AKT

1. A 59 year-old woman with rheumatoid arthritis requires antibiotic prophylaxis for recurrent urinary tract infections. She is currently taking methotrexate on a weekly basis.Which is the SINGLE LEAST appropriate antibiotic to prescribe for this patient? Select ONE option only.

A. Cefalexin
B. Ciprofloxacin
C. Co-amoxiclav
D. Nitrofurantoin
E. Trimethoprim

Answer: E

The BNF states that the excretion of methotrexate is possibly reduced by ciprofloxacin, which increases the risk of methotrexate toxicity. However, this is not as significant as the methotrexate-trimethoprim interaction.There is a risk of cholestatic jaundice with co-amoxiclav, and it would therefore be less suitable for prolonged use in any patient with a history of liver disease.The most serious complication of methotrexate therapy is bone marrow suppression, and hence the need for regular blood monitoring with a full blood count. The concomitant use of an anti-folate drug (e.g. trimethoprim) increases the risk of bone marrow suppression, and should therefore be avoided, especially for prolonged treatment courses.

2. A 30 year-old man presents with an eight month history of low back pain and stiffness which is worse in the mornings. He has a long history of bilateral heel pain.Which is the SINGLE MOST likely diagnosis in this patient? Select ONE option only. [Show Discussion]

A. Ankylosing spondylitis
B. Osteoarthritis
C. Psoriatic arthritis
D. Reactive arthritis
E. Rheumatoid arthritis

Answer: A

The history of stiffness suggests an inflammatory condition in this patient. Ankylosing spondylitis is more common in young men. There may be a positive family history, and there is a strong association with HLA B27. Extra-articular manifestations include Anterior uveitis, Apical lung fibrosis, AV heart block, Aortic regurgitation and aortitis, Amyloidosis, Achilles tendonitis and plantar fasciitis.This would be the main differential diagnosis here, as psoriatic arthritis can present with a spondyloarthropathy or sacroiliitis.It would be unusual for symptoms to continue for eight months with a reactive arthritis, and there would be usually be a preceding history of (typically) a gastrointestinal infection.

3. A 15 year-old boy presents with a two month history of fever and a painful, red swelling just above his left knee. There is no history of trauma.Which is the SINGLE MOST likely diagnosis in this patient? Select ONE option only.

A. Ewing’s sarcoma
B. Juvenile idiopathic arthritis
C. Osgood-Schlatter’s disease
D. Osteomyelitis
E. Reactive arthritis

Answer: A

This is a rare but important diagnosis not to miss. It accounts for 2% of all childhood cancers. It is more common in males and typically presents in children and young adults aged 5-20 years. It may mimic an infective process, but red flag symptoms of fever, persistent pain (including nocturnal and rest pain) and persistent localised swelling should prompt an urgent referral to exclude a malignant lesion.Juvenile idiopathic arthritis refers to the onset of arthritis in a patient under the age of 16, which lasts for more than three months. If there are associated systemic features (e.g. fever, rash, lymphadenopathy), then it is referred to as Still’s disease.Osgood-Schlatter’s disease is an overuse condition which presents with pain (often bilateral) and tenderness over the tibial tuberosity, usually around the time of the pubertal growth spurt. Symptoms improve with rest. There should be no red flag symptoms present.Osteomyelitis would be unlikely in the absence of trauma, although can occur (e.g. from haematogenous spread).

