Dermatology: Practical and Conceptual Observation | Dermatol Pract Concept 2014;4(4):5 33 DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com Introduction Gouty panniculitis is an unusual dermatologic manifestation of gout. The patient may present with subcutaneous nodules or indurated plaques, which may precede or appear subse- quently to the joints involvement of chronic tophaceous gout. Pathogenesis of gouty panniculitis is not fully understood but it has been postulated that overproduction and accumulation of uric acid are triggered by preexisting subcutaneous tissue damage with concomitant localized inflammation [1]. We report a case of gouty panniculitis presenting as extensive subcutaneous involvement with no significant history of gout. Case report A 40-year-old man presented with a 2-year history of wide- spread nontender, firm, and white to yellow nodules and plaques over the trunk, arms, legs, and dorsum of both feet. The patient reported intermittent arthralgia and occasional swelling of both ankles over the past 4 years. The patient denied other concomitant medical conditions, including gouty arthritis or history of alcohol abuse. He reported a negative familial history of gout or renal diseases. Physical examination revealed a body mass index (BMI) of 34 and blood pressure of 140/80 mmHg. Other systemic evaluation was unremarkable except for the Disseminated gouty panniculitis: an unusual presentation of extensive cutaneous tophi Penvadee Pattanaprichakul1, Sumanas Bunyaratavej1, Philip M. McLain2, Supenya Varothai1 1 Department of Dermatology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand 2 University of Texas Health Science Center Houston Medical School, Houston, Texas, USA Keywords: gouty panniculitis, disseminate, tophi Citation: Pattanaprichakul P, Bunyaratavej S, McLain PM, Vorothai S. Disseminated gouty panniculitis: an unusual presentation of extensive cutaneous tophi. Dermatol Pract Concept. 2014;4(4):5. http://dx.doi.org/10.5826/dpc.0404a05 Received: August 15, 2014; Accepted: September 19, 2014; Published: October 31, 2014 Copyright: ©2014 Pattanaprichakul et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: None. Competing interests: The authors have no conflicts of interest to disclose. All authors have contributed significantly to this publication. Corresponding author: Penvadee Pattanaprichakul, M.D., Department of Dermatology, Faculty of Medicine Siriraj Hospital, 2 Prannok Rd, Siriraj, Bangkoknoi, Bangkok, Thailand. Tel. +662.419.7000, ext 4332-3; Fax. +662.411.5031. Email: penvadee.pat@mahidol.ac.th Gouty panniculitis is a rare cutaneous illness characterized by the deposition of subcutaneous mono- sodium urate crystals with lobular panniculitis. Only a small number of cases with gouty panniculitis have been reported in the literature with unclear pathogenesis. In this article, we present a case of disseminated gouty panniculitis in the patient who had never been diagnosed of gout but revealed significant hyperuricemia at the time of diagnosis. ABSTRACT 34 Observation | Dermatol Pract Concept 2014;4(4):5 presence of nodules and plaques with some ulceration covered with a chalk-like substance over all extremities, trunk, and dorsal feet (Figure 1). Clinical signs of arthritis and arthralgia were not appreciated at the time of examination. Upon further investigation, the patient’s serum uric acid was elevated to 12.2 mg/dL (normal range 3.6-7.7 mg/dL). Complete metabolic panel and complete blood cell count were within normal range except for the X-rays of the hands and feet which showed some osteophytes without significant bony destruction. A skin biopsy demonstrated basophilic, amorphous material surrounded by foreign body granulomas, located in the deep dermis and subcu- taneous fat lobules with focal lymphohistiocytic infiltrate (Fig- ure 2A-D). These deposits were negatively birefringent under polarized microscopy. Periodic acid-Schiff (PAS) and acid fast bacilli (AFB) stain were negative for microorganisms. Given the clinical and laboratory findings, the diagnosis of disseminated gouty panniculitis was made. Discussion Gouty panniculitis has been described as a rare cutane- ous manifestation of gout characterized by the presence of monosodium urate crystal deposition in the subcutaneous tissue with predominantly lobular inflammation [1]. While an association with elevated serum uric acid levels is evident, our current knowledge of the pathogenesis is incomplete [1,2]. Pre-existing tissue damage induced by venous stasis Figure 1. Extensive cutaneous nodules and plaques over trunk and extremities. (Copyright: ©2014 Pattanaprichakul et al.) and micro-trauma may play roles. Literature review suggested that gouty panniculitis can occur before or after the develop- ment of classic tophaceous gout. Gouty panniculitis clinically presents as indurated