PRURIGO (CHRONIC ITCHING)

Prurigo is a chronic, itching, papular Skin disease which has a predilection for the lower abdomen, buttocks, and extensor surfaces of the limbs. Some lesions in addition are likely to occur on the trunk, scalp, forehead, face, and neck. Prurigo begins mostly in children from 2 to 5 years of age, being more common in boys. Probably in time all cases of prurigo will be proven to be severe types of papular urticaria caused by insect bites in hypersensitive children.

There are two forms of prurigo; namely, prurigo mitis, the more com­mon, which is comparatively mild; and prurigo agria or ferox, which is severe though exceedingly rare in this country.

Prurigo is a chronic, itching, papular Skin disease

Prurigo mitis usually begins as papular urticaria and, persistently re­curring, gradually assumes the characteristics of prurigo and lasts indefi­nitely. Prurigo mitis, therefore, can only be distinguished from papular urticaria after the second year of the disease by the uniform type of its primary lesion (the prurigo papule), by the chronicity, severity, scars, Iichenification, and cczematization. The prurigo papules at first are easier to palpate than to see, but later become small, rounded, extremely pruritic, flesh-colored or reddish elevations. The lesions are symmetrically distributed and may be few in number or very profuse. As time progresses the urticarial element is less noticeable but the extreme pruritus persists and leads to even greater secondary changes. The excoriations, lichenifica-tion, and eczematization become more and more pronounced and are ac­companied by enlarged glands and associated constitutional symptoms.

In prurigo agria the hard, excoriated prurigo papules and lichenification are completely predominant, the urticarial elements being sparse or ab­sent. Incessant scratching causes pitted scars and pustulation. The adenop­athy is not pronounced in the groins and axillae, which are free from skin lesions. There is often the history of excessive ingestion of carbohydrates, sweets and raw fruits. The hair is lusterless. Examination of the blood shows eosinophilia. There is usually an allergic family history, and skin tests reveal multiple sensitizations but these have no direct bearing on the etiology or therapy.

Treatment. Treatment includes the development of a hygienic regimen, consisting of liberal and proper diet with green vegetables, meat and cereals but no egg, chocolate, candy or citrus fruit. The addition of cal­ciferol may be indicated. Small doses of phenobarbital have value. Treatment should be given for fleas as advised on pages 166 and 441, or for intestinal parasites if present.

Antihistamine creams and hydrocortisone ointment are beneficial. The combination of tar, sulfur, and green soap, known as Wilkinson's salve, has special value in this condition, being applied in either quarter or half strength. The following formula is beneficial:

R    Prep, chalk..................................................................................      1.0

Beechwood tar...........................................................................      1.5

Sulfur ppt...................................................................................      1.5

Green soap ................................................................................    13.0

Lard...........................................................................................    13.0

M. and S. Apply locally morning and night.