Reactive Arthritis

Reactive arthritis is a medical condition that is characterized by a combination of symptoms including seronegative arthritis, urethritis, and conjunctivitis. The condition is often associated with sacroiliitis and painful feet, which reflects plantar fasciitis. Reactive arthritis is known to occur after gastrointestinal infections with Shigella or Salmonella, as well as following non-specific urethritis.

Gonococcal arthritis, on the other hand, tends to occur in patients who are systemically unwell and have features of septic arthritis. It is important to note that reactive arthritis is not contagious and cannot be spread from one person to another.

Treatment Options for Rheumatoid Disease: A Comparison of Biological Therapies and DMARDs

Rheumatoid disease can be a debilitating condition that requires careful management. When standard disease-modifying anti-rheumatic drugs (DMARDs) fail to provide relief, biological therapies may be prescribed. Infliximab, adalimumab, and etanercept are some of the contemporary biological therapies available. Infliximab, in particular, is often co-prescribed with methotrexate, although it may cause a reversible lupus-like syndrome and tuberculosis reactivation.

Combining gold, leflunomide, and methotrexate is unlikely to help patients who have already failed DMARD therapy. Azathioprine may be considered in severe cases, but biological therapy is the preferred treatment when intensive DMARD therapy fails. The combination of gold and penicillamine is a viable option for patients who meet the criteria for biological therapy, according to National Institute for Health and Care Excellence (NICE) guidelines. DMARD monotherapy, such as leflunomide, is only recommended when dual therapy is contraindicated.

In summary, the choice of treatment for rheumatoid disease depends on the severity of the condition and the patient’s response to previous therapies. Biological therapies may offer relief for patients who have failed DMARD therapy, but careful monitoring for potential side effects is necessary.

Differentiating Autoantibodies in Connective Tissue Diseases

Connective tissue diseases are a group of autoimmune disorders that affect various parts of the body. Differentiating between these diseases can be challenging, but autoantibodies can provide valuable clues. Here are some common autoantibodies and the connective tissue diseases they are associated with:

1. Anti-centromere antibody: This antibody is most likely to be present in limited systemic sclerosis (CREST).

2. Anti-Scl-70: This antibody is found in diffuse systemic sclerosis.

3. Anti-RNP antibody: This antibody is found in mixed connective tissue disease.

4. Anti-Ro antibody: This antibody is classically positive in Sjögren’s syndrome or systemic lupus erythematosus.

5. Anti-Jo-1 antibody: This antibody is commonly raised in polymyositis.

By identifying the specific autoantibodies present in a patient, healthcare providers can better diagnose and manage connective tissue diseases.

Differential Diagnosis for a Young Man with Purpura and Haematuria

The patient in question presents with a purpuric rash on the back, buttocks, and extensor surfaces of the lower limbs, as well as haematuria. The following is a differential diagnosis of possible conditions that could be causing these symptoms.

Henoch–Schönlein purpura (HSP)
The clinical presentation is entirely typical of HSP, a vasculitic process that results in a purpuric rash and haematuria. It should be noted that platelet numbers are usually normal or raised in HSP, so thrombocytopaenia is not expected.

Haemophilia A
This condition is not likely as it results in joint and muscle bleeding, which is not present in this case. Additionally, haemophilia would not cause haematuria.

Idiopathic thrombocytopaenic purpura (ITP)
While purpura is a symptom of ITP, a reduced platelet count is typically present. Without a discussion of platelet levels, it is difficult to justify a diagnosis of ITP. Additionally, ITP would not result in haematuria.

Leukaemia
If acute leukaemia were causing the symptoms, thrombocytopaenia might be expected. However, the clinical presentation is more compatible with HSP, and thrombocytopaenia alone would not result in haematuria.

Thalassaemia trait
There is no indication in the history to suggest this condition, and it would not result in purpura. Thalassaemia trait is typically asymptomatic.

In conclusion, the patient’s symptoms are most consistent with HSP, a vasculitic process that results in a purpuric rash and haematuria.

Differentiating Knee Conditions: A Case-Based Approach

A patient presents with a red, tender, and inflamed knee. The differential diagnosis includes prepatellar bursitis, osteoarthritis, localised cellulitis, rheumatoid arthritis, and gout.

prepatellar bursitis, also known as housemaid’s knee, carpet layer’s knee, or nun’s knee, is often caused by repetitive knee trauma. Treatment involves non-steroidal anti-inflammatory agents and local corticosteroid injection. Septic bursitis requires appropriate antibiotic cover and drainage.

Osteoarthritis is a diagnosis of exclusion and does not typically cause a red, tender, inflamed knee. Knee aspirate in this case would not show white cells.

Localised cellulitis may result in erythema but is unlikely to cause knee swelling. Knee aspirate in this case would not show white cells.

Rheumatoid arthritis is unlikely to present in men of this age and typically affects small joints of the fingers, thumbs, wrists, feet, and ankles.

Gout can be diagnosed through the presence of negatively birefringent crystals seen on joint microscopy.

In conclusion, a thorough evaluation of the patient’s symptoms and appropriate diagnostic tests are necessary to differentiate between these knee conditions.

