Differential Diagnosis for Lower Back Pain
The patient's presentation of diffuse lower back pain following heavy lifting, with alleviation by OTC Salonpas patches and ibuprofen, and aggravation by prolonged standing, sitting, or bending, suggests a musculoskeletal origin. The absence of red flags such as fever, chills, body aches, unintentional weight loss, saddle anesthesia, urinary retention, leg weakness, sciatica, or gross hematuria helps to narrow down the differential diagnoses.
Single Most Likely Diagnosis
- Musculoskeletal Strain: The patient's history of recent heavy lifting followed by the onset of lower back pain, which is exacerbated by movement and partially relieved by rest and over-the-counter pain medications, strongly suggests a musculoskeletal strain. The physical examination findings of mild tenderness to the lumbosacral region and pain with flexion, extension, rotation, and lateral bending further support this diagnosis.
Other Likely Diagnoses
- Lumbar Disc Herniation: Although the patient denies sciatica or pain radiating to the lower extremities, a small, non-impinging disc herniation could still cause lower back pain without radiculopathy. The absence of significant neurological deficits or severe pain does not rule out this possibility entirely.
- Degenerative Disc Disease: Given the patient's age and the presence of moderate, tolerable pain that is exacerbated by certain movements, degenerative disc disease could be a contributing factor. However, the acute onset following physical activity makes this less likely as the primary diagnosis.
- Spondylosis or Spondylolisthesis: These conditions could cause lower back pain, especially with activities that increase lumbar lordosis or stress the pars interarticularis. However, the lack of specific findings on physical examination, such as step-off or significant pain with extension, makes these less likely.
Do Not Miss Diagnoses
- Cauda Equina Syndrome: Although the patient denies urinary retention, incontinence, or significant leg weakness, cauda equina syndrome is a medical emergency that must be considered, even if the likelihood is low. Any new onset of these symptoms would necessitate immediate further evaluation.
- Spinal Infection (e.g., Discitis or Osteomyelitis): The absence of fever, chills, or significant systemic symptoms makes this less likely, but it remains a critical diagnosis not to miss due to its potential for serious complications.
- Malignancy (Metastatic or Primary): While the patient's history does not strongly suggest malignancy (e.g., no unintentional weight loss, night pain), it is always a consideration in the differential diagnosis of back pain, especially in older adults.
Rare Diagnoses
- Ankylosing Spondylitis: This chronic inflammatory disease could cause lower back pain and stiffness, but it typically presents with a more gradual onset and is associated with morning stiffness and improvement with activity. The patient's acute presentation and lack of systemic symptoms make this less likely.
- Osteoporotic Compression Fracture: Although the patient's mother has osteoporosis, the patient himself does not have a known history of osteoporosis, and his age and gender make this diagnosis less likely without significant trauma or other risk factors.