The eruption may all come out in one day but as a rule new vesicles appear the next day. Sometimes there are distinct pauses after which new crops of the eruption appear, and these may be accompanied by elevation of the temperature. Thomas notes a case where new vesicles appeared after a month's time but one might question whether this was not a recurrence.
It is well known that eruptions may occur in variola before the appearance of the regular eruption especially when there is chemical or mechanical imitation of some part of the body as from garters, corsets and bandages. Similarly the eruption may be thickly set in varicella especially under bandages, from the irritation of dis charges in poorly-cared-for children, and in the genito-crural region from the irritation of the menstrual flow. The pressure of clothing sometimes causes such an arrangement of the vesicles as to lead to the ap pearance of herpes z us t er, with which it may be mis taken. BOkay (1S92) has re ported a case which was treated as herpes zoster and later in the same family there was an outbreak of varicella. Irritation of the skin may cause varicella to run a much more severe course than would otherwise be the case. Desoil (1S92) had a ease in which the parents of t he child, acting on their own authority, gave it a mustard bath in the prodromal stage. The eruption appeared and there were from 500 to 600 confluent vesicles which sup purated. These healed after about six weeks with very serious scarring.
The number of varicella vesicles is extremely variable. Thomas gives 10 as a minimum number and SOO as a maximum. Sometimes fewer may be noted and a single one may be all that can be found. These cases occur in children's hospitals where there is a house epidemic and where very careful examination of the children is undertaken.
Confluent eruptions may sometimes be observed. In almost every case the confluence of a few vesicles may be noted. There have been numerous reports of cases in which the eruption was confluent. in the same way as in smallpox.
The size of the vesicles also varies greatly. In some cases they are the size of a pin head and Thomas and Henoch speak of "miliary" vesicles. The average size is that of a lentil, and vesicles with an average diameter of 10 min. are not uncommon. They may be the size of a dollar.
(Thomas, Demme) and a case was described in which vesicles 10 cm. in diameter occurred (Geddings, 1SS5). In such cases one has the pemphigus-like or bullous form of varicella which is to be differentiated from the accidental occurrence of and pemphigus, at the same ti me.
Abortive and rudimentary forms of the eruption may be noted in which the exanthem comes to a standstill before vesicles are formed. There may be a simple roseola which disappears. Thom as described this form as Roseolre Varicellosm. It may happen that the eruption goes as far as papule formation and then disappears. Gaillard reported an interesting case in which there were papules in the skin and numerous vesicles upon the mucous membranes. These vesicles occasioned great pain.
The eruption even in mild cases occurs on the mucous membranes but not so regularly as in variola. Comby has made especial studies of the enan them and finds that it usually begins before the exanthem but sometimes at the same time or after it.
Location.—It is noted frequently in the mouth, on the hard palate, the tongue, gums, and also on the tonsils and pharynx. The number of vesicles is usually small and one may find but a single spot but sometimes the vesicles are more numerous than those of the exanthem. One does not often see the vesicular stage of the enanthem as the eruption seems to develop more quickly in the mouth than on the skin. Usually at the time of the first examination of the mouth the covering of the vesicle has been partly or entirely destroyed by the warmth and action of the mouth secretions and one sees instead of a vesicle an erosion varying in size from that of a millet seed to a pea, yellowish white in color and surrounded by a red zone. These can be differentiated from ordinary aphtlm, when remains of the top of vesicles are still present. These seem to give rise to but little discomfort in most children but sonic complain on chewing and swallowing. When the vesicles are numerous and inflamed, and there is a secondary stomatitis, there may be great pain on swallowing, a severe burning sensation in the throat and other similar sensations. Generally the simple lesions heal rapidly and the severer manifesta tions may be favorably influenced by suitable treatment.