Other Sites of Tophi
Apart from the external ears, tophi are apt to form in various localities. Most frequently they are situated in the vicinity of the joints and bursæ, especially that over the olecranon. As attack follows attack at short intervals the tophaceous matter is heaped up around the joint, and in this way many articulations may be involved, even all of them, says Trousseau, “as happened to Gordius, who composed on himself the following jocular epitaph:—
“‘Nomine reque duplex ut nodus Gordius essem.’”
Uratic deposits sometimes attain a prodigious size. I have seen them the equivalent of a small hen’s egg. The largest tophi are invariably found in the neighbourhood of some joint, and the upper extremities furnish the most marked examples. But even when of considerable magnitude they may be non-adherent, the skin gliding freely over their surface. As John Hunter wrote: “The chalk shall remain for years without producing inflammation, and seldom produces it at all but from quantity.”
Often, however, their presence at length induces irritation of the overlying integument. As they approach the surface the skin assumes a purple hue, becomes thin, and ulcerates. The uratic ulcers thus formed have generally an indolent fungous base. As the deposits extrude or are removed they are continually redeposited, and in this manner ounces of urates may be discharged. The same is followed by great relief and diminution of deformity.
Discussing such lesions, John Hunter tells us that “when the interior surfaces are exposed they hardly take on common inflammation and suppuration, healing more readily than a sore of the same magnitude from any other cause; even a joint shall be exposed, yet common inflammation shall not come on, nor shall it suppurate: only a watery fluid shall come out, bringing the chalk with it occasionally, and it shall heal up kindly.”
A glance, too, at the preceding footnote shows that Moore also agreed with Hunter as to the absence of common inflammation and suppuration. Moreover, even of recent years it has been suggested that, because gouty tophi do not suppurate even when ulcerated through the skin, the urates have antiseptic properties. But Bendix (Zeit. klin. Med., 1902) failed to demonstrate such qualities experimentally. The truth would appear to be that, though gouty inflammation never ends in suppuration, yet abscess formation very commonly occurs in the peri-tophal tissues. Such more often ensues in subjects of frail health or of definitely cachectic type. Garrod saw as many as five or six open at one time in each hand, and others on the feet. In his experience they give rise to but little constitutional disturbance. Scudamore, speaking of the same, says the sores produced are “unusually tender, aching, and sometimes very painful as the fit is making its approach.”
Ultimately the gouty ulcers thus formed dry up, and this indifferently whether or not the uratic deposits are wholly extruded in the discharging pus. The wound then closes, leaving a small scar, which, however, given a fresh attack of gout, is but too likely to break down, and this process may occur repeatedly. Bursal sacs containing tophi not infrequently suppurate, constituting abscesses containing urates.
An interesting fact noted by Garrod was that so long as such abscesses were discharging freely the subjects enjoyed comparative immunity from overt gout. But, given healing of the same, in several instances he had seen it the signal for a sharp outbreak. Duckworth, too, states that “whenever ulceration and flow of tophaceous matter occurs it is rare to meet with paroxysmal attacks anywhere in the body. With the cessation of the discharge renewed fits may intervene.”
While they tend to aggregate themselves round the joints, yet tophi sometimes invade the integument of the limbs. They have been seen in the skin over the ulna and tibia, and commonly over the olecranon and patella. Pye Smith recalls the instance of a man in whom a number of small ulcers, discharging urate of soda, formed in the middle of his thighs and legs. The case is not an isolated one, but the incidence of subcutaneous uratic deposits in the limbs, save over articulations, is exceptional.