ERYTHEMA INFECTIOSUM rubeola (Tschainer), Megalerythema epidemic= (Plachte), Grossflecken (Plachte), exanthema variabile (Pospischill), erythema simplex marginatum (Feilchenfeld), erythema infantum febrile (Tripke), epidemic erysipelas of children (Tripke), fifth disease.
Historic Note.—Dr. Anton Tschamer of Graz in 1886 described thirty cases. In 1S91 Gumplowicz of the clinic of Escherich reported seventeen cases, in 1896 Tobeitz reported some cases at the Congress of Moscow. All these authors, however, regarded the disease as true rubeola or a peculiar type of the disease etiologically identical. During the discussion following the report of Tobeitz, Escherich was the first to regard it as a distinct disease entity. This view was corroborated by his pupil, A. Schmid, who described in detail many points pertaining to differential diagnosis. All cases hitherto reported had been observed in Graz, where erythema infeetiosum had occurred in at least four different epidemics during these years. In 1S99, Sticker observed in Giessen and vicinity a spread of the disease which he held to be as yet unknown in literature. He and his pupil Berberich are the authors of an excellent description of the disease, who also gave it the name here adopted. Reports then appeared from Berlin (Plachte, observations from May, 1900; Feilchenfeld, observations from October, 1901); from Coblenz (Tripke, 1901); from Vienna (Pospischill and Escherich, 1904); from SOlingen (Heiman, 1904); from Munich (Trumpp, 1906); and several reports from Italy, Russia and America. It is a question whether we can class with this disease cases of epidemically occurring " Erythema sim plex seu exsudativum" and "roseola destiva," mentioned by older authors (Gerhardt, \Villan, Bateman, Henoch, Kaposi). The disease is not even to-day well known. Even after 1900 many observers regarded themselves as the first discoverers. In German literature we find about 300 cases.
Characteristics of the infectiosum is an acute, contagious, exanthematous, infectious disease causing but slight consti tutional disturbances. The leading symptom is a polymorphous maculo
papular or confluent erythema (like erythema exsudativum multiforme), involving particularly the face and extensor surfaces of the extremi ties and lasting with remissions and intermissions at least one week.
Occurrence.—The disease occurs in epidemics of moderate severity (most frequently in spring and summer), also at times sporadically. There seems to be an association between epidemics of this disease and epidemics of scarlatina, measles and rubella. It attacks the young at the age of 2 to 18 years, occasionally it occurs in adults, girls are more 325 liable than boys. According to statistics it is rare under the age of 2 to 3 years: it is possible, however, that the disease at this age is not always recognized because it may run a different course. As to its geographic distribution nothing definite is known. Sticker's researches for a specific cause have not proved successful.
Contagion ; Predisposition.—The appearance of a number of cases in certain localities, city districts, schools, institutions and families has repeatedly been shown, nevertheless it seems that either the contagious ness is not great or there exists but little predisposition. Escherich and Pospischill, who have admitted children with erythema infe•tiosum to the public wards, have never observed a case of ward-infection. Accord ing to Sticker the disease is not transmitted by contact with the patient, and Schmid believes that it is not an infectious poison but an obscure something which affects different individuals simultaneously. Accord ing to the writer's observation, however, a patient admitted to the child's clinic at Munich without doubt. infected one assistant and he again another patient of the institution. The period of incubation is said to be from 5 to 14 days, this being the interval between the appearance of the first symptoms among members of the same household, although this period may vary. The incubation stage of the cases observed at the Munich clinic lasted at least 7 and not longer than 17 days.