VARICELLA.
BY JAMES NEVINS HYDE, M.D.
Varicella is an acute disorder of infancy and childhood, in the course of which appears a cutaneous exanthem of vesicular type, accompanied at times by systemic symptoms of moderate severity, terminating in the course of from three days to a fortnight, after the formation of relatively few crusts upon the skin, with occasionally persistent cicatrices.
SYNONYMS.—Eng., Chicken-pox; Ger., Windblattern, Schafpocken; Fr., Varicelle; Lat., Variola notha, seu spuria; Ital., Morviglione.
HISTORY.—The literature of the disease which is now best recognized under the title of varicella has been, in the history of medicine, wellnigh inextricably confused with that of variola. In the latter part of the seventeenth and the early part of the eighteenth century the distinction between typical forms of the two disorders became apparent, and was described by Willan and Harvey in England, and other writers in Germany, France, Holland, and Belgium. Among those who have contributed to its literature may be named Hebra, Kaposi, Trousseau, Simon, Thomas, Güntz, Henoch, Kassowitz, and Boeck.
ETIOLOGY.—Varicella is essentially a disease of early life, occurring almost exclusively in infants and young children. It is a contagious disorder, and at times, especially in hospitals and asylums for children, occurs in apparently epidemic forms. The question relating to the inoculability of the contents of its vesicular lesions is still open, positive and negative results being recorded by different experiments.1
1 The writer has purposely avoided, in the brief space here devoted to the disease under consideration, entering into a discussion of the question respecting the relation sustained by varicella to variola. On one side are the views entertained by the Vienna school of dermatologists, according to which there is but a single virus in these several forms of disease—the variolous poison. On the other are the opinions and the practice, largely based upon the latter, of most English and American physicians, who deny the existence of any relation between the pathological states recognized by them as occurring in two entirely distinct affections.
My personal view may be briefly formulated as follows: Practically and clinically, it is useful to regard these disorders as of a distinct nature. The arguments, however, in favor of such absolute distinction are not irrefutable. There is probably in both forms of disease but a single virus, that of variola; but this, modified by evolution among generations of vaccinated children, has, in this process of natural cultivation or attenuation, produced a malady of tender years whose attacks do not protect from variola and occur irrespective of vaccination.
SYMPTOMATOLOGY.—The period of incubation of the disease cannot be said to be definitely established. At times, without question, an entire fortnight elapses between the dates of exposure and the evolution of the disease, but both longer and shorter intervals have been recorded.
If there be a prodromal stage of the disease, certainly in the vast majority of the little patients it cannot be recognized. During the last month the writer has observed the evolution of the disease in twenty children gathered together in the Chicago Home for the Friendless, no one of whom was recognized as ailing before the eruption appeared. Occasionally the disease is preceded by mild or even severe febrile symptoms, accidents sufficiently common in this class of patients.
The exanthem, commonly the first symptom of the disorder, occurs in the form of reddish puncta, from which rapidly develop rosy-colored maculations, and these become tensely distended, transparent or slightly yellowish vesicles, of the average size of a split pea, though they are occasionally smaller or may enlarge to the dimensions of a bean or small nut. The eruption appears first upon the upper segment of the body, implicating the chest in front and behind, the neck, the scalp, particularly the extremities, and quite sparingly the face also, which may, however, entirely escape. In cases where the eruption is profuse it may be completely generalized, involving largely the trunk and extremities, the lesions, upon the back particularly, being as closely set together as in discrete variola. In many, even the majority, of cases the exanthem is much less profusely developed, not more than a dozen or twenty vesicles springing from the surface.
The vesicles are superficial in situation, the firm papule which precedes the variolous rash being altogether wanting. They are at first transparent, their contents plainly showing through their translucent roof-wall, composed only of the stratum corneum of the epidermis. They are both acuminate and globular, and occasionally rest upon a slightly hyperæmic integument. Umbilication rapidly occurs at the apex, and simultaneously their contents become lactescent and gradually sero-purulent. Occasionally vesicles are transformed into genuine, coffee-bean-sized, pustules. Intermingled with these are often seen illy-developed and abortive vesicles.
By the end of a period lasting from twelve hours to the second or third day involution has usually begun, and the lesions, with and without rupture—more often the latter—desiccate, and are thus transformed into yellowish or yellowish and brown, circular, circumscribed crusts resting upon an apparently unaltered integument. These crusts are often so firmly attached that they do not fall spontaneously before the lapse of from five to eight days. When this exfoliation is ended there are left slightly hyperæmic pigmented patches of corresponding size where the crusts had rested. A destructive process occasionally results upon the surface of the face at the base of such vesiculo-pustular lesions as have formed there, in consequence of which a small depressed and superficial cicatrix is left, which does not differ from that resulting from discrete variola. These scars may be superficially seated and transitory in character, or much deeper and persistent through life.
Throughout the course of the disease systemic symptoms may be altogether wanting, or may occur in a mild, and much more rarely in a severe, type. In some cases the temperature is increased by one or two degrees upon the appearance of the exanthem, and often a febrile movement of moderate grade may persist for forty-eight hours or somewhat longer. Defervescence, however, is always rapid and perfect. In very rare cases there is a subsequent successive new development of scanty vesicles, whose appearance is heralded by mild exacerbations of fever.
Occasionally the vesicles may be recognized upon the mucous surfaces of the lips, inside of the cheeks, tongue, palate, conjunctivæ, and progenital regions of both sexes. Still more rarely the glands of the throat become slightly tumid and painful.
