Do adults get CRMO? Understanding Adult-Onset Chronic Recurrent Multifocal Osteomyelitis

While chronic recurrent multifocal osteomyelitis (CRMO) is predominantly a childhood disease, adults can absolutely get CRMO, though it is considered very rare, accounting for only a small fraction of all reported cases. This fact underscores a significant challenge in its diagnosis, as many healthcare providers may not consider it in adult patients.

Quick Summary

Adult-onset Chronic Recurrent Multifocal Osteomyelitis (CRMO) is a rare inflammatory bone disease that, while typically found in children, can manifest in adulthood. It is often misdiagnosed due to its rarity and symptoms mimicking other more common conditions, requiring a thorough diagnostic process.

Key Points

• CRMO is Rare but Possible in Adults: Although it primarily affects children, CRMO can present in adults, making diagnosis more challenging due to its low prevalence.

• Adult Symptoms Can Vary: Unlike the classic presentation in children, adult-onset CRMO often affects different bones, like the spine and sternum, and may be accompanied by other inflammatory conditions.

• Diagnosis is Complex and Often Delayed: Because adult CRMO is so rare, it is frequently misdiagnosed as an infection or malignancy, necessitating a thorough 'diagnosis of exclusion' through imaging and biopsy.

• SAPHO Syndrome is Related: Some researchers believe adult-onset CRMO exists on a spectrum with SAPHO syndrome, which involves bone inflammation alongside skin and joint issues.

• Treatment Focuses on Managing Inflammation: While NSAIDs are the first-line treatment, severe or persistent cases often require stronger medications like corticosteroids or biologics to control the body's inflammatory response.

• Early Recognition Prevents Complications: Timely and accurate diagnosis is crucial for preventing potential long-term complications, such as chronic pain or bone deformities.

What is Chronic Recurrent Multifocal Osteomyelitis?

Chronic recurrent multifocal osteomyelitis, or CRMO, is an autoinflammatory disorder of the bones characterized by recurrent episodes of pain, tenderness, and swelling without a known infection. The body's immune system triggers inflammation in one or more bones, with genetics and immune dysregulation being suspected causes.

CRMO in the adult population

CRMO is primarily a disease of childhood and adolescence, but it can occur in adults, albeit rarely. Case studies and registries indicate adult-onset CRMO exists, with the average age of onset in adults around 33. Adult-onset CRMO may be considered part of the SAPHO syndrome spectrum, which shares similar inflammatory features.

Symptoms and presentation in adults

Adult-onset CRMO symptoms can differ from those in children and may involve different bone locations, complicating diagnosis.

Common signs of adult CRMO:

• Chronic bone pain: Often in the back, pelvis, and sternum, contrasting with the long bone involvement typical in children.
• Joint pain: Arthritis may occur alongside bone lesions.
• Elevated inflammatory markers: Blood tests may show elevated CRP and ESR, but usually normal white blood cell counts.
• Skin issues: Some adults may have associated conditions like palmoplantar pustulosis or psoriasis.
• Recurrence: The disease course often involves cycles of symptom flare-ups and periods of remission.

Navigating the diagnostic hurdles

Diagnosing CRMO in adults is challenging and often involves a process of exclusion to rule out more common and serious conditions.

The diagnostic process typically involves:

1. Medical history and physical exam: Symptom review and physical assessment.
2. Blood work: To check inflammatory markers and exclude other diseases.
3. Imaging studies: MRI is highly sensitive for identifying bone lesions, and whole-body MRI can detect multiple sites of inflammation. X-rays and bone scans may also be used.
4. Bone biopsy: Often needed to confirm the diagnosis and rule out malignancy or infectious osteomyelitis, revealing sterile inflammatory cells.

Treatment options for adult CRMO

Treatment aims to control inflammation and manage pain, focusing on preventing long-term complications. Approaches are individualized due to the disease's unpredictable nature.

