7 Key Symptoms of Paget’s Disease of Bone You Should Know

Introduction

Paget’s disease of bone is a chronic disorder that disrupts the normal cycle of bone renewal, causing bones to become weakened, enlarged, and misshapen. This condition typically affects older adults and can involve one or more bones in the body, most commonly the pelvis, spine, skull, and legs. While many people with Paget’s disease experience no symptoms at all, others may develop significant complications that affect their quality of life.

Understanding the symptoms of this condition is crucial for early detection and proper management. The disease progresses slowly over time, and symptoms may develop gradually, making them easy to overlook initially. In this comprehensive guide, we’ll explore the key symptoms of Paget’s disease of bone, helping you recognize the warning signs and understand when to consult a healthcare professional.

1. Bone Pain

Bone pain is one of the most common and often the first symptom that leads people to seek medical attention. The pain associated with Paget’s disease can vary significantly in intensity and character.

Characteristics of bone pain in Paget’s disease:

• Deep, aching pain that may be constant or intermittent
• Pain that worsens at night or during rest
• Discomfort that increases with weight-bearing activities
• Pain localized to the affected bone areas, commonly the pelvis, lower back, hips, or thighs

The pain occurs because the abnormal bone remodeling process creates bones that are structurally weaker and more susceptible to stress. Additionally, the increased blood flow to affected areas and the expansion of bone tissue can irritate surrounding nerves and tissues, contributing to the discomfort. Some patients describe the pain as a persistent dull ache, while others experience sharper, more intense sensations during movement.

2. Joint Pain and Arthritis

When Paget’s disease affects bones near joints, it can lead to secondary osteoarthritis and significant joint problems. This occurs because the deformed bones alter the normal mechanics of the joint, placing abnormal stress on cartilage and surrounding structures.

Common joint-related symptoms include:

• Stiffness in the hips, knees, or spine
• Reduced range of motion in affected joints
• Pain that worsens with activity and improves with rest
• Swelling around the joints
• Grinding or cracking sensations during movement

The hip and knee joints are particularly vulnerable because they bear significant weight and are frequently located near bones commonly affected by Paget’s disease. The cartilage deterioration can progress more rapidly than typical age-related arthritis, leading to earlier onset of joint dysfunction and the potential need for joint replacement in severe cases.

3. Bone Deformities

As Paget’s disease progresses, the affected bones may become visibly enlarged and deformed. This happens because the abnormal bone remodeling process creates bone that is larger but structurally disorganized and weaker than normal bone.

Common deformities include:

• Bowing of the legs (most commonly the tibia and femur)
• Enlargement of the skull, which may cause hats to fit more tightly
• Curvature of the spine (kyphosis)
• Asymmetry in bone size, with one leg or arm appearing larger or longer than the other
• Protrusion of the forehead or changes in facial structure when skull bones are affected

These deformities typically develop gradually over years and may not be immediately noticeable. In severe cases, the bowing of weight-bearing bones can affect mobility and gait, leading to additional complications such as balance problems and increased risk of falls. The cosmetic changes, particularly when affecting visible areas like the skull or legs, can also impact self-esteem and quality of life.

4. Fractures

Bones affected by Paget’s disease are paradoxically both larger and weaker than normal bones, making them more susceptible to fractures. These fractures can occur with minimal trauma or even during normal daily activities.

Key features of fractures in Paget’s disease:

• Fractures may occur with less force than would typically be required to break healthy bone
• Common fracture sites include the long bones of the legs, particularly the femur and tibia
• Some fractures are incomplete, appearing as fissures or cracks in the bone (called insufficiency fractures)
• Healing may be slower than normal due to the abnormal bone structure
• Sharp, sudden pain often accompanies an acute fracture

The increased fracture risk is due to the disorganized structure of pagetic bone, which lacks the normal architectural strength of healthy bone despite being larger in size. Weight-bearing bones are particularly vulnerable, and even simple activities like stepping off a curb or turning quickly can sometimes result in a fracture in severely affected individuals.

5. Neurological Symptoms

When Paget’s disease affects the skull or spine, the enlarged bones can compress nearby nerves, leading to various neurological complications. These symptoms can be particularly concerning and may significantly impact daily functioning.

Neurological symptoms may include:

• Hearing loss, which is the most common neurological complication, occurring when skull bone growth affects the inner ear structures or auditory nerves
• Headaches, particularly when the skull is involved
• Numbness or tingling in the arms or legs due to nerve compression in the spine
• Weakness in the extremities
• In rare cases, vision problems if bone enlargement affects the optic nerves
• Balance problems and dizziness when the inner ear is affected
• In very rare and severe cases, compression of the spinal cord can occur

Hearing loss in Paget’s disease typically develops gradually and may affect one or both ears. It can result from bone overgrowth in the skull affecting the tiny bones of the middle ear or from compression of the auditory nerve. Early recognition of these neurological symptoms is important, as some complications may benefit from timely medical intervention.

6. Increased Warmth Over Affected Bones

An unusual but characteristic symptom of Paget’s disease is increased warmth of the skin over affected bones. This occurs due to the dramatically increased blood flow to areas of active bone remodeling.

