The congestion of the external genitals that accompanies pregnancy may also produce pruritus.
There are some cases of pruritus vulvæ, however, in which no physical cause for the intolerable itching can be discovered, and in which minute examination of the affected portions of skin or mucous membrane demonstrates no pathological change. Such cases are called idiopathic.
The itching may be so severe that the woman cannot refrain from scratching and rubbing the parts on all occasions. She becomes debarred from the society of her friends, and seeks relief in anodynes and hypnotics. The continual scratching increases the irritation of the vulva, and an eczematous eruption may result, which produces an irritating discharge that spreads the irritation to other parts of the body with which it may come in contact.
The itching of pruritus may extend into the vagina, to the skin of the abdomen, to the inner aspect of the thighs, and to the anus.
In the treatment of pruritus it is first of importance to discover, if possible, the cause of the itching. Any vaginal or uterine discharge should be investigated. Discharge from the uterus can be eliminated as a cause by placing against the external os a pledget of cotton, frequently renewed, to absorb the discharge before it reaches the vulva, or the parts may be kept clean by frequent douches. In children the stools should be examined for the thread-worm. The urine should always be examined. Diabetes is a frequent cause of pruritus vulvæ in old women. Any pathological condition of the uterus, Fallopian tubes, and ovaries should be treated before we can eliminate this as a possible cause of pruritus.
In the cases of so-called idiopathic pruritus in which no local lesion can be discovered attention should be directed to the general nutrition of the patient. As in pruritus ani, the gouty diathesis may cause the disease. Alcoholic drinks, rich food, fish and shell-fish, may assist in its production.
Treatment.—A great variety of local applications have been used for the relief of pruritus. In case of diabetes the urine should, as much as possible, be kept from contact with the parts, which should be thoroughly dried after urinating, and dusted with a powder consisting of equal parts of subnitrate of bismuth and prepared chalk.
The following local applications are useful in pruritus:
| Bichloride of mercury, | gr. ½; | ||
| Emulsion of bitter almonds, | ℥j, | ||
| applied twice a day. | |||
A powder of 1 grain of morphine to 2 grains of prepared chalk, applied twice a day.