Definition And Description

Zoster is an affection characterized by the development of a cluster or clusters of moderate or large sized vesicles on a circumscribed patch or patches of inflamed skin. When there are two or more patches, they are arranged in a line, and the line follows the course of the principal nerve-trunk supplying the part. The portions of integument most frequently affected are those which are supplied by one of the intercostal nerves. The regions supplied by the branches of the fifth pair of cranial nerves, the sciatic, the anterior crural nerve, and the nerves of the shoulder, arm, and forearm, are also not unfrequently affected. The affection sometimes commences with a sharp neuralgic pain in one of the regions mentioned. A few days or weeks later the patient finds a little erythematous patch which is slightly sore, the pain being usually of a burning character. A few hours or a day later another patch of the same sort is met with over the course of the affected nerve, and then others, to the number of five or six, may appear. Shortly after its appearance the first patch becomes studded with vesicles from five to twenty in number, and the other patches in turn become affected in the same manner. When the eruption is fully out, the neuralgic pain sometimes disappears. In other cases it continues, and may even become more severe. The vesicles at first contain a clear and transparent serum, which, however, may soon become opaque. If the vesicles are ruptured the corium is exposed, and the fluid, if not removed, concretes into a brownish crust. If the vesicles are not ruptured they persist for a week or ten days, when their contents begin to undergo absorption, leaving an adherent scale or scab which finally drops off, leaving a reddened, and perhaps slightly depressed macule, that in time fades away. If the implication of the skin has been very superficial, no scar results. In many cases, however, the morbid action extends more deeply, and small, white, depressed scars remain to mark the site of the disease. If the neuralgia have persisted up to this time it may now cease, or, as in some cases, persist indefinitely, even for years.

If Zoster attack a scrofulous subject, or one of advanced age, or in a depraved state of health from any cause, the affection may, in its local manifestations, become much more severe. The vesicles, on rupturing, may be followed by ulcers of a more persistent character. Sloughing may occur and death has sometimes resulted from the disease.

One marked peculiarity of Zoster is the occurrence of the disease on one side only, the region supplied by the corresponding nerve of the other side being unaffected. Cases of double Zoster have Msi), though rarely, observed. Another peculiarity connected with the disease is the fact that it, like the eruptive fevers, attacks the patient but once in his life. A few cases of recurrent Zoster, however, have been recorded.

Diagnosis

The diagnosis of Zoster is, as a rule, exceedingly simple. It can only be mist for one of the forms of herpes or hydroa, The characteristic features of Zoster have just been pointed out, and the differential diagnosis between it and herpes are discussed in connection with that disease.

Prognosis

The prognosis of Zoster is usually good; that is, in the majority of cases the patient will entirely recover from the effects of the disease in from two to four weeks. In a few cases the persistent neuralgia may prove very difficult to relieve. In one instance I met with a localised pruritus, occupying the site of a previous Zoster, that resisted treatment for a year, when I lost sight of the case. In another patient whom I saw but once, severe and constant neuralgic pain had lasted for two years and a half, and, in addition, intense hyperaesthesia was present, to that the slightest pressure on the scars of the old eruption caused intense suffering. The sound integument between the scars was not hyper-aesthetic. In aged and feeble persons, and those in depraved health, the prognosis should be guarded.

Etiology

There is little doubt that in all cases of Zoster, the nerve which marks its distribution will be found in a diseased condition. In fact, whenever an opportunity has been afforded of examining the nerve this has been found to be the case. In cases of thoracic Zoster, besides the nerve-trunk, the ganglion attached to its posterior root has also been found diseased, and was apparently the starting-point of the trouble. In like manner the Gasserian ganglion has been involved in Zoster, affecting one or more of the branches of the tri-facial nerve. Zoster of the chest-walls has also been met with in connection with intra-thoracic morbid growths; and I have once seen it associated with a circumscribed dry pleuritis. An eruption of Zoster has also been noticed in patients during a course of arsenical medication; I have seen two such cases. From the foregoing it will be seen, that while there is no doubt as to the connection between the eruption and the underlying nerve, the nature of this connection is by no means clear.

Treatment

If the patient be in other than apparent good health, the first care should be concerning his hygienic surroundings. Good air, food, etc., should be secured if possible, and if the patient suffers sufficiently to make repose in bed a desideratum, this should be not only permitted, but encouraged. In severe cases it should be insisted on, even if the patient thinks that his business or other duties require him to be up and about.

If febrile action is present, and it sometimes is for the first day or two of the eruption, this should be met by the use of Aconite or Gelsemium. The next point to be considered, is whether there are any drugs that, internally administered, are capable of aborting the eruption or of shortening the periods of its evolution and decline; of relieving the tenderness and soreness, or the accompanying neuralgia. The drugs that would naturally occur to us in this connection are those belonging to the class "neu-rotica," as aconite, caffein, gelsemium, ignatia, nux vomica, phosphorus, phosphide of zinc, rhus toxicodendron, quinine, etc. Of these phosphide of zinc is strongly recommended by Thompson, as capable of shortening the duration of the disease, and relieving the accompanying neuralgia. Bulkley also uses the phosphide of zinc, but as he combines it with nux vomica (110, 2: 158) it is difficult to say which drug deserves the credit. Rhus toxicodendron is recommended by my friend, Dr. Sturgis. I have also employed it, but am undecided as to its value. Quinine and nux vomica are advised by most writers on "general principles," and are doubtless of some value. Aconite and gelsemium I have personally found of value.

Kaposi (198, 324) states that he has derived benefit from the use of Arsenic.

When the pain is excessive, and uncontrolled by other agencies, opium or hypodermic injections of morphia are indicated.

The local treatment of Zoster deserves attention. Electricity, both in the form of the constant and the induced current, has been credited with the power of aborting the eruption. My own experience on this point has not been decisive. Later, however, electricity, especially the constant current, is of service in connection with the neuralgia and in promoting the cicatrization of the ulcers, when they exhibit an atonic aspect. The principal indications, however, are to protect the vesicles from rupture, and to relieve the soreness that is usually present, and is increased by rupture and exposure of the unprotected and sensitive surface to friction from the garments, etc. The method most in vogue is to gently apply a coating of oil to the surface, and over that dust a thick layer of powdered starch. To the starch a little opium may be added, if necessary. Another good protector is collodion, which may be rendered sedative by the addition of a little fluid extract of belladonna, or the eruption may be covered with an adhesive opium or belladonna plaster spread upon linen.

If, on rupture of the vesicles or falling of the crusts, irritable or indolent ulcerations are exposed, they should be treated just as similar conditions, arising from other causes, would be.