Differential Diagnosis for Back Pain after Lifting Heavy Object with Fever and Chills

Single Most Likely Diagnosis

• Muscle Strain with Secondary Infection: This is the most likely diagnosis given the initial onset of back pain after lifting a heavy object, which suggests a mechanical injury. The subsequent development of fever and chills could indicate a secondary infection of the muscle strain, although this is less common.

Other Likely Diagnoses

• Herniated Disk with Infection: Lifting a heavy object can cause a herniated disk, and if the disk material becomes infected, it could lead to fever and chills.
• Pyelonephritis: Kidney infection can cause back pain (often flank pain), fever, and chills. The initial back pain after lifting could be coincidental.
• Osteomyelitis: An infection of the bone, which could be related to the initial trauma from lifting, although this is less common.

Do Not Miss Diagnoses

• Spinal Epidural Abscess: A serious and potentially life-threatening condition that requires immediate medical attention. It can cause back pain, fever, and chills, and any delay in diagnosis can lead to severe neurological deficits or death.
• Spinal Cord Injury with Infection: If the lifting caused a spinal cord injury, and it became infected, this would be a medical emergency.
• Sepsis from any Source: Sepsis can cause back pain, fever, and chills among many other symptoms. Identifying and treating the source of sepsis is crucial.

Rare Diagnoses

• Discitis: An infection of the intervertebral disc space, which is rare but can occur after trauma.
• Vertebral Osteomyelitis: Similar to discitis, this is an infection of the vertebral body and is rare.
• Psoas Abscess: An abscess in the psoas muscle, which can cause back pain and fever. It's more common in certain populations (e.g., those with spinal infections) but is rare in the general population.

Each of these diagnoses has a different level of urgency and required treatment, ranging from rest and antibiotics for muscle strain with infection to immediate surgical intervention for conditions like spinal epidural abscess. A thorough medical evaluation, including history, physical examination, and appropriate diagnostic tests (e.g., imaging studies, blood cultures), is necessary to determine the correct diagnosis and guide treatment.