Although erythema nodosum is usually included amongst the varieties of erythema, it is right to say that the affection is looked upon by some observers as a specific illness which ought properly to be classed with en teric fever and the other varieties of acute specific disease. By others the complaint is supposed to have a distinct connection with the rheumatic constitution, and there is no doubt that it often attacks the subjects of rheumatism.
The appearance of the rash is often preceded by pains in the limbs and lassitude. The spots themselves are large oval patches or swellings of a rosy red tint, and measure from one to three or four inches in their long diameter. They usually occupy the front of the legs and are accom panied by some tenderness. At first they are hard, but after a day or two become softer, and may even give a sensation of semi-fluctuation to the finger. At the same time the colour grows more and more purple until it finally disappears, leaving a yellow discolouration of the skin. The patches are almost always present on both legs, and sometimes attack the forearms as well, or even other parts of the body. Their number is usually eight or ten.
Each swelling goes through the changes characteristic of a bruise, always turning first purple, then yellow, and lasts for two or three weeks. The duration of the complaint is, however, often much longer ; and con valescence may be considerably delayed by the appearance of successive crops of the nodose patches.
A little girl, aged twelve years, was a patient in the East London Chil dren's Hospital. The girl had been suffering for nine weeks from succes sive crops of large red blotches which occupied the forearms and legs. There were also a few on the belly. They began as small red spots, which grew larger and became elevated and swollen. Their colour afterwards became purple and they then faded away like a bruise. The child was said to have had a similar attack two years before. She had complained for a fortnight of pains in the joints, and her knee had been swollen for a week or ten days.
While the patient remained in the hospital various joints were in turn swollen and painful. After the knee had recovered the right wrist became affected, and later the articulation of the jaw on the right side was painful.
Afterwards, the pain and swelling returned to the wrist. There were no signs of cardiac mischief ; and the temperature was always normal in the morning, rising at night to between 99° and 100°. She was said never to have had rheumatic fever. Her urine was normal.
The child took iodide of potassium, quinine and iron without benefit, but improved directly the treatment was changed to drachm doses of oil of turpentine. Under this remedy she quickly recovered her health. The medicine produced little aperient action on the bowels.
According to M. Germain See, erythema nodosum is apt to be compli cated by disorders of the respiratory apparatus, especially pleurisy and broncho-pneumonia.
nodosum cannot be mistaken for any other form of eruption. The large oval soft swellings seated upon the front of the legs, their tenderness on pressure, and the successive changes of colour, such as is characteristic of a bruise, which the swellings undergo in their progress to recovery, can leave little doubt as to the nature of the com plaint. In purpura bruise-like patches are often seen, but the spots are much smaller, are not elevated, are accompanied by no tenderness, and are not altered in colour by pressure of the finger. Moreover, that dis ease is often accompanied by haemorrhages, which are never seen in un complicated erythema nodosum ' • and the large bruise-like patches- on the skin are mixed up with small. deep-red peachire. It must be remem bered, however, that the two diseases may occur together, for erythema nodosum is an occasional complication of purpura.
Treatment.—The patient should be kept in bed and be treated with quinine ; and the bowels should be kept regular with mild aperients. No local treatment is required unless the tenderness of the patches and the pains in the limbs form a subject of complaint. In that case the limbs may be wrapped in cotton-wool. In the more chronic cases where succes sive crops of swellings appear, oil of turpentine may be given, as in the case narrated above, in doses of one or two drachms three times a day. The child may have meat once a day, but no potatoes or sweets should be allowed while the pains continue troublesome.