Penicillin allergy

Penicillin allergy is an overreaction by your immune system to penicillin and related antibiotics. If you have a penicillin allergy, your reaction to taking the antibiotic may range from a rash to anaphylaxis, a potentially life-threatening condition.

Penicillin antibiotics are widely prescribed for bacterial infections, such as strep throat. However, not all unfavorable reactions to penicillin are a true penicillin allergy.

It isn't clear why some people develop penicillin allergy. Once you've had an allergic reaction to penicillin, the simplest way to prevent penicillin allergy is to avoid penicillin and related antibiotics.

Peanut allergy

Peanut allergy is common, especially in children. Peanut allergy symptoms can range from a minor irritation to a life-threatening reaction (anaphylaxis). For some people with peanut allergy, even tiny amounts of peanuts can cause a serious reaction.

If you or your child has had a reaction to peanuts, tell your doctor about it. Peanut allergy is one of the most common causes of severe allergy attacks.

It's important to get even a minor reaction to peanuts checked out. Even if you or your child has had only a mild allergic reaction in the past, there's still a risk of a more serious future reaction.

Nickel allergy

Nickel allergy is one of the most common causes of allergic contact dermatitis — an itchy rash that appears when your skin touches a usually harmless substance.

Nickel allergy is commonly associated with earrings and other jewelry, particularly jewelry associated with body piercings. But nickel can be found in many everyday items — from coins to zippers, from cellphones to eyeglass frames.

Nickel allergy can affect people of all ages. A nickel allergy usually develops after repeated or prolonged exposure to items containing nickel. Treatments can reduce the symptoms of nickel allergy. Once you develop nickel allergy, however, you will always be sensitive to the metal and need to avoid contact.

Nickel allergy

Nickel allergy is one of the most common causes of allergic contact dermatitis — an itchy rash that appears when your skin touches a usually harmless substance.

Nickel allergy is commonly associated with earrings and other jewelry, particularly jewelry associated with body piercings. But nickel can be found in many everyday items — from coins to zippers, from cellphones to eyeglass frames.

Nickel allergy can affect people of all ages. A nickel allergy usually develops after repeated or prolonged exposure to items containing nickel. Treatments can reduce the symptoms of nickel allergy. Once you develop nickel allergy, however, you will always be sensitive to the metal and need to avoid contact.

Mold allergy

If you have a mold allergy, your immune system overreacts when you breathe in mold spores. This triggers a cascade of reactions that lead to allergic symptoms. Like other allergies, a mold allergy can make you cough, make your eyes itch and cause other symptoms that make you miserable. In some people, mold allergy is linked to asthma and exposure causes restricted breathing and other airway symptoms.

If you have a mold allergy, the best defense is to reduce your exposure to the types of mold that cause your reaction. While it isn't always possible to avoid mold allergy triggers, medications can help keep mold allergy reactions under control.

Milk allergy

Milk allergy is an abnormal response by the body's immune system to milk and products containing milk. Cow's milk is the usual cause of milk allergy, but milk from sheep, goats and buffalo also can cause a reaction. Some children who are allergic to cow's milk are allergic to soy milk, too. Milk allergy is one of the most common food allergies in children.

A milk allergy usually occurs minutes to hours after consuming milk. Signs and symptoms of milk allergy range from mild to severe and can include wheezing, vomiting, hives and digestive problems. Rarely, milk allergy can cause anaphylaxis — a severe, life-threatening reaction.

Avoidance is the primary treatment for milk allergy. Fortunately, most children outgrow a milk allergy by age 3.

Latex allergy

Latex allergy is a reaction to certain proteins found in natural rubber latex, a product manufactured from a milky fluid that comes from the rubber tree. If you have a latex allergy, your body mistakes latex for a harmful substance.

Latex allergy may cause allergic reactions ranging from sneezing or a runny nose to anaphylaxis, a potentially life-threatening condition. Your doctor may determine if you have a latex allergy or if you're at risk of developing a latex allergy.

Understanding latex allergy and becoming familiar with common sources of latex can help you prevent your own allergic reactions or those of someone else.

Food allergy

Food allergy is an immune system reaction that occurs soon after eating a certain food. Even a tiny amount of the allergy-causing food can trigger signs and symptoms such as digestive problems, hives or swollen airways. In some people, a food allergy can cause severe symptoms or even a life-threatening reaction known as anaphylaxis.

Food allergy affects an estimated 6 to 8 percent of children under age 5, and about 3 to 4 percent of adults. While there's no cure, some children outgrow their food allergy as they get older. It's easy to confuse a food allergy with a much more common reaction known as food intolerance. While bothersome, food intolerance is a less serious condition that does not involve the immune system.