After a diarrhoeal illness, the patient may be at risk of developing reactive arthritis, which is a possible diagnosis for both sacroiliitis and plantar fasciitis. However, it is less likely to be related to inflammatory bowel disease (IBD) if there is only one acute episode of diarrhoea.

Sacroiliitis is a condition that affects the sacroiliac joint, which is located at the base of the spine where it connects to the pelvis. It causes inflammation and pain in the lower back, buttocks, and legs. Plantar fasciitis, on the other hand, is a condition that affects the plantar fascia, a thick band of tissue that runs along the bottom of the foot. It causes pain and stiffness in the heel and arch of the foot.

Managing Gout Attacks in Patients on Allopurinol: Options and Considerations

When a patient on allopurinol develops a gout attack, it is important to manage the acute inflammation while continuing the prophylactic treatment. Here are some options and considerations:

– Continue allopurinol and start oral colchicine: Colchicine can be used for acute treatment, but allopurinol should not be stopped.
– Increase allopurinol dose: The dose may need to be increased up to 600 mg for better prophylaxis, but not during an acute attack.
– Stop allopurinol and recommence two weeks after acute inflammation settled: Allopurinol should not be stopped during an attack. It should be continued at the same dose.
– Stop allopurinol and start non-steroidal anti-inflammatory drugs (NSAIDs): NSAIDs can control acute pain, but not appropriate for patients with a history of peptic ulcer.
– Stop allopurinol and recommence at a higher dose after acute inflammation has settled: Allopurinol should not be stopped during an attack. The dose can be reviewed and increased after the attack has settled down.

In summary, managing gout attacks in patients on allopurinol requires a careful balance between acute treatment and prophylaxis. Each option should be considered based on the patient’s individual circumstances and medical history.

Mythbusting Gout: Clarifying Common Misconceptions

Gout is a painful and often misunderstood condition. Here are some common misconceptions about gout, and the truth behind them:

1. Gout may be seen in patients with chronic haemolytic anaemia.
2. Gout may occur in those with elevated urate levels (although levels may be normal during an acute attack) such as those with haemolytic anaemia.
3. Gout only affects the first metacarpophalangeal (MCP) joint.
4. Gout most commonly affects the first metatarsophalangeal joint. However, it is not the only joint affected.
5. Allopurinol is effective in the treatment of acute gout.
6. Acute gout is treated with non-steroidal anti-inflammatory drugs (NSAIDs), colchicine or prednisolone, but not allopurinol. Allopurinol is effective in the prevention of gout because it reduces serum urate levels by blocking urate production (xanthine oxidase inhibition).
7. A diagnosis of gout is made if there are positively birefringent crystals in the joint aspirate.
8. Gout is an inflammatory arthritis that occurs as a result of deposition of negatively birefringent urate crystals in the joint.
9. All cases of acute gout have an elevated serum urate.
10. Although a raised serum urate can be used to support the diagnosis, many will not be raised. Similarly, if a patient has a raised serum urate, they do not automatically have the clinical picture of gout.

In conclusion, it is important to dispel these common myths about gout in order to properly diagnose and treat this painful condition.

Diagnosing Prepatellar Bursitis: Understanding Joint Aspirate Results

Prepatellar bursitis, also known as housemaid’s knee, is a common condition caused by inflammation of the prepatellar bursa. This can result from repetitive microtrauma, such as prolonged kneeling. Patients typically present with localised, mildly tender swelling over the patella, which can be warm but not hot. Aspiration of the aseptic bursa will reveal a clear and/or milky aspirate that has negative Gram staining and normal microscopy.

When examining joint aspirate results, it is important to consider other potential diagnoses. Gram-positive cocci, for example, would be grown in the case of Staphylococcus aureus infection, a common cause of septic bursitis. However, in the absence of fever, erythema, and reduced range of motion, septic arthritis is unlikely. Similarly, needle-shaped crystals with strong negative birefringence on polarised light microscopy are seen in gout, but this condition typically presents with acute pain, redness, and inflammation.

Rhomboid-shaped crystals with weak positive birefringence on polarised light microscopy are seen in pseudogout, which can affect the knee. However, this condition typically affects the entire knee joint and is more common in the elderly.

In summary, a clear or milky joint aspirate with normal microscopy and culture is consistent with prepatellar bursitis. Other potential diagnoses should be considered based on the patient’s history and examination findings.

Medication Combinations for Treating Rheumatoid Arthritis

When treating rheumatoid arthritis, the first-line medication is a DMARD monotherapy with methotrexate. Short-term steroids may also be used in combination with DMARD monotherapy to induce remission. Hydroxychloroquine is another medication that can be used, but patients should be closely monitored for visual changes as retinopathy and corneal deposits are common side effects.

Etanercept is not a first-line treatment for rheumatoid arthritis, and methotrexate should not be given in combination with a TNF-alpha inhibitor like etanercept. Methotrexate plus sulfasalazine is an appropriate medication combination for treating rheumatoid arthritis, but regular eye checks are not required as neither medication affects vision.

If a patient has failed treatment with methotrexate, sulfasalazine plus hydroxychloroquine may be a regimen to consider trialling. However, it is important to note that new-onset rheumatoid arthritis should be treated with a DMARD monotherapy first line, with the addition of another DMARD like methotrexate as the first-line option.