The complexus of symptoms, in the large majority of all these little patients, is that which pertains to a disorder of distinctly mild type. The eruptive lesions are scanty and productive of but trifling subjective sensations. Occasionally they are picked or scratched, and thus become the seat of either pain or pruritus. In the febrile stage the child is noticeably fretful for a period of perhaps twenty-four hours. At the end of that time older children are frequently observed engaged in their customary amusements in the nursery.
Severe types and complications of varicella are in general limited to the little patients who are recognized as suffering from hospitalism. Among these we see erysipelas, severe vaccinal eruptions, lesions of inherited syphilis, and the sequelæ of morebilli and scarlatina, which the disease both precedes and follows.
PATHOLOGY.—The anatomical structure of the lesions in varicella is largely a matter of inference, since there has been but small opportunity of studying the disorder as displayed in sections of the morbid integument. Manifestly, the exanthem is exudative in type, the serum in circumscribed areas lifting the superficial layer of the epidermis from the deeper parts of the derm. Unquestionably, septa occur in typically developed varicella chambers, similar to those seen in variola—a pathological fact which is the corner-stone of the doctrine relating to the unity of the two disorders. The serum contained in these septa possesses an alkaline reaction. The formation of a cicatrix is evidently due to the intensity of the process in certain exceptional lesions, as a result of which the papillæ of the corium are superficially destroyed. These sequelæ are often due to the picking and scratching of the lesions.
DIAGNOSIS.—Varicella is to be distinguished from eczema pustulosum by its mild febrile symptoms, the discreteness of its pustular lesions, the absence of itching, and of infiltration of the skin in patches, and its tendency to symmetrical development.
From impetigo and the impetigo contagiosa of Fox of London it will often be scarcely differentiated. Inasmuch as these disorders are frequently recognized among children suffering from varicella or varicella convalescence, it can scarcely be doubted that these diseases have been in the past often confounded, and that in many cases it is practically impossible to distinguish between them. Decided elevation of bodily temperature, umbilication of symmetrically-disposed lesions, and a rapid involution of the disease point to varicella. The two forms of impetigo occur without fever, are usually scantily developed, and are much more apt to be pustular in type, lacking, moreover, the halo of the varicella lesions. The latter are also, on an average, smaller and more numerous. The two forms of impetigo, finally, never display the generalized eruption of severe varicella. The non-contagious variety of impetigo is much more decidedly pustular in its lesions, and the latter spring from a deeper plane of the epidermis.
As to the eruptions due to vaccinia and vaccination, there can be but little doubt that these also have been frequently confounded with varicella. Efflorescences having origin in this way are very largely impetiginous in type, and the conditions named above are then to be regarded as distinctive differences, so far as any distinction can, under these circumstances, be recognized. Impetigo, impetigo contagiosa, and varicella are all sufficiently common accidents after vaccination. No reliance can be placed upon characteristics described as connected with a certain stuck-on appearance of the crust regarded by Fox as characteristic of the crusts in impetigo contagiosa. In all these vesiculo-pustular disorders of childhood desiccating serum and sero-pus upon the surface result in the formation of crusts which have a similar (so-called) stuck-on appearance.
Variola and varioloid of infants and children are to be distinguished from varicella by the evidence of origin from such contagious maladies; by the occurrence of prodromal symptoms; by the greater rise in temperature during the febrile stage; by the typically papular stage of the exanthem at its outset, and no less typically pustular stage before the occurrence of desiccation; by the confluence of lesions in confluent cases; and by the much longer and evidently graver stadium of the disease. Distinctions between mild varioloid and severe varicella in infancy and childhood will always tax to the utmost the skill of the diagnostician. The sooner it is generally understood that intermediate forms occur which cannot be positively assigned to the one or to the other category, the better it will be for both the profession and the laity. The fact that in the one case there is generation of a variolous poison capable of producing a contagious disease in adults, and in the other a malady which is known to affect children only, renders the decision important. Scattered papulo-vesicular and vesiculo-pustular lesions appearing after a high fever, and pursuing a period of evolution longer than forty-eight hours, should always awaken suspicion. Superficial lesions, on the contrary, distinctly vesicular on the third day, or commingled with minute, very superficial pustules, should be regarded as characteristic of varicella.
The so-called varicella prurigo of Hutchison of London2 includes several of the disorders considered above under the titles impetigo, impetigo contagiosa, and the vaccine rashes. The irritable condition of the skin resulting from several of the exanthemata leaves it prone to the development of a long list of cutaneous lesions, some of them accompanied by pruritus in various grades, to each of which might be given, according to the caprice of authors, a separate name.
2 Lect. on Clin. Surg., Lond., 1878, p. 15 et seq.
PROGNOSIS.—The prognosis of varicella, per se, is always favorable. Only in the hospital cases, complicated by erysipelas and scarlatina convalescence, may grave results be anticipated. The milder attacks may leave persistent relics of their career in the form of one or more depressed and persistent cicatrices, which become less conspicuous as the patient approaches adult years.
TREATMENT.—Varicella is, in a large proportion of cases, successfully treated by domestic management and the simpler remedies familiar to those in charge of the nursery. Confinement for a brief time to the cradle or bed, and a proper regulation of the temperature of the room and of the diet, are usually all that is required. Special remedies may be indicated in isolated cases, but certainly none such are demanded by the varicella. Efforts should be made to protect the face lesions from the traumatism of picking and scratching, with a view to prevent pitting.
Isolation of patients is not requisite, nor any process of disinfection other than that which is incidental to a fresh supply of pure air. Vaccination should be practised alike in the case of children who have and who have not suffered from the disease.