nodules or plaques with an irregular surface, found predominantly on the lower extremities with a tendency to ulcerate and drain a chalk-like substance [1,3-5]. Unlike previous reports, our case demonstrated extensive skin lesions found not only on the lower extremities, but over the trunk and upper extremities. The condition has been reported to be related with the elevation of serum uric acid level in chronic tophaceous gout with a suboptimal treatment as a risk factor for the development and progression of gouty pan- niculitis [1]. In our case, the diagnosis of disseminated gouty panniculitis was made according to a combination of general- ized cutaneous lesions and histopathological findings of deep dermal and subcutaneous deposits of amorphous material with needle-shaped spaces surrounded by granulomatous reaction with doubly refractile crystals and negative bire- fringence under polarized microscopy. However, in our case, we did not perform an alcohol-fixed skin biopsy to demon- strate the more prominent, brownish, negative-birefringent, needle-shaped crystals under polarization as another helpful diagnostic method to detect urate deposits. Differential diag- nosis of widespread gouty panniculitis includes other crystal deposition disease, such as pseudogout and oxalosis. For pseudogout, translucent, rhomboid and rod-shaped crystals with blunt ends showing positive birefringence under polar- Observation | Dermatol Pract Concept 2014;4(4):5 35 ization are characteristic findings [6]. Cutaneous oxalosis demonstrates the yellow-brown crystals or blue birefringence under polarized light in the patients with chronic kidney disease with chronic dialysis and cutaneous involvement of oxalosis as the result of vascular complication such as livedo reticularis, acrocyanosis and peripheral gangrene in the set- ting of hyperoxaluria [7]. We believe the presentation of our patient, both clinical and histopathological, is similar to the previously proposed term “gout nodulosis” [8]. Obesity, chronic venous insufficiency, long-term use of furosemide and glucocorticoids are considered to be the risk factors for cutaneous deposit of uric acid [4, 5]. Therefore, obesity was considered to be the possible risk factor for the development of gouty panniculitis in our case. There is no specific therapy for gouty panniculitis. Some reports noted improvement of skin lesions following systemic treatment for hyperuricemia. High-dose allopurinol 600- 1,200 mg/day and colchicine have been reported to improve the lesions of gouty panniculitis and prevent formation of new lesions [3]. Our patient was treated with allopurinol 600 mg/day, which resulted in the gradual improvement of skin lesions over 3 months period. Serum uric acid level decreased to 8.4 mg/dL over 6 months period and there were no epi- sodes of arthritis or arthralgia at the latest follow-up visit. Conclusion Disseminated gouty panniculitis is an extremely unusual presentation of cutaneous tophi and may not be apparent to the physician in early stages of its development. Clinical suspicion should be taken in patients with known history of gout or long-standing hyperuricemia with the onset of new cutaneous lesions as described. Acknowledgment The authors would like to thank Dr. Punkae Mahaisavariya for her valuable comments and suggestions upon the prepara- tion of this case report. References 1. Ochoa CD, Valderrama V, Mejia J, et al. Panniculitis: another clini- cal expression of gout. Rheumatol Int. 2011; 31:831-5. 2. Wernick R, Winkler C, Campbell S. Tophi as the initial manifesta- tion of gout. Report of six cases and review of the literature. Arch Intern Med. 1992; 152:873-6. 3. Dahiya A, Leach J, Levy H. Gouty panniculitis in a healthy male. J Am Acad Dermatol. 2007; 57:S52-4. 4. LeBoit PE, Schneider S. Gout presenting as lobular panniculitis. Am J Dermatopathol. 1987; 9:334-8. 5. Wang L, Rose C, Mellen P, Branam G, Picken MM. Gouty pannicu- litis with ulcerations in a patient with multiple organ dysfunctions. Case Rep Rheumatol. 2014; Epub 2014 Jun 15. 6. Shidham V, Chivukula M, Basir Z, Shidham G. Evaluation of crystals in formalin-fixed, paraffin-embedded tissue sections for the differential diagnosis of pseudogout, gout, and tumoral calcinosis. Mod Pathol. 2001; 14:806-10. 7. Blackmon JA, Jeffy BG, Malone JC, Knable Jr AL. Oxalosis in- volving the skin: case report and literature review. Arch Dermatol. 2011; 11:1302-5. 8. Iglesias A, Londono JC, Saaibi DL, Pena M, Lizarazo H, Gonzalez EB. Gout nodulosis: widespread subcutaneous deposits without gout. Arthritis Care Res. 1996; 9:74-7. Figure 2. (A) Lobular panniculitis with amorphous material in deep dermis and subcutis (H&E, x40). (B-D) Foreign-body granulomatous inflammation surrounding crystalline deposits [H&E; (B) x100, (C) x200, and (D) x400]. (Copyright: ©2014 Pattanaprichakul et al.)