Multiple Cases of Erythema Nodosum in a Class of School Children.

It is widely, though not universally, accepted that most cases of erythema nodosum in children are connected with tuberculous infection. The frequency of positive tuberculin reactions in children with erythema nodosum almost reaches one hundred per cent. Patients who do not react positively to tuberculin, even in high doses, are insignificant in number: in Dr. Wallgren's statistics here about two per cent. The characteristic moment for the appearance of erythema nodosum in tuberculous infections is the end of the incubation period, when the organism is in an allergic condition; erythema nodosum is a parallergic phenomenon. This circumstance explains the cases in which erythema nodosum appears during the later stage of a tuberculous disease in connection with the measles, whooping-cough, and other illnesses that may produce a passing decrease in allergy; with the ensuing return of allergy, erythema nodosum may sometimes appear. As erythema nodosum appears at the close of the incubation period of tuberculosis, when the children become sensitive to tuberculin, an attempt should be made in these cases to discover visible manifestations of the tuber-culous process, which are to be found in most cases in the form of hilum gland infiltrations, demonstrable by X-rays. Erythema nodosum in children is thus most often a significant symptom suggesting that we are confronted by a recent tuberculous process which must be the object of critical investigation , whether it calls for medical treatment or not. On this point Wallgren expresses the opinion that most children with erythema nodosum, especially before the school age, require careful medical inspection and supervision. It is not the erythema nodosum, but the tuberculous process unmasked by it, that must be treated. The time and nature of the treatment depends on the degree of this affection. A no less important proceeding which the discovery of a fresh tuberculous process should initiate, is the tracing of the source of infection. In cases where the tuberculous infection first appears as erythema nodosum, the task is in so far facilitated that we can more easily determine the approximate date of infection, for erythema nodosum usually shows itself, as we have mentioned, at the end of the incubation stage, and the incubation period for