Multiarticular tophaceous gout with severe joint destruction: a pictorial overview with a twist.

Tophi are the visible dermatological signs of gout. A case of tophaceous gout in a middle-aged man with no other metabolic derangement is being presented with multiple tophi on the hands and feet overlying joints as well as on the fingers and toes. We thought it to be of educational value to demonstrate needle-like crystals of urate by polarizing microscopy. X-rays of hands and feet showed dramatic destructive changes. The patient presented with mottled hypopigmentation on anterior and posterior knees and dorsa of hands and feet where he applied hot "aankda" leaves and covered them with bandage resulting in irritant dermatitis with postinflammatory hypopigmentation. This proved to be a red herring in this case.

What was known?

Gout is a metabolic disease with hyperuricemia as the single most important risk factor.

Tophi are the most commonly seen feature for which dermatologists are consulted at times.

Polarizing microscopy is the best method for detecting monosodium urate crystals which is not routinely done by dermatologists.

Antigout medication in acute phase includes colchicine, nonsteroidal anti-inflammatory drugs, and steroids. In chronic gout where the aim is to reduce levels of uric acid in body, probenecid, allopurinol, and febuxostat are commonly used.

Introduction

Dermatologists are not consulted for gout unless there is a visible sign, namely tophi. Tophi are the most commonly seen dermatologic presentation of gout. We describe herein a 46 year old man with no other metabolic abnormality presenting with multiple tophi on the hands and feet. He had an unusual mottled hypopigmentation of both anterior and posterior knees as well as that of dorsa of the hands and feet. Chalky material was expressed easily from one of the tophi and was subjected to polarizing microscopy which revealed classic birefringent needles of monosodium urate. X-rays of his both hands and feet showed multiple juxta articular soft tissue shadows representing tophaceous material. There was classic erosive destruction seen of the bones near the affected joints. There was also subluxation of proximal interphalangeal joint of the second finger of the right hand which is very rare in gout. The red herring was the mottled hypopigmentation which had occurred due to post inflammatory phenomenon. The patient was applying ‘aankda’ leaves after heating them and then tying a bandage around them. He was put on allopurinol and NSAIDs but could not afford any corrective surgery for his hands and feet due to lack of resources.

A 45-year-old man, a fruit cart puller by profession, was referred to this clinic by a nephrologist for multiple nodules on his hands and feet and mottled pigmentation on knees, popliteal fossae, and dorsa of hands and feet with a diagnosis of multiple renal calculi and raised creatinine. He was vegetarian and a teetotaler. He was normoglycemic and normotensive. He had multiple asymptomatic skin-colored nodules overlying joints and many of them were superficially located [Figure 1]. Smaller ones were grouped on the dorsolateral aspect of the fingers and toes and had a yellowish white look. Patient said that one on the right index finger had spontaneously burst twice exuding a thick white chalky discharge [Figure 2]. There was no clinical evidence of psoriasis or psoriatic arthritis. There was mottled pigmentation on his knees, popliteal fosseae, [Figure 5a and 5b] and dorsa of hands and feet. His joint complaints started about 6 years ago with pain in the knees and then on the wrists, fingers, and toes. An initial diagnosis of osteoarthritis was made and he was prescribed diclofenac and paracetamol. During the acute bouts of arthritis he applied heated leaves of ‘aakda’ plant (calotropis gigantea) on his feet, hands, and knees; is the leaves used by villagers as a pain killer by securing them with a bandage.

Figure 1

First toe of the right foot and second toe of the left foot show tophi. Skin on dorsa shows mottled hypopigmentation

Figure 2

Palmar aspect of the right hand showing multiple yellowish white tophi. Tip of the first fingers shows superficial ulceration

Figure 5

(a and b) Mottled hypopigmentation and depigmentation of both knees anteriorly and posteriorly. Inset shows photograph of ‘aankda’ leaves

His hematologic parameters were normal except for mild anemia and a mildly raised ESR. His serum uric acid was 8.8 mg/dl and serum Creatinine was elevated at 1.99 mg/dl. His creatinine clearance was low at 50 ml/min/body surface area. Electrolytes were normal. Urine examination was normal. His blood sugar and hepatic profile were normal. X-ray of kidney, ureters, and bladder showed multiple bilateral radio opaque renal calculi but no hydronephrosis. Extrusion of chalky white material was done with a 3 mm punch. A polarizing microscopy of the material showed negatively birefringent clumps of needle-shaped crystals characteristic of monosodium urate Figure 6a and 6b. His hands and feet showed juxta articular opacities, marked erosive destructive changes of first metatarsophalangeal joint, and proximal interphalangeal joints of foot and hand with subluxation of the latter, a rare phenomenon in gout [Figures 3 and 4].

