Anti-TNF-α therapy is effective for patients with arthritis but it can oftentimes lead to the reactivation of latent TB. Hence it should be used with great caution in patients with a past history of TB or current infection.

Osteoblastic (or sclerotic) bony metastases, characterized by deposition of new bone, present in prostate cancer, carcinoid, small cell lung cancer, Hodgkin lymphoma or medulloblastoma. The other cancers listed in the options are osteolytic.

Cubital Tunnel Syndrome is a condition that involves pressure or stretching of the ulnar nerve (also known as the “funny bone” nerve), which can cause numbness or tingling in the 4th and 5th digit, pain in the forearm, and/or weakness in the hand. Epicondylitis of the elbow is a condition associated with repetitive forearm and elbow activities. Both lateral epicondylitis (commonly known as tennis elbow) and medial epicondylitis (commonly known as golfer’s elbow) are characterized by elbow pain during or following elbow flexion and extension. Radial tunnel syndrome is a set of symptoms that include fatigue or a dull, aching pain at the top of the forearm with use. Although less common, symptoms can also occur at the back of the hand or wrist.

Cervical radiculopathy is usually due to compression or injury to a nerve root by a herniated disc or degenerative changes. Levels C5 to T1 are the most commonly affected. It is usually, but not always, accompanied by cervical radicular pain, a sharp and shooting pain that travels from the neck and down the upper limb and may be severe. This needs to be differentiated from pain referred from the musculoskeletal (somatic) structures in the neck, which may be aching rather than sharp, and is more severe in the neck than in the upper limb. The neurological signs of cervical radiculopathy depend on the site of the lesion. The patient may have motor dysfunction, sensory deficits or alteration in tendon reflexes. While pain is a common presenting symptom, not all radiculopathies are painful (i.e. only motor deficits may be obvious). CT scanning cannot accurately demonstrate the commonest cause for cervical radiculopathy (disc herniation) without myelography, which requires hospital admission, lumbar puncture and the use of contrast. In patients with cervical radiculopathy, MRI is the imaging technique of choice for the detection of root compression by disc herniation and osteophytes. MRI allows the nerve roots to be directly visualised. Nerve conduction studies are also useful in determining the nerve roots that are involved.

Most patients with psoriatic arthritis present with monoarthritis or asymmetric oligoarthritis. The most common form of the disease is the one involving a few joints of the peripheral skeleton with a distinct asymmetry of symptoms. Involvement of the smaller joints of the hands and feet, especially distal interphalangeal joints, seems to be a characteristic feature. Arthritis mutilans is a rare and severe complication of psoriatic arthritis.

Pseudogout is a paroxysmal joint inflammation due to calcium pyrophosphate crystal deposition (calcium pyrophosphate dihydrate). Arthrocentesis should be performed, especially in acute cases.
Polarized light microscopy: detection of rhomboid-shaped, positively birefringent CPPD crystals.
Synovial fluid findings: 10,000-50,000 WBCs/μL with > 90% neutrophils.
X-ray findings: cartilage calcification of the affected joint (chondrocalcinosis).
Fibrocartilage (meniscus, annulus fibrosus of intervertebral disc) and hyaline cartilage (joint cartilage) may be affected.

Blood pressure should be routinely measured as leflunomide may cause hypertension and thus an increase in BP. It doesn’t cause changes in blood sugar levels, peak expiratory flow rate or haematuria.

People with polyarteritis nodosa often exhibit anaemia of chronic disease. Leucocytosis and eosinophilia may also be present. ANCA is only rarely positive. As polyarteritis nodosa affects the kidneys as well, the creatinine is elevated in most cases.

Old age, persistent backache, weight loss, and osteosclerotic lesions make prostatic adenocarcinoma the most likely diagnosis. The sequelae include severe pain, pathological fractures, hypercalcemia and cord compression. Prostatic adenocarcinoma is detected by elevated levels of prostate specific antigen. Positive serology for borrelia burgdorferi would hint at Lyme disease which does not cause osteosclerotic bone lesions, neither would Neisseria gonorrhoeae have such a presentation.

Polymyositis is an inflammatory disorder causing symmetrical, proximal muscle weakness. It is thought to be a T-cell mediated cytotoxic process directed against muscle fibres. It may be idiopathic or associated with connective tissue disorders. It may also be associated with malignancy for example small cell lung carcinoma.
Dermatomyositis is a variant of the disease where skin manifestations are prominent, for example a purple (heliotrope) rash on the cheeks and eyelids.
It typically affects middle-aged, female: male 3:1. Features include proximal muscle weakness +/- tenderness, Raynaud’s phenomenon, respiratory muscle weakness, interstitial lung disease: e.g. fibrosing alveolitis or organising pneumonia, dysphagia, dysphonia. Investigations: elevated creatine kinase, other muscle enzymes (lactate dehydrogenase (LD), aldolase, AST and ALT) are also elevated in 85-95% of patients, EMG, muscle biopsy. Anti-Jo-1 antibodies are seen in pattern of disease associated with lung involvement, Raynaud’s and fever. Interstitial lung disease plays a major role in morbidity and mortality in patients with polymyositis and is considered a major risk factor for premature death in patients with myositis.