What are the possible etiologies of right lower rib pain?

Causes of Right Lower Rib Pain

Right lower rib pain has multiple potential etiologies including musculoskeletal causes (rib fractures, costochondritis, slipping rib syndrome), infectious processes (osteomyelitis, tuberculosis), neoplastic lesions (metastases, primary bone tumors), and nerve-related conditions (intercostal neuralgia, intercostal neuromas). 1

Musculoskeletal Causes

Rib Fractures

• Most common cause in the setting of trauma or severe coughing episodes 1
• Can occur from high-energy mechanisms or low-energy impacts (particularly in elderly patients with osteoporosis)
• Lower rib fractures (ribs 7-12) may be associated with intra-abdominal organ injury in 67% of patients with multiple injuries 2
• Right-sided lower rib fractures specifically warrant consideration of hepatic injury in polytrauma patients, though absence of fractures does not rule out liver injury 2

Slipping Rib Syndrome (SRS)

• Hypermobility of ribs 8-10 causing the cartilaginous rib tip to slip under the adjacent superior rib 3
• Results in intercostal nerve impingement with intermittent, often debilitating pain
• Patients typically report months to years of symptoms before diagnosis 3
• Pain is sudden onset with jerking motion, can be localized or radiating
• Hooking maneuver (pulling the rib margin anteriorly) reproduces pain and is diagnostic 3, 4
• Dynamic ultrasound can confirm diagnosis in difficult cases 3

Costochondritis

• Inflammation of costochondral junctions
• Detected in 4.9% of patients with atypical chest pain on bone scintigraphy 1
• Typically presents with reproducible tenderness on palpation

12th Rib Syndrome

• Irritation or entrapment of the 12th intercostal nerve due to structural abnormalities or trauma to the 12th rib 5
• Causes hypochondrial and flank pain
• Often overlooked, leading to prolonged diagnostic delays 5

Infectious Causes

Osteomyelitis

• Bacterial infection of rib bone 1
• Presents with localized pain, swelling, and constitutional symptoms
• May require advanced imaging (MRI) for diagnosis

Tuberculosis of the Rib

• Accounts for <1% of musculoskeletal TB 6
• Presents with dull-aching pain, swelling, and constitutional symptoms
• Routine chest X-ray may be normal; MRI reveals lytic rib lesions 6
• Diagnosis confirmed by gene-expert testing of aspirated material
• Responds well to anti-tubercular therapy 6

Neoplastic Causes

Metastatic Disease

• Detected in 1.8% of patients with atypical chest pain on bone scintigraphy 1
• Consider in patients with known malignancy or constitutional symptoms
• May present with progressive, unremitting pain

Primary Bone Tumors

• Less common but important differential
• Require tissue diagnosis for definitive management

Neurologic Causes

Intercostal Neuralgia

• Nerve irritation without structural abnormality
• Can result from viral infections (post-herpetic neuralgia), trauma, or idiopathic causes

Intercostal Neuromas

• Should be considered in the setting of blunt intercostal trauma 7
• Can cause severe chronic pain for years before diagnosis
• Musculoskeletal ultrasound aids in diagnosis 7
• Definitive treatment is surgical resection

Other Causes

Mediastinal Fat Necrosis

• Can be diagnosed on chest CT 1
• Presents with acute chest wall pain

Arthritis

• Costovertebral or costochondral joint arthritis 1
• Typically chronic, progressive pain

Diagnostic Approach

Initial evaluation should focus on:

• Mechanism of injury (trauma, severe coughing, high-intensity athletics)
• Pain characteristics (sudden vs. gradual onset, reproducible with movement, clicking sensation)
• Associated symptoms (fever, weight loss, night sweats suggesting infection or malignancy)
• Physical examination findings (point tenderness, hooking maneuver positivity, visible swelling)

Imaging strategy per ACR guidelines:

• Chest radiography is the appropriate initial test for most patients with nontraumatic chest wall pain 1
• Add dedicated rib views if focal pain is detected on physical examination 1
• CT chest reserved for patients with clinical risk factors (suspected infection, malignancy, or need to evaluate pulmonary disease) 1
• MRI useful for characterizing extent of chest wall or osseous involvement on case-by-case basis 1

Critical Pitfalls

• Slipping rib syndrome is frequently missed due to lack of awareness; always perform hooking maneuver in lower rib pain 3, 4
• Normal chest X-ray does not exclude significant pathology (particularly rib cartilage abnormalities, costochondral junction issues, or early TB) 1, 6
• Lower rib fractures in polytrauma require high suspicion for intra-abdominal injury even with normal physical examination 2
• Intercostal neuromas should be considered in any patient with chronic rib pain following blunt trauma 7
• 12th rib syndrome causes prolonged diagnostic odysseys; maintain high index of suspicion for hypochondrial pain 5