Treatment strategies include:

• NSAIDs: Frequently the initial treatment for pain and inflammation.
• Corticosteroids: Used for severe flares or when NSAIDs are ineffective.
• Bisphosphonates: Can help reduce bone inflammation, particularly in the spine.
• Biologics and JAK Inhibitors: Newer therapies targeting specific inflammatory pathways may be used in difficult cases, such as tocilizumab or tofacitinib.
• Genetic Factors: For more information on the evolving understanding of this autoinflammatory condition, including potential genetic links, you can read research available on authoritative sites like the National Institutes of Health. Read more here.

CRMO vs. Bacterial Osteomyelitis in Adults

Differentiating CRMO from bacterial osteomyelitis or malignancies like intraosseous lymphoma in adults is crucial. The table below highlights key differences.

Feature	CRMO in Adults	Bacterial Osteomyelitis
Cause	Autoinflammatory, non-infectious	Infection (e.g., bacterial)
Pathology	Sterile inflammatory infiltrates	Purulent material, bacteria
Symptom Onset	Insidious, chronic, relapsing	Acute, often with high fever
Bone Involvement	Often multifocal; common in vertebrae, clavicle	Typically unifocal; any bone
Associated Signs	Can have skin/bowel issues	Localized redness, warmth, pus
Lab Findings	Mildly elevated CRP/ESR, normal WBC	Often significantly elevated markers, high WBC

Living with adult-onset CRMO

Managing adult-onset CRMO requires a proactive approach and often a team of specialists, including a rheumatologist. Adhering to the treatment plan is vital to minimize flares and prevent complications like bone deformity or chronic pain. Support groups and organizations like the CRMO Foundation offer valuable resources.

Conclusion

While CRMO is most frequently diagnosed in pediatric populations, awareness that adults can also be affected is important for both patients and clinicians. The rarity of the condition in adults and overlapping symptoms with other serious diseases make accurate diagnosis challenging. Including CRMO in differential diagnoses and utilizing advanced imaging and biopsy when necessary can lead to better outcomes for adult patients with unexplained, recurrent bone pain. Timely and accurate diagnosis is essential for effective treatment and improved quality of life.

Frequently Asked Questions

What is the likelihood of an adult getting CRMO?

The likelihood is very low. CRMO is considered a very rare disease overall, and adult-onset cases represent a small fraction of the total patient population, with estimates suggesting only about 10% of cases occur in those over 20 years old.

Is adult CRMO different from SAPHO syndrome?

This is a topic of debate in the medical community. Some experts believe adult-onset CRMO is part of the SAPHO syndrome spectrum, especially when associated with skin manifestations like pustulosis. Others see them as related but distinct conditions.

Why is CRMO so difficult to diagnose in adults?

Diagnosis is difficult because CRMO symptoms can mimic more common conditions, including infectious osteomyelitis, lymphoma, and other bone malignancies. A definitive diagnosis is typically only reached after excluding these possibilities through extensive testing, including biopsies.

What kind of doctors treat adult CRMO?

Adults with CRMO are typically treated by a rheumatologist, who specializes in inflammatory and autoimmune diseases affecting joints, bones, and muscles. Other specialists, such as orthopedic surgeons or infectious disease doctors, may be involved during the diagnostic process to rule out other conditions.

Can adult-onset CRMO be cured?

While the disease course varies greatly and some individuals experience long periods of remission, CRMO is generally considered a chronic, relapsing condition rather than a curable one. Treatment focuses on managing symptoms and controlling inflammation to maintain remission.

Are there any genetic factors involved in adult CRMO?

Research suggests there may be a genetic component to CRMO, with some cases linked to genetic mutations associated with other autoinflammatory illnesses. However, most cases are sporadic and the exact genetic links are still under investigation.

How do imaging tests help with an adult CRMO diagnosis?

Imaging, particularly MRI, is crucial for showing the extent of bone inflammation and identifying all affected areas, including asymptomatic ones. Whole-body MRI can be especially useful for detecting multifocal lesions, which is a key characteristic of CRMO.