Figure 6

(a and b) Dense deposits of needle like monosodium urate crystals and scattered needlelike crystals

Figure 3

Erosive destruction of metatarsophalangeal joint with juxta articular opacities of tophi

Figure 4

Erosive destruction with sublaxation of interphalangeal joint of right middle finger

Since there was a strong family history of vitiligo and the patient worried about the mottled pigmentation being vitiligenous. A detailed history revealed that this was an unusual postinflammatory pigmentary change after the intense erythema induced by the ‘aankda’ resolved. A diagnosis of tophaceous gout with renal calculi, urate nephropathy, and destructive arthropathy was made with postinflammatory depigmentation of sites treated with ‘ankdaa’ leaves. The patient was put on allopurinol for the gout.

Discussion

Gout is one of the oldest metabolic diseases described in the history of medicine.[1] Podagra was described as early as 2640 BC and was described by Hippocrates in fifth-century B.C. as the ‘unwalkable disease’.[2] Hyperuricemia is its single most significant risk factor. Gout is characterized by crystal arthropathy preferentially affecting the great toe (podagra) in the initial phase with severe pain and inflammation but instep, ankle, wrist, finger joints, and knee can also be involved.[13] Untreated gout can affect multiple joints, sometimes bilaterally symmetrically and lead to destructive arthropathy as seen in our patient. Although gout typically causes joint inflammation, it can also cause inflammation in other synovial-based structures, such as bursae and tendons.

Tophi, uncommon lesions for a dermatologist, are collections of urate crystals in the soft joints and soft tissues. The tophus is the pathognomonic feature of chronic gout, and signifies a chronic foreign-body granulomatous response to monosodium urate (MSU) crystal deposits.[134] They tend to develop after about a decade in untreated patients who develop chronic gouty arthritis.[134] However, tophi have also been reported as the first sign of gout.[4] Gout with tophi may develop in persons taking thiazide diuretics and long-term cyclosporine.[134] Tophi may develop earlier in older women, particularly those receiving diuretics.[1] They are usually cream colored to yellowish firm, usually mobile nodules. The overlying skin is often thin and red but the erythema may not be appreciated well in dark people. Bullous tophi have also been reported.[3] They are known to affect the helix of the ear, but they can be found in multiple locations, including the fingers, toes, prepatellar bursa, and along the olecranon, where they can mimic rheumatoid nodules.[1345] Ulceration of tophi has been reported as has been the case in our patient on two occasions.[345] They have also been rarely reported in unusual locations such as nasal cartilage, eyelids, cornea, mitral, and tricuspid valves.[1345] They have been documented to cause erosive intraspinal and paravertebral lesions and carpal tunnel syndrome.[1345] Rarely, a creamy discharge may be present. About 85% of patients upon arthrocentesis demonstrate needle-shaped negatively birefringent monosodium urate crystals under a polarizing microscope.[12345] Subcutaneous nodules are seen in rheumatoid nodules and xanthoma can be ruled out by history, serology, and histology.[1345]

The chances of a patient of gout to develop renal calculi are 1.97 times what one would see in persons with normal uric acid levels.[1] Our patient had gout-induced chronic nephrolithiasis. Apart from nephrolithiasis, acute uric acid nephropathy, and chronic urate nephropathy are other two renal manifestations of gout. And it is also known that reduced creatinine clearance may lead to early tophaceous gout.[6]

Gout is treated most often by internists in this country. Nonpharmacological measures include diet restriction of purines, reducing intake of alcohol, and reducing weight. An acute attack is treated by NSAIDs, colchicines, or steroids. Normalization of hyperuricemia is the aim of treatment in chronic tophaceous gout. Drugs like probenecid favoring excretion of uric acid or allopurinol and febuxostat for inhibiting production of uric acid are used. Surgical removal of tophi is attempted only in the case of severe pain, joint deformities, or physical removal of tophi.

This case underscores the importance of knowing more about tophi, the only lesions of gout that are visible to the naked eye. They are not commonly seen by dermatologists. The prevalence of gout is rising with the changing lifestyle leading to metabolic syndrome and also increased longevity; we may come across more cases of tophaceous gout. Tophi can be debilitating and adversely affect quality of life and productivity of an individual.[15] A rheumatologist, nephrologist, and an orthopedic surgeon would be ideal for comprehensive care of such severe cases, something that may not be easy in developing countries. The mottled depigmentation seen in the areas of application of heated ‘aankda’ leaves was a red herring in this case and was attributed to repeated irritant contact dermatitis leading to hypopigmentation.

What is new?

Gouty tophi can assume huge sizes and rarely exude chalky white granular material.

Polarizing microscopy is the best method for detecting monosodium urate crystals which is not routinely done by dermatologists.

We were able to demonstrate the negatively birefringent crystals with polarizing microscope and have shared striking photographs.

This patient showed extensive joint destruction due to tophi with a very rare feature like subluxation of the proximal interphalangeal joint of the right second finger.

Traditional treatment with leaves of ‘Aankada’ (calotropis giantea) heated on a pan and then applied to the knees, feet and hands caused mottled depigmentation in this case which was a confusing presentation. Calotropis gigantea contains phenolic compounds that may be responsible for contact depigmentation.