American Medical Association Family Medical Guide - American Medical Association [759]
Rosacea
Rosacea is a skin disorder in which the tiny blood vessels in the face (usually in the cheeks, nose, and forehead; see page 123) enlarge over weeks or months. The cause is unknown, but the following factors may play a role—genetic predisposition, environmental factors, a disorder of the immune system or blood vessels, tiny mites that live in hair follicles, or Helicobacter pylori (a bacterium that causes infection in the gastrointestinal system). The condition can be triggered by hot or caffeine-containing foods or beverages, alcohol, sun exposure, stress, exercise, cold wind, or hot baths or showers. Women are more often affected, but the disorder is often more severe in men.
Symptoms and Diagnosis
In rosacea, the entire face may be red, or it may be red only in streaks or patches. The skin affected by rosacea can have pus-filled bumps or pimples. In some cases, the nose is enlarged and bulbous, and thick, knobby bumps may develop on the nose (a condition called rhinophyma). Half of people who have rosacea also develop a form of the eye infection conjunctivitis (see page 1038). A doctor can diagnose rosacea by its appearance.
Treatment
Because rosacea cannot be cured, your doctor may refer you to a dermatologist (a doctor who specializes in disorders of the skin) to treat your symptoms and improve your appearance. He or she will prescribe topical or oral antibiotics such as clindamycin, tetracycline, doxycycline, erythromycin, or metronidazole. Sulfacetamide may be prescribed to treat conjunctivitis. Redness, enlarged blood vessels, and rhinophyma can be treated with laser surgery (see page 1088) or pulsed light therapy (which uses high-intensity pulses of light) to penetrate the skin and correct skin imperfections.
Hives
Hives are red, itchy lumps that develop on the skin, usually as a result of a mild allergic reaction (see page 912). They sometimes have a pale center and may join together to form large, irregular patches (see page 122). Hives are common and can appear anywhere on the body, brought on by factors such as an allergic reaction to foods or food additives, medications, plants, heat, cold, or sunlight.
In many cases, it is impossible to pinpoint the cause of hives. In rare cases, hives may be a symptom of a life-threatening disorder such as a severe allergic reaction or lupus (see page 920). In some people, stress, taking aspirin, or consuming caffeine can worsen hives.
In most cases, hives clear up on their own within a few hours. You will probably be able to identify and avoid the source of the problem if it is a particular food, plant, or medication. A food dye that is added to a wide variety of foods may be more difficult to identify and avoid. See your doctor or an allergist for skin tests (see page 912) to help identify the cause. He or she may prescribe an antihistamine to control your symptoms. Occasionally, hives persist or recur after treatment.
WARNING!
Hives May Be a Life-Threatening Allergic Reaction
If, soon after you develop hives, the tissues under the hives start to swell, especially on your face and around your lips or eyes, call 911 or your local emergency number or go to the nearest hospital emergency department immediately. You may be having a severe allergic reaction (anaphylactic shock; see page 915).
Impetigo
Impetigo is a highly contagious bacterial skin infection that is especially common in children. In infants, it can spread and infect the entire body. The bacteria (usually staphylococcus or streptococcus) enter through breaks in the skin such as cuts or scratches. In rare cases, if impetigo is caused by streptococcal bacteria and is not treated, a life-threatening condition called glomerulonephritis (see page 807) may develop.
Symptoms and Diagnosis
In impetigo, a small patch