[Footnote 121: See J. K. Mitchell, _Am. Jour. Med. Science_, vol. viii., 1831, and _ib._, 1833; Scott Alison, _Lancet_, i., 1846, 276; Brown-Séquard, _Lancet_, i., 1861; Gull, _Guy's Hosp. Repts._, 1858; Charcot, _Archives de Physiologie_, t. i. p. 396, 1868, and many others.] Acute articular rheumatism in children presents peculiarities. It often affects but one joint, and has little tendency to become general; the joints of the lower extremity, ankle, and knee are most obnoxious; the local signs of inflammation, redness, swelling, and pain, are feebly developed, and the child may walk as if nothing were wrong; the disease is usually subacute; the temperature rarely very high; the perspiration not profuse; the urine not scanty, and not often loaded with lithic acid. Cardiac and the other internal complications, except the cerebral, are more frequent than in adults; endocarditis is especially frequent, pericarditis and pleuritis not rare. It is almost exclusively in childhood that acute articular rheumatism becomes associated with or followed by chorea, and yet the delirium, coma, and convulsions frequently observed during rheumatic fever in the adult are very rarely seen in the child. Muscular rheumatism, however, in the form of torticollis, frequently coexists, and so do erythema nodosum and the subcutaneous fibrous nodules previously described. Mono- or Uni-Articular Acute and Subacute Rheumatism. It is very rarely indeed that acute rheumatism invades a single joint to the exclusion of the rest; and it is perhaps impossible to be certain that such an arthritis is rheumatic unless some of the other symptoms or complications of articular rheumatism supervene, or unless it have succeeded a polyarticular rheumatism, which it very rarely does. Mono-articular rheumatism is very generally of the subacute type, and unattended with fever from the outset, or only a moderate pyrexia obtains for a few days; there is generally considerable effusion into the joint, with {50} swelling, pain, and moderate local heat; visceral complications very rarely arise, but the local inflammation persists most obstinately for six or eight weeks or three or four months, and often leaves the joint tender, stiffs, and weak for a long time or even permanently. In both the acute and subacute forms, before concluding that the uni-arthritis is rheumatic, we must exclude the probability of its being traumatic, strumous, syphilitic, gonorrhoeal, neurotic, or, above all, of the nature of rheumatoid arthritis, which many such cases really are.