4. A 38 year-old man presents having recently joined your practice. He is currently taking bendroflumethiazide for hypertension. He complains of recurrent episodic swelling and pain in his right ankle over the last three years. The practice nurse elicited the following clinical information at a new patient check yesterday:BMI 34.6BP 144/90Smoking status Ex-smokerAlcohol intake 40 units per weekUrinalysis Protein 1+Which is the SINGLE MOST likely diagnosis in this patient? Select ONE option only. [Show Discussion]

A. Gout
B. Osteoarthritis
C. Psoriatic arthritis
D. Reiter’s syndrome
E. Rheumatoid arthritis

Answer: A

The combination of alcohol excess and use of bendroflumethiazide make gout the most likely diagnosis here. Most cases of gout are idiopathic, but identifiable causes include: increased purine levels (e.g. diet and alcohol), decreased urate excretion (e.g. renal failure) and drugs (e.g. thiazide and loop diuretics). Common sites of involvement include the metatarsophalangeal joint (MTPJ) of the big toe, the ankle joint and the finger joints. Factors precipitating acute attacks of gout include dehydration, alcohol, trauma and infection.Osteoarthritis would be unlikely in a 38 year-old patient.The asymmetrical oligoarthropathy subtype of psoriatic arthritis would be the main differential diagnosis here. However, this is less common than gout, and therefore less likely.Reiter’s syndrome is a triad of urethritis, conjunctivitis and seronegative arthritis. There is an association with HLA B27 and it usually occurs following a genital or gastrointestinal infection (e.g. chlamydia, gonorrhoea, shigella or campylobacter).Rheumatoid arthritis typically presents as a symmetrical polyarthropathy with morning stiffness affecting the small joints of the hands and feet. It affects women more commonly than men.

5. A 22 year-old woman presents to an out of hours GP after slipping on a wet pavement. She complains of pain in her right ankle.According to the Ottawa ankle rules, which SINGLE clinical finding indicates the need for an ankle x-ray? Select ONE option only. [Show Discussion]

A. Bony tenderness over the anterior tip of the medial malleolus
B. Bony tenderness over the posterior tip of the lateral malleolus
C. Inability to dorsiflex the ankle
D. Inability to plantarflex the ankle
E. Swelling over the lateral malleolus

Answer: B

The Ottawa rules clearly state the indications for a plain film x-ray of the ankle, foot and knee.An ankle x-ray is required only if there is pain in the malleolar area, associated with any of the following:
• Pain on palpation over the posterior tip/edge of the lateral malleolus
• Pain on palpation over the posterior tip/edge of the medial malleolus
• Inability to weight bear
The Ottawa rules can be found at www.gp-training.net

6. A 56 year-old woman presents complaining of thoracic back pain. A plain film x-ray of her thoracic spine confirms a vertebral wedge fracture at T10. Her GP requests a DEXA scan to assess bone mineral density.Which SINGLE result would confirm a diagnosis of osteoporosis in this patient? Select ONE option only. [Show Discussion]

A. T score of -2.6
B. T score of -2.1
C. T score of +1.7
D. Z score of -1.3
E. Z score of +2.2

Answer: A

Bone mineral density (BMD) is usually expressed as the number of standard deviations (SD) from the young adult mean. This is known as the T score. Normal bone density is within 1 SD of the young adult mean (i.e. T score > -1). Osteopenia is defined by a T score between -1 and -2.5. Osteoporosis is defined as a T score < -2.5. BMD can also be expressed as the number of standard deviations from the age-related mean. This is the Z score, which enables a patient's risk to be compared to other patients of the same age

7. A 67 year-old man complains of aches and pains in his lower back and pelvis. The pain is constant and worse at night. Investigations including blood tests and a lumbar spine x-ray are requested. The lumbar spine x-ray reveals characteristic changes of Paget’s disease.Which is the SINGLE MOST likely bone profile result to be expected in Paget’s disease? Select ONE option only. [Show Discussion]

A. Low serum calcium, normal alkaline phosphatase
B. Normal serum calcium, normal alkaline phosphatase
C. Normal serum calcium, raised alkaline phosphatase
D. Raised serum calcium, normal alkaline phosphatase
E. Raised serum calcium, raised alkaline phosphatase

Answer: C

In Paget’s disease, the classical biochemical finding is an elevated alkaline phosphatase with a normal serum calcium. This reflects an increase in osteoclastic activity and bone turnover. Mild hypercalcaemia can occasionally be found if the patient has been immobile for a prolonged period.