It is seen chiefly in spring and autumn, and is met with in both sexes, but is more common in children and young persons. Its nature is obscure. It is probably due to the same causes that are responsible for erythema multiforme, a disease to which it is very closely allied. The process also is intimately identical with that affection, it being, apparently, merely an advanced stage or modification of that disease. It is to be distinguished from ringworm, erythema multiforme, herpes zoster, pemphigus, and dermatitis herpetiformis. In ringworm the process is more superficial, and usually is less inflammatory, the papules or vesico-papules being scarcely distinguishable; in doubtful cases the microscope will decide. Vesiculation will serve to differentiate from erythema multiforme. The absence of neuralgic pain, the distribution, location, and arrangement of the vesicles, are sufficient to exclude herpes zoster. In pemphigus the size, distribution, arrangement, mode of formation, and course of the lesions are different from herpes iris.
The affection tends to spontaneous disappearance in the course of a week or two; nor does treatment seem to influence materially its course. The bowels should be opened with saline laxatives, and other symptoms treated on general principles. Tonics, especially quinine, are in some cases of value. Locally, dusting-powders, such as oxide of zinc, starch, and lycopodium, may be frequently applied. Cooling, antipruritic, or astringent lotions—such, for example, as those used in acute vesicular eczema—will generally prove grateful.
Herpes Zoster.
Herpes zoster, or zoster, popularly known as shingles, is an acute, self-limited, inflammatory disease, characterized by groups of vesicles with inflammatory bases situated along or over a nerve-tract, and accompanied by more or less neuralgic pain.
As a rule, the cutaneous lesions are preceded, usually for several days, by neuralgic or burning pains in the part, and in some cases mild febrile disturbance. An inflamed state of the skin, in the form of one or several patches, is seen, which is soon followed by the formation of vesico-papules, which rapidly become distinct vesicles. They vary in size from a pinhead to a pea, are situated on inflamed bases, and are irregularly grouped. They may occur in small numbers, or, as is usual, be numerous, in which case they are crowded together. In the latter event they may coalesce here and there, forming larger lesions or irregular patches. They continue to appear for five or six days, remain stationary a short time, and then begin to subside. One or more groups may be present; usually a half dozen or more are seen in the one case. The vesicles contain a clear yellowish liquid, which gradually becomes puriform; those that appear last rarely reach full development. They show no tendency to rupture, are distended, subsequently becoming slightly umbilicated, and by the end of two weeks have gradually dried to thin yellowish or brownish crusts, which soon drop off. Except in severe cases, especially the hemorrhagic form, scarring rarely results. A tendency to group is characteristic of the eruption. The disease is acute, and runs its course usually in from ten to twenty days.
In some instances the lesions run an abortive course, barely arriving at the point of vesiculation. On the other hand, small blebs and pustules may be formed. In severe cases the vesicles may become hemorrhagic. The neuralgic pain may accompany the disease, and in severe cases, especially in persons advanced in years, may persist long after the eruption has subsided. In some cases burning is the only subjective symptom complained of. The disease is not confined to any age or sex. It is more common in the winter season. As a rule, it is limited to one side of the body. Moreover, it is rarely seen in the same individual twice. The intercostal and lumbar regions show the eruption most frequently. In zoster of the orbital region the eye becomes involved, and the disease may in some instances terminate in loss of sight, and even in destruction of the eyeball. Any nerve-tract or part of the body may be the seat of the eruption, hence the names zoster capitis, facialis, brachialis, pectoralis, etc. The disease is not uncommon.
The eruption is dependent upon an irritable and inflamed state of the ganglia or nerves—a neuritis. Hence any agent that may bring about this condition is capable of producing the eruption. Among such may be included atmospheric changes, sudden checking of the perspiration, compression, nerve-injuries, operations, and similar influences. In some instances the eruption is noted to follow the administration of arsenic. The primary seat of the affection is usually in the spinal ganglia; they are found softened and altered in structure and the nerves inflamed and thickened. It may, however, have its beginning along the tract of a nerve or in the peripheral branches. In fact, it may be spinal, ganglionic, or peripheral in origin. The vesicles are found to have their seat in the lower strata of the rete. The surrounding corium and papillæ show more or less round-cell infiltration, with dilatation of the papillary blood-vessels. A perineuritis, with cell-infiltration in and about the neurilemma, is also usually observed. The vesicles contain rete-cells, pus-corpuscles, and serum.
The diagnosis is usually unattended with difficulty. The premonitory pain, the appearance of grouped vesicles upon inflammatory bases, with no tendency to rupture, and the limitation of the eruption to one side of the body, are sufficiently characteristic. The vesicles are larger than those of eczema, and lack the well-known tendency of the latter to break and discharge a gummy fluid which rapidly forms to crusts. In erysipelas the line of demarcation, the deep-reddish color, and the constitutional symptoms will serve to differentiate the diseases. It is to be distinguished from simple herpes by its location, number of groups, unilateral distribution, and absence of relapses. The prognosis is favorable, as the eruption usually disappears at the end of two or three weeks; severe cases, however, may last a month or more. When involving the eye, the possibility of its destroying the same, and even of a fatal result, is to be kept in mind. In elderly subjects the neuralgic symptoms are apt to prove persistent.
Treatment is mainly expectant. The disease is self-limited, and hence severe measures are to be avoided. Internal treatment has, so far as experience shows, very little influence upon its course. Phosphide of zinc, in one-third grain doses every three hours, at times seems to have a beneficial effect. Morphia, hypodermically or by the mouth, is required if the neuralgia is severe. The galvanic current, applied once or twice daily, will sometimes quiet the pain and favorably influence the course of the disease. Locally, the parts are to be protected from irritation. For this purpose dusting-powders, to which a small quantity of morphia and camphor may be added, may be employed. The parts should be further protected with a bandage. Oxide-of-zinc ointment, and anodyne ointments containing powdered opium or belladonna, may also be used. Painting the efflorescence with oil of peppermint or with solutions of menthol, thymol, or carbolic acid will be found to relieve the burning and pain; so also, flexible collodion, containing ten grains of morphia to the ounce, will sometimes afford relief. The parts subsequently may be covered with a layer of cotton batting.
Dermatitis Herpetiformis.