Herpes zoster
Diagnosis
In the ordinary ease this is easy. The diagnosis from herpes simplex on the face has been considered on .Difficulties are most likely to arise in cases which are seen before the vesicles have appeared, when there is only pain or a painful red patch. If the possibility of zoster is borne in mind the position of the patch or pain in the distribution of a cutaneous nerve on one side of the body only, will probably lead to a correct diagnosis.
Treatment
There is no specific treatment. protection of the vesicles from trauma and infection, and relief of pain, are the requirements. If seen in the stage before the appearance of the vesicles, or while the latter are still small, the area may be painted with collodion. If the vesicles are already large or have ruptured, local antibiotics are the best application, since they control secondary infection and so reduce residual scarring. The pain may require aspirin, phenacetin, etc, by the mouth, or even injections of morphia, while radiant heat and ultra-violet light locally are often helpful. Intramuscular injections of vitamin B12(cyanocobalamin) in dailv doses of 1000 micrograns for 7-10 days, are said to shorten the course of the disease and decrease the chances of subsequent neuralgia. For the treatment of neuralgia following zoster, X-rays are useful in some cases either superficial, to the affected skin, or deep, to the appropriate ganglia. Radiant heat is also helpful.