Signs and Symptoms - Paget's disease is often asymptomatic in mild or early cases - The most common symptom is bone pain - Symptoms may be confused with arthritis or other disorders - Increasing deformity of bones may be noticed - Skull involvement may cause frontal bossing, increased hat size, and headaches

Associated Conditions - Paget's disease can lead to osteoarthritis due to changes in bone shape - Severe Paget's disease may result in heart failure - Kidney stones are more common in patients with Paget's disease - Nervous system problems can occur due to increased pressure on the brain or spinal cord - Facial bone involvement may cause loose teeth and chewing difficulties

Causes - Paget's disease may be caused by a slow virus infection - Viral infections associated with Paget's disease include respiratory syncytial virus, canine distemper virus, and measles virus - Genetic factors play a role in the development of Paget's disease - Mutations in genes SQSTM1 and RANK are associated with Paget's disease - About 40-50% of people with inherited Paget's disease have a mutation in the SQSTM1 gene

Pathogenesis and Treatment - Paget's disease progresses through four stages: osteoclastic activity, mixed osteoclastic-osteoblastic activity, osteoblastic activity, and malignant degeneration - Initially, there is increased bone resorption caused by osteoclasts - This is followed by compensatory bone formation by osteoblasts - The bone formation is disorganised, resulting in a mosaic pattern - The bone becomes hypervascular and may eventually become dense or 'burned-out' - There is no cure for Paget's disease, but medications can help control symptoms - Bisphosphonates and calcitonin are commonly used medications for Paget's disease - Treatment is more successful when started early before complications arise

Diagnosis, Medication, Surgery, and Specialists - Elevated alkaline phosphatase in the blood is the first clinical manifestation - Pagetic bone has a characteristic appearance on X-rays - Urine markers of bone turnover, such as pyridinoline, can be used - Elevated levels of serum and urinary hydroxyproline are found - Bone scans can determine the extent and activity of the condition - Medications are recommended for those with bone pain, elevated alkaline phosphatase levels, or risk of bone fracture - Bisphosphonates like risedronic acid, alendronic acid, and pamidronic acid are commonly prescribed - Neridronate and etidronate disodium are also used, with specific dosing regimens - Zoledronic acid is given as an intravenous infusion and is effective for two years - Surgery may be recommended for fractures, severe degenerative arthritis, and bone deformity - Fractures may heal in a better position with surgery - Joint replacement of hips and knees may be considered for severe arthritis - Osteotomy, cutting and realignment of pagetic bone, can help with painful weight-bearing joints - Endocrinologists, rheumatologists, orthopedic surgeons, neurosurgeons, neurologists, oral and maxillofacial surgeons, and otolaryngologists are knowledgeable about treating Paget's disease - Various specialists may be involved in the ongoing management and treatment of the disease.