Differentiation of Uratic Deposits in Gout and Nephritis
Uratic deposits, it is true, occur in both these disorders. But it is with a difference. In gout the uratic deposit assumes the form of tophi, whereas in nephritis it is not so. In the latter the uratic deposit is in the nature of a passive deposition—an uratic incrustation of the articular cartilages.
Again, in gout the deposition is sudden and associated with an acute paroxysm; while in nephritis it is gradual and unassociated with inflammatory reaction.
In gout the uratic deposits are overt, manifest as tophi; in nephritis, occult and unrevealed (ante-mortem).
Uratic deposits in the form of tophi occur in gout, in the absence of clinically recognisable interstitial nephritis. But tophi do not occur in nephritis if uncomplicated by gout.
In conclusion, the mere fact that uratic deposits affect such widely disparate forms in these two disorders is to our mind a sure indication that their mode of origin and formation is equally diverse—the one vital, biological; the other passive, mechanical.