Zoster

Zoster is an acute affection characterized by the development of one or more  groups  of largesized vesicles. When there are several of these groups, it will be noticed that they are arranged along the course of one of the larger nerve-trunks whose filaments are distributed to the skin.

The most frequent and perhaps the most typical seat of the eruption is on the chest, where it may form a semi-girdle corresponding to the area supplied by one of the intercostal nerves. Zoster, however, is by no means confined to the thoracic region, but may appear on the abdomen, the face, in connection with the trigeminal nerve, on the shoulders and arms, and on the thighs and legs.

The eruption may or may not be preceded by prodromal symptoms, which may partake of a mild febrile attack of one or two days' duration, or, instead, of a more or less severe neuralgia, without fever; or neither of these phenomena may be present, the eruption itself being the first indication of the affection.


Each group or patch of vesicles may consist of from four or five to a dozen separate, non-confluent lesions situated upon a reddened, raised, and inflamed base. Occasionally the vesicles themselves may be absent, and nothing is to be seen except the circumscribed reddened patch. The several groups of vesicles constituting the typical eruption do not usually appear at the same time, but the patches may appear in succession, so that several days may elapse before all the lesions have developed.

The eruption having appeared, is accompanied with more or less pain of a neuralgic character, together with some soreness of parts if the vesicles rupture. As a rule, the lesions remain intact until after a week or so, when the fluid contents become absorbed, and the uplifted epidermis desquamates, leaving a reddened macule, or in some cases a small cicatrix, to mark the site of the lesion.


A striking peculiarity of zoster is the fact that it is strictly unilateral (with exceedingly rare exceptions). Cases of double zoster, in which both sides of the body have been involved at the same time, have been reported. Another feature of this affection is the extreme rarity of a second attack, resembling in this respect the eruptive fevers.

The neuralgia which precedes or accompanies zoster may exhibit any degree of severity, and may indeed persist for an indefinite period after all symptoms of cutaneous irritation have disappeared. Instead of neuralgia, a more or less intense pruritus may be present, confined to the affected region, and persist for a long time.

As a rule, zoster is an affection of little gravity - that is, in persons who when attacked are in ordinary health. In those, however, who are aged or feeble, the prognosis is not always so favourable, as the vesicles may be followed by more or less severe ulceration. When the eruption appears on the head, and especially in connection with the branches of the trigeminus that are distributed to the eye, ulceration of the cornea, and even destruction of the sight, may ensue.