What to know about this symptom:

• The affected area may feel noticeably warmer to the touch compared to surrounding areas
• There may be visible dilated blood vessels over the affected bone
• This increased vascularity is a result of the highly active metabolic process occurring in the diseased bone
• The warmth is typically not accompanied by redness or other signs of infection
• In severe cases, the increased blood flow to bone can rarely affect overall cardiovascular function

While this symptom is less commonly recognized by patients themselves, healthcare providers may specifically check for it during physical examination. The increased metabolic activity and blood flow in affected bones is also why these areas appear more active on certain imaging studies, such as bone scans.

7. Enlarged Head and Related Complications

When Paget’s disease affects the skull, it can lead to progressive enlargement of the head and several associated complications. The skull is one of the most commonly affected sites in this condition.

Skull involvement may cause:

• Gradual increase in head circumference, often first noticed when hats no longer fit properly
• Prominent forehead or changes in facial contours
• Headaches that may range from mild to severe
• Thickening of the skull bones visible on imaging studies
• Dental problems, including loose teeth or malocclusion, when the jaw bones are affected
• In rare cases, increased intracranial pressure

The skull changes occur gradually over many years, so patients may not immediately notice the enlargement. Family members or healthcare providers may be the first to observe these changes. When the base of the skull is involved, there is increased risk of neurological complications due to the proximity of important nerves and blood vessels passing through this area. Jaw involvement can lead to dental complications, making it important for individuals with Paget’s disease to maintain regular dental care.

Main Causes of Paget’s Disease of Bone

The exact cause of Paget’s disease remains unknown, but research has identified several contributing factors:

Genetic Factors:

Heredity plays a significant role in Paget’s disease. Studies show that approximately 15-40% of patients have a family history of the condition. If a close relative has Paget’s disease, your risk of developing it is increased seven to ten times compared to the general population. Researchers have identified several genetic mutations associated with the disease, particularly in the SQSTM1 gene, though having these mutations doesn’t guarantee you’ll develop the condition.

Environmental Triggers:

Some researchers believe that viral infections early in life may trigger Paget’s disease in genetically susceptible individuals. Paramyxoviruses, including measles virus, have been investigated as possible triggers, though this theory remains unproven. Environmental factors may explain why the disease was more common in certain geographic regions and why its prevalence appears to be declining in some areas.

Age-Related Factors:

Paget’s disease is extremely rare in people under 40 and becomes increasingly common with age, particularly after age 50. The risk continues to increase with advancing age. This age-related pattern suggests that the disease may result from accumulated changes over time or age-related alterations in bone cell function.

Geographic and Ethnic Factors:

The disease shows marked variation in prevalence among different populations, being more common in people of European descent, particularly those from the United Kingdom, Western Europe, Australia, and New Zealand. It is less common in Scandinavian countries and rare in Asian, African, and Middle Eastern populations, suggesting both genetic and possible environmental influences.

Frequently Asked Questions

Can Paget’s disease of bone be asymptomatic?

Yes, many people with Paget’s disease have no symptoms at all. In fact, the majority of cases are discovered incidentally during X-rays or blood tests performed for other reasons. It’s estimated that only about 5-20% of people with Paget’s disease experience noticeable symptoms.

Is Paget’s disease of bone the same as Paget’s disease of the breast?

No, these are completely different conditions that happen to share the same name. Paget’s disease of bone affects the skeleton, while Paget’s disease of the breast (also called Paget’s disease of the nipple) is a rare form of breast cancer. They are unrelated conditions with different causes and treatments.

Does Paget’s disease affect the entire skeleton?

No, Paget’s disease typically affects only specific bones, not the entire skeleton. It may involve just one bone (monostotic) or several bones (polyostotic), but it doesn’t spread from bone to bone like cancer. The most commonly affected bones are the pelvis, spine, skull, femur (thighbone), and tibia (shinbone).

Can Paget’s disease lead to cancer?

While extremely rare (occurring in less than 1% of cases), Paget’s disease can occasionally lead to bone cancer, specifically osteosarcoma. This complication is more likely in people with severe, long-standing disease affecting multiple bones. New, severe pain in an area of known Paget’s disease should be evaluated promptly by a healthcare provider.

How is Paget’s disease diagnosed?

Diagnosis typically involves a combination of approaches including blood tests (particularly alkaline phosphatase levels, which are elevated in active disease), X-rays (showing characteristic bone changes), and bone scans (to determine which bones are affected). Sometimes a bone biopsy may be needed to confirm the diagnosis or rule out other conditions.

Can symptoms of Paget’s disease come and go?

Paget’s disease is typically a chronic, progressive condition, but the activity level can vary over time. Bone pain and other symptoms may fluctuate in intensity. Some people experience periods of increased symptoms alternating with relatively stable periods. Regular monitoring with blood tests and imaging can help track disease activity.

At what age do symptoms typically appear?

When symptoms do occur, they typically appear in people over age 50, with the average age of diagnosis being around 60-70 years. The disease is very rare before age 40. However, because many cases are asymptomatic, the disease may be present for years before symptoms develop or the condition is discovered.

Should I see a doctor if I have mild bone pain?

While occasional mild bone or joint pain is common and often not serious, you should consult a healthcare provider if you experience persistent bone pain, any noticeable bone deformity, hearing loss, or if you have a family history of Paget’s disease. Early diagnosis can help prevent complications and guide appropriate monitoring and management.

References:

• Mayo Clinic – Paget’s Disease of Bone
• NHS – Paget’s Disease of Bone
• National Institute of Arthritis and Musculoskeletal and Skin Diseases
• Johns Hopkins Medicine – Paget’s Disease
• NIH Osteoporosis and Related Bone Diseases National Resource Center