO)

What is Chronic Recurrent Multifocal Osteomyelitis (CRMO)?

Chronic Recurrent Multifocal Osteomyelitis (CRMO), also known as Chronic Non-infectious Osteomyelitis (CNO), is a rare condition that involves inflammation of one or more bones that can be chronic (long-term).

It is a fluctuating condition, which means that symptoms can come and go over time. Inflammation is a normal process and is the way our immune system protects our bodies from infections and germs. The symptoms of inflammation are pain, redness, and swelling. In CRMO, however, there is no infection. Instead, the immune system wrongly attacks normal bone causing inflammation.

What are the main symptoms of CRMO?

The main symptoms are:

• bone or joint pain
• local bone swelling and tenderness
• limping or loss of function
• skin lesions (such as psoriasis or acne)

What causes CRMO?

The cause of CRMO is unknown, however genetic and environmental factors may play a role.

How is CRMO diagnosed?

CRMO is a ‘diagnosis of exclusion’, which means that other conditions must be ruled out before the diagnosis can be made. Your child may need many tests in order to make the diagnosis, including:

• blood tests
• X-rays
• bone scans
• MRI scans
• sometimes bone biopsy may be required

We treat CRMO so that we can:

• Reduce inflammation
• Prevent bone damage and bone deformities
• Help avoid growth problems
• Reduce symptoms of pain
• Help your child to return to their usual activities

How is CRMO treated?

CRMO is treated by a paediatric rheumatologist.

The condition is not the same for every child, and not every child responds to every treatment or medication. The type of bone involvement and the duration and the severity of symptoms can vary.

Your rheumatology doctor may need to try several different medications before finding the one that works best for your child. Sometimes your child may need a combination of medications to treat the condition. Your rheumatology doctor will work with you to find the best treatment for your child. Sometimes, the condition can be managed with nonsteroidal anti-inflammatory medicines (NSAIDs). However, if NSAIDs are not effective, or if your child does not tolerate NSAIDs well, other treatments are available.

Your doctor will have a discussion with you prior to starting any new treatment.

What happens after my child begins treatment?

Your child’s rheumatology doctor will make sure your child gets the right treatment. CRMO is a chronic condition where symptoms can come and go for years. Children might have inflammation in other bones without any symptoms, and for this reason your doctor will want to see your child even if they are feeling well. Once your child is on effective treatment, they should begin to feel better.

The rheumatology doctor will carefully monitor your child. It is important to keep all of your appointments because your doctor will need to continue to monitor for bone inflammation and any problems with the medications.