If asked to write down the organs in the human body, not many people would list the skin, but it is in fact the largest organ of the body and has many important functions. The skin protects your body from injury, controls your body’s temperature, and holds water in your body so you do not shrivel up like a prune. When you’re hot, your skin perspires to cool you off. The fat layers of your skin help keep in warmth when it is cold outside. Without the protection of the skin, no one would be able to survive.
Just like other organs, the skin can have many different types of problems, from simple rashes to severe acne or psoriasis. And just like other organs, there are many different types of drugs that can be used to treat these problems.
Some of the first skin preparations that come to mind are ointments, lotions, and creams. These are very important forms of drug delivery to the skin. Ointments are oily or greasy preparations of drugs. Some drugs do not dissolve very well in water, but can be dissolved in oil. These drugs have to be given as an ointment. The greasiness helps protect skin from further physical damage, and also improves the penetration of the drug into the skin. This often makes ointments more potent than the cream or lotion forms of the drug.
Creams and lotions, on the other hand, are less oily. They tend to vanish easily when rubbed onto the skin. The major difference between lotions and creams is their thickness. Lotions are thinner and work into the skin much faster than creams.
Relief for Itches
Many different drugs are available as ointments, creams, or lotions. One common family of these drugs are steroids, although they should not be confused with the potentially harmful steroids taken illegally by people interested in building up muscles. Instead, steroidal skin drugs help reduce irritation, itching, and inflammation. Hydrocortisone, the most common of these steroids, can be purchased over the counter in low strengths in creams and lotions. The more potent forms are available only by prescription.
Steroids can be used to treat many different skin diseases. Psoriasis, a disease in which the skin develops silver scaly patches, usually on the elbows, knees, and scalp, can be treated by using very potent topical steroids. Severe forms of psoriasis can affect the whole body. Ointments and creams are used on the elbows and knees, and lotions are used on the scalp. Psoriasis is also treated using ointments made with coal tar, which helps reduce the thickness of the scaly patches. Ultraviolet light also helps control psoriasis.
Topical steroids are also commonly used to treat simple rashes, poison ivy, and dermatitis (an inflammation of the skin that comes from touching things that you may be allergic or sensitive to). It is important, however, to find out exactly what is causing the symptoms so that the source of the problem can be eliminated.
Safer in the Sun
Another common use of creams and lotions is in sunscreens. Sunscreens come in different forms, but all of them function in much the same way. The active ingredients are absorbed into the skin and take up the sun’s ultraviolet energy to protect the skin from being burned. Sunscreens need to be applied 30 to 60 minutes before going out in the sun so they can be absorbed into the skin and do their job. The potency of the sunscreen is identified by the sun protection factor (SPF). This is the number that appears on the bottle or tube of sunscreen. The higher the number, the greater the protection from a sunburn.
Help for Acne
Acne is a common skin problem that is treated using topical drugs. Acne, which can occur in adolescents and adults as well, typically affects the skin on the face, chest, and back. Acne results when a hair follicle becomes plugged with sebum (an oily, waxy substance secreted by the sebaceous glands in the skin), dead cells, and possibly bacteria. This produces closed comedones (whiteheads) and open comedones (blackheads). Severe forms have pustules that are very sensitive and painful and may lead to scarring.
Probably the most common topical drug for acne is benzoyl peroxide. Benzoyl peroxide, a drug that dries the skin, can be found as a lotion or cream in many over-the-counter acne products. As the skin dries, the pores open and the sebum flows out more easily, which prevents the formation of a comedone.
Severe forms of acne usually require more aggressive treatment to prevent scarring of the skin. Topical antibiotics such as tetracycline, clindamycin, or erythromycin can be used to prevent bacteria from infecting the comedone. Tetracycline can also be taken as capsules for acne treatment. Isotretinoin (Accutane), a relatively new acne drug, is used for treating severe pustular acne. This drug is given orally, and is available only by prescription. It reduces the amount of sebum that is produced by the skin, causes the skin to dry, and prevents the formation of comedones.
Taming Fungal Infections
Another major group of drugs that can be used on the skin are antibiotics and antifungals. Topical antibiotics and antifungals are found as ointments, creams, lotions, sprays, and powders. The topical antibiotics are used to treat wounds, by curing or preventing infection from bacteria. These are often used in combination with a protective bandage to keep the wound clean. These products can contain combinations of the drugs bacitracin, gramicidin, neomycin, or polymyxin.
Topical antifungal drugs are commonly used to treat skin infections that affect the feet (athlete’s foot, for example) or the groin area. These can be caused by many different types of fungi. Fungi typically like to live in warm, moist areas, which is why the feet and groin are common sites of infection. These infections cause the skin to be irritated, red, and itchy, and it may even become scaly. There are a variety of antifungal drugs that can be used for these infections, including tongue twisters like clotrimazole, miconazole, undecylenic acid, tolnaftate, and haloprogin.
The very fact that the skin is the largest organ of the body is probably why it can have many different problems. Fortunately, today we have so many different drugs to treat it.