Among the more frequent complications may be mentioned migraine, certain cutaneous affections, more especially psoriasis, prurigo, lichen, and some diseases of the eye, chiefly iritis, which is apt to be relapsing, and sometimes episcleritis. It is remarkable that iritis very seldom occurs as a complication of acute articular rheumatism.

The so-called rheumatic nodules occur also in chronic rheumatoid arthritis. It is not yet established that they are peculiar to rheumatism and to rheumatoid arthritis. Dr. Stephen Mackenzie has seen them in one instance in tertiary syphilis, the patient not having had arthritis, rheumatism, or chorea.

2d. The partial or oligo-articular form of rheumatoid arthritis, like the general or polyarticular variety, is usually a primarily chronic affection, insidious in its invasion and slow in its progress. It is chiefly observed in old persons, especially men (senile arthritis), affects frequently a single joint, and chiefly the hip, but occasionally the knee, shoulder, or spinal column, either as a consequence of special injury or of the wear and tear of life, or exposure to cold and wet, or even of what seemed to be simple acute or subacute articular rheumatism or gonorrhoeal rheumatism. When not the result of injury, two or three joints may suffer, both hips or knees, or hip and some of the vertebræ, hip, knee, and ankle of the same limb, and so on. Even in those cases in which the disease for a long time is confined to a single joint and may have been caused by an injury,226 other joints, finally, are apt to become affected, often in a symmetrical order. So that it may seem almost general, or at least polyarticular, just as the converse sometimes happens in the general rheumatoid arthritis of long standing, where the disease becomes greatly aggravated in one articulation and produces great deformity and destruction of it, the others remaining as they were.

226 See Ord's case, II., Brit. Med. Journal, i., 1880, 158.

The symptoms of this partial chronic form are very much those of the general form already described, but there is usually in the early stages less heat, tenderness, and swelling of the affected joint; the pain is less acute, but more abiding, and, with the exception of more or less stiffness or impeded movement in the joint, it may be the only sign of disease present, so that at this stage of the affection it may be taken for simple chronic articular rheumatism. But the disease persists; the voluntary movements become more painful and difficult; slight exercise of the joint is followed promptly by fatigue and aggravation of the pain, and yet the articular surfaces may be pressed together, and flexion and extension be practised, without causing much suffering. Slowly and continuously alterations take place in the affected articulation; with but little heat or redness it enlarges steadily, the soft parts becoming infiltrated and thickened, or effusion taking place into the capsule; the articular surfaces become irregularly depressed by the growth of osteo-cartilaginous rings, osseous nodosities, and stalactiform processes upon them, and these irregularities, together with one or several loose bodies, may be felt in the joint. The enlargement of the articulation becomes more apparent, owing to the wasting of the muscles of the limb; its movements become more and more restricted and difficult, although perhaps not more painful, and are attended with creakings and gratings perceptible to the ear and hand; and at last nearly all movement of the joint may be prevented by the alterations in the shape of the epiphyses, or by the interlocking of the osseous outgrowths, or in rare cases by actual union of the bones. This form constitutes, par excellence, arthritis deformans. In many instances there is little effusion throughout the process, notwithstanding the grave deformity in progress; hence the term dry arthritis. Even the partial form is sometimes more active in its invasion, as when it very rarely succeeds acute or subacute articular or gonorrhoeal rheumatism, or, more frequently, follows an injury.

The duration of the partial form is usually very protracted; it may be ten or twenty years. Exacerbations of the disease occur from time to time, in the intervals of which the patient may be free from pain, although the affected joints are seriously crippled.

The affection is not in itself fatal; the patient may attain an advanced age and die of some intercurrent disease, such as dysentery, pneumonia, cerebral hemorrhage, or other affection incident to old age.

A description of the features presented by partial rheumatoid arthritis affecting the hip (morbus coxa senilis), the shoulder, and other joints rather appertains to works on surgery, and only a glance at the evidences of the disease in the vertebral column (spondylitis deformans) will here be given. When the cervical vertebræ are implicated the power of rotating the head from side to side is usually preserved and is attended with a crackling noise, while the rest of the cervical region is stiff and the head cannot be bent forward; when the dorsal or lumbar vertebræ suffer the back becomes bent, the patient stoops greatly and cannot stand erect, and his body is shortened and more or less twisted. A careful examination will discover not only the great rigidity of the spine, and as it were fusion en masse of its joints, but in these persons the bony outgrowths may be felt. Occasionally the alteration in the vertebræ by compressing the cord or its membranes, or the spinal nerves and ganglia, may produce neuralgic pains in the cervical, dorsal, lumbar, or sciatic nerves, wasting of the muscles, more or less paralysis, and even vasomotor disturbances.

3d. Heberden's nodosities are certainly sometimes the effect of rheumatoid arthritis, implicating chiefly, often solely, the distal joints of the fingers, where it slowly forms two little hard nodules about the size of dried peas upon the side of the articulations. These are notably enlarged and their movements impaired, but pain is seldom experienced, and were it not for deviation of the end of the finger to one side or the knob-like excrescences upon the joints—appearances which much disfigure the hand—patients would not speak of the affection. In many cases these alterations likewise involve, but in a minimum degree, the first phalangeal articulations, and less frequently the metacarpo-phalangeal, and even some of the larger joints—the wrist, knee, or hip, etc. Like the other varieties of rheumatoid arthritis, this form occasionally has a more active invasion than is above mentioned, and may be attended by local pain, heat, and redness, or such symptoms may occur as exacerbations of the chronic disease.

Gout may precede these nodosities, or, as in the case of Charcot's,227 the latter may precede the former by several years. Finally, Charcot remarks that Heberden's nodosities are "often accompanied by asthma, migraine, neuralgia, especially of the sciatic nerve, and muscular rheumatism, and that these manifestations may alternate with the exacerbations of the disease."