Answers for May 2016 Clinical Image

2016_05

76yo M w/ no known DM and HTN presents for refill of medication. On your physical exam you notice nodules like the ones pictured above.

1.What is it? Gouty tohpus

2.Describe the pathophysiology of these nodular formation
Gout is a metabolic disorder leading to high levels of uric acid in the blood. Uric acid eventually accumulates in tissue, precipitates, and forms crystals. Lower temperature facilitates uric acid precipitation leading to crystal formation in the body periphery (MTJ, fingers, etc).

The crystals have a distinctive appearance under microscopy employing a polarizing filter. A joint aspirate may reveal negatively birefringent crystals like those pictured below

Fluorescent_uric_acid

3.What imaging or lab work would you do?

  • Labs: No lab is required if you have a strong clinical suspicion of gout/tophi (ie- if patients have a history of gout and are presenting with typical presentations). Otherwise a joint aspiration may be necessary to establish the diagnosis and to distinguish it from more serious illness such as a septic joint.
  • Imaging:  Xrays in the ED are generally not helpful in diagnosing gout. In this case where the patient is presenting with large tophi formation, Xray may be helpful in determining if there is bony damage and the extent of damage. However, this is not emergent and patient can have this done outpatient.

4.What treatment would you recommend?

Tophi: tophi formation will damage the tissue around it including muscles, tendons, and ligaments. They may require surgical debridement to prevent further damage. Gout disease needs to be controlled to lessen the number of attacks and to prevent further tophi formation.

Gout: 

  • Acute attacks:
    • NSAIDs are the mainstay of treatment for painful gout attacks.
    • Colchicine and steriod therapy can also be used if the patient has a contraindication for NSAID or is refractory to NSAID treatment. Colchicine’s mechanism of action is not completely understood but it is thought to decrease uric acid production and has anti inflammatory properties.
  • Chronic treatment:
    • Allopurinol and Febuxostat: Xanthine oxidase inhibitors that block the formation of uric acid
    • Uricase: catalyzes oxidation of uric acid. Used in patients with hyperuricemia due to chemotherapy and treatment refractory gout. Could be used in our patient for a short time course to lower uric acid before starting on allopurinol or febuxostat.
  • Ultimately, these are medications to be aware of for emergecy medicine physician but should be left to a rheumatologist or primary care physician to prescribe.

5. Dispo? home w/ rheumatology and surgical follow up

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