skin disorders
Treatment of Skin Disorders
Topical Preparations
The active ingredient, or drug, in a topical preparation is mixed with an inactive ingredient (called the vehicle). The vehicle determines the consistency of the product (for example, thick and greasy or light and watery) and whether the active ingredient remains on the surface or penetrates the skin. Depending on the vehicle used, the same drug can be placed in Ointments Creams Lotions Baths and soaks Foams Solutions Powders Gels In addition, many preparations are available in different strengths (concentrations). Choice of vehicle depends on where the drug will be applied, how it will look, and how convenient it is to apply and leave on. (such as petroleum jelly) are oily and contain very little water. They can be messy, greasy, and difficult to wash off. Ointments are most appropriate when the skin needs lubrication or moisture. Ointments are usually better than creams at delivering active ingredients into the skin. A given concentration of a drug is more potent in an ointment than in a cream. Ointments are less irritating than creams and much less irritating than gels, lotions, and solutions for open wounds such as Types of Skin Marks and Growths or Creams,the most commonly used preparations, are emulsions of oil in water, meaning they are primarily water with an oil component. (An ointment is the opposite, some water mixed mostly with oil.) Creams are easy to apply and appear to vanish when rubbed into the skin. They are relatively nonirritating. are similar to creams but contain more water. They are actually suspensions of finely dispersed, powdered material in a base of water or oil and water. They are less effective than ointments, creams, and gels at delivering drugs and are considered of lower potency for a given drug concentration. However, lotions have a number of beneficial effects. They are easy to apply to hairy skin and they are particularly useful for cooling or drying inflamed or oozing lesions, such as those caused by Contact Dermatitis , are used when treatment must be applied to large areas of the body. This technique is often used in the form of sitz baths for over-the-counter (OTC) treatments of mild skin problems such as Hemorrhoids . Baths are not often used to apply potent prescription drugs because of difficulties controlling the amount of drug delivered. Foamsare aerosol preparations (liquids stored under pressure with a propellant so that the mixture can be dispensed) that use a base of alcohol or something soothing to the skin (called an emollient). They are rapidly absorbed into the skin and are often used in hair-covered areas of the body. , and plain water. Solutions are convenient to apply, especially for scalp disorders such as Psoriasis or Powdersare dried forms of substances that are used to protect areas where skin rubs against skin—for instance, between the toes or buttocks, in the armpits or groin, or under the breasts. Powders are used on skin that has been softened and damaged by moisture (macerated). They may be mixed with active drugs such as antifungal drugs. are water-based or alcohol-based substances thickened without oil or fat. The skin does not absorb gels as well as it absorbs preparations containing oil or fat. Thus, they are often most effective for conditions that require slow absorption, such as Acne , If doctors need to increase the effect of a topical drug, they prescribe an ointment rather than a cream. 