Tophi as the initial manifestation of gout in a normouricemic hemodialysis patient: An unusual case of a common disorder

Hamzi Mohamed Amine

doi:10.4103/1319-2442.198278

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LETTER TO THE EDITOR

Year : 2017 | Volume : 28 | Issue : 1 | Page : 194-195

Tophi as the initial manifestation of gout in a normouricemic hemodialysis patient: An unusual case of a common disorder

Hamzi Mohamed Amine
Department of Nephrology and Dialysis, 5th Military Hospital of Guelmim, Guelmim, Morocco

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Date of Web Publication

12-Jan-2017

How to cite this article:
Amine HM. Tophi as the initial manifestation of gout in a normouricemic hemodialysis patient: An unusual case of a common disorder. Saudi J Kidney Dis Transpl 2017;28:194-5

How to cite this URL:
Amine HM. Tophi as the initial manifestation of gout in a normouricemic hemodialysis patient: An unusual case of a common disorder. Saudi J Kidney Dis Transpl [serial online] 2017 [cited 2022 Aug 19];28:194-5. Available from: https://www.sjkdt.org/text.asp?2017/28/1/194/198278

To the Editor,

A 68-year-old woman on long-term intermittent hemodialysis (HD) for end-stage renal disease (ESRD) secondary to hypertension presented with three subcutaneous nodules around the metatarsophalangeal joints of both hands (approximately 2 cm in diameter) that appeared three months ago and the size of which had increased rapidly in the recent weeks. A nodule on the right hand showed inflammatory signs with a small skin erosion ([Figure 1]). X-ray of both hands showed soft tissue swelling with no areas of bone erosion or calcification. There was no sign suggesting arthritis. Blood tests showed a serum uric acid level of 5.4 mg/dL with moderately elevated C-reactive protein (16.2 mg/dL). The diagnosis of gout was confirmed based on the presence of monosodium urate crystals in tophi aspirate analysis. We initiated treatment with allopurinol 100 mg per day and topical antibiotics to allow tophi reduction, which resulted in relief of the patient's symptoms and all tophi eventually resolved after three months of allopurinol treatment. The HD regimen was not changed (4 h three times a week) since the delivered dose of dialysis was adequate.

Figure 1. Tophi over the interphalangeal joints in both hands of the patient.

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Gout is a metabolic disorder usually associated with hyperuricemia caused by the deposition of monosodium urate crystals in and around joint tissue. The incidence of gout in ESRD patients is believed to be rare after the initiation of renal replacement therapy.^{[1] ,[2]} Gout is believed to occur more commonly in predialysis patients with chronic kidney disease (CKD) as well as renal transplant recipients compared with patients treated with dialysis. Studies suggested that an episode of gout in ESRD was independently associated with a 1.5 fold increase in mortality risk.^[3]

The development of tophi in the absence of prior episodes of gouty arthritis is unusual. In a review of literature by Wernick et al, a total of 32 cases were reported.^[4] Patients with tophi as the first sign of gout were older, predominantly female, and most of them had CKD. In addition, they had predominant or exclusive finger involvement. There is no clear explanation for the absence of gouty arthritis in the presence of tophi.

Tophi gout should be considered in HD patients despite the presence of normal or even decreased serum urate concentrations. The exact mechanism of this paradox, however, remains unclear. It is possible that antioxidant uric acid becomes increasingly consumed through its scavenging of free radicals that are produced during the inflammatory process.^[5]

Allopurinol is the most commonly used medication for successfully treating gout in dialysis patients and should be prescribed despite normal serum uric acid concentrations. The aim of this urate-lowering therapy is to maintain urate concentration below the saturation point of monosodium urate, as the rate of tophus disappearance is inversely related to uricemia.^[6]

Acknowledgment

We thank Kamal Berechid, for his linguistic review of the manuscript.

References

1.	Ifudu O, Tan CC, Dulin AL, Delano BG, Friedman EA. Gouty arthritis in end-stage renal disease: Clinical course and rarity of new cases. Am J Kidney Dis 1994;23:347-51.
2.	Ohno I, Ichida K, Okabe H, et al. Frequency of gouty arthritis in patients with end-stage renal disease in Japan. Intern Med 2005;44:706-9.
3.	Cohen SD, Kimmel PL, Neff R, Agodoa L, Abbott KC. Association of incident gout and mortality in dialysis patients. J Am Soc Nephrol 2008;19:2204-10.
4.	Wernick R, Winkler C, Campbell S. Tophi as the initial manifestation of gout. Report of six cases and review of the literature. Arch Intern Med 1992;152:873-6.
5.	Waldron JL, Ashby HL, Razavi C, et al. The effect of the systemic inflammatory response, as provoked by elective orthopaedic surgery, on serum uric acid in patients without gout: A prospective study. Rheumatology (Oxford) 2013;52:676-8.
6.	Richette P, Bardin T. Gout. Lancet 2010;375: 318-28.