# Skin Diseases of Children/Erythema Nodosum

​its treatment, and the physician is often in a position to advise against the premature marriage of syphilitic patients, and thus prevent an amount of misery and suffering which he could never cure.
In the treatment of infantile syphilis a half-grain or more of mercury with chalk may be administered three times a day, and a speedy improvement expected if the child is properly cared for. When irritability of the stomach and intestines is present it is advisable to adopt the plan of mercurial inunctions. A mass of mercurial ointment, the size of a small marble, should be spread upon a piece of flannel and bound around the trunk or thighs, its position changed from day to day to prevent excessive irritation of the skin.
In treating mucous tubercles and superficial ulceration upon the buttocks and about the genitals, calomel powder mixed with three to five parts of starch may be sprinkled over the raw surface, care being taken to keep the affected parts dry and clean. The importance of fresh air and nutritious food must never be forgotten, and when the symptoms of the disease have abated the syrup of iodide of iron, and perhaps cod-liver oil, may usually be given with great benefit.
Erythema nodosum is one of the forms of erythema multiforme, though commonly described in dermatological text books as a distinct disease. It occurs most frequently in childhood, and the female sex seems especially prone to suffer from it.
The lesions in this affection are red, painful swellings, looking very much like recent contusions, and are most frequently seen over the tibiae. They are usually associated with slight fever, considerable malaise, and in some cases with articular pains. Both legs are commonly affected, and rarely are the lesions found elsewhere. In some cases, however, the lesions are numerous and found upon the thighs as well as the legs (Fig. 54), and in rare instances the forearms may be affected. The lesions are at first of a bright-red hue, but soon become dull red or purplish, and usually disappear in a week or two. New lesions sometimes continue to appear and prolong the duration of the disease. The individual nodules usually last from eight to fourteen days. New nodules appear, as a rule, during the first two weeks, and the disease may therefore last from three to six weeks. In exceptional cases it may continue for months.
The cause of erythema nodosum is obscure. Most patients appear to be in poor condition, and a rheumatic tendency is ​sometimes noted. An examination of the blood will sometimes reveal the presence of malarial organisms.
The eruption always tends to a spontaneous recovery and usually shows no disposition to recur. While no medicinal treatment is absolutely necessary, a saline laxative at the outset will often do some good, and may be followed by the administration of salicylate of soda.
Locally a lead-and-opium wash, or a lotion of zinc oxide in lime water, will tend to allay the burning pain or tenderness of
Fig. 54.—Erythema nodosum.
the lesions, which is often a distressing symptom, and rest in bed for a few days is desirable during the height of the attack.
Purpura, or idiopathic hemorrhage into the cutaneous tissues, results from many causes and occurs in connection with various diseases. It is usually characterized by small petechial or larger guttate spots, which are at first of a bright claret hue, but which rapidly assume a dull-purplish color. The eruption is readily distinguishable from an erythema or any inflammatory exanthem, since the redness does not disappear under firm pressure of the finger.
In purpura simplex the lesions are commonly symmetrical and seen upon the legs, but in children more frequently than