Egg allergy

Eggs are one of the most common allergy-causing foods in children.

Egg allergy symptoms usually occur a few minutes to a few hours after eating eggs or foods containing eggs. Signs and symptoms range from mild to severe and can include skin rashes, hives, nasal inflammation, and vomiting or other digestive problems. Rarely, egg allergy can cause anaphylaxis — a life-threatening reaction.

Egg allergy can occur as early as infancy. Most children outgrow their egg allergy before adolescence. But in some cases, it continues into adulthood.

Dust mite allergy

Dust mite allergy is an allergic reaction to tiny bugs that commonly live in house dust. Signs of dust mite allergy include those common to hay fever, such as sneezing and runny nose. Many people with dust mite allergy also experience signs of asthma, such as wheezing and difficulty breathing.

Dust mites, relatives of the spider, are too small to see without a microscope. Dust mites eat skin cells shed by people, and they thrive in warm, humid environments. In most homes, bedding, upholstered furniture and carpeting provide an ideal environment for dust mites.

Steps to reduce the number of dust mites in your home can often control dust mite allergy. Medications or other treatments may be necessary to relieve symptoms and manage asthma.

Allergies

Allergies occur when your immune system reacts to a foreign substance such as pollen, bee venom or pet dander.

Your immune system produces substances known as antibodies. Some of these antibodies protect you from unwanted invaders that could make you sick or cause an infection. When you have allergies, your immune system makes antibodies that identify a particular allergen as something harmful, even though it isn't. When you come into contact with the allergen, your immune system's reaction can inflame your skin, sinuses, airways or digestive system.

The severity of allergies varies from person to person and can range from minor irritation to anaphylaxis — a potentially life-threatening emergency. While most allergies can't be cured, a number of treatments can help relieve your allergy symptoms.

Primary aldosteronism

Primary aldosteronism (al-DOS-tuh-ro-niz-um) is a type of hormonal disorder that leads to high blood pressure. Your adrenal glands produce a number of essential hormones. One of these is aldosterone, which balances sodium and potassium in your blood. In primary aldosteronism, your adrenal glands produce too much aldosterone, causing you to lose potassium and retain sodium. The excess sodium in turn holds onto water, increasing your blood volume and blood pressure.

Diagnosis and treatment of primary aldosteronism are important because people with this form of high blood pressure have a higher risk of heart disease and stroke. Also, the high blood pressure associated with primary aldosteronism may be curable. Options for people with primary aldosteronism include medications, lifestyle modifications and surgery.

Airplane ear

Airplane ear is the stress exerted on your eardrum and other middle ear tissues when the air pressure in your middle ear and the air pressure in the environment are out of balance. You may experience airplane ear at the beginning of a flight when the airplane is climbing or at the end of a flight when the airplane is descending. These fast changes in altitude cause air pressure changes and can trigger airplane ear.

Airplane ear is also called ear barotrauma, barotitis media or aerotitis media.

Usually self-care steps — such as yawning, swallowing or chewing gum — can prevent or correct the differences in air pressure and improve airplane ear symptoms. However, a severe case of airplane ear may need to be treated by a doctor.

Age spots (liver spots)

Age spots — also called liver spots and solar lentigines — are flat gray, brown or black spots. They vary in size and usually appear on the face, hands, shoulders and arms — areas most exposed to the sun. Though age spots are very common in adults older than age 40, they can affect younger people as well.

True age spots are harmless and don't need treatment, but they can look like cancerous growths. For cosmetic reasons, age spots can be lightened with skin-bleaching products or removed. However, preventing age spots — by avoiding the sun and using sunscreen — may be the easiest way to maintain your skin's youthful appearance and to avoid these dark skin spots.

Attention-deficit/hyperactivity disorder (ADHD) in children

Attention-deficit/hyperactivity disorder (ADHD) is a chronic condition that affects millions of children and often persists into adulthood. ADHD includes a combination of problems, such as difficulty sustaining attention, hyperactivity and impulsive behavior.

Children with ADHD also may struggle with low self-esteem, troubled relationships and poor performance in school. Symptoms sometimes lessen with age. However, some people never completely outgrow their ADHD symptoms. But they can learn strategies to be successful.

While treatment won't cure ADHD, it can help a great deal with symptoms. Treatment typically involves medications and behavioral interventions. Early diagnosis and treatment can make a big difference in outcome.

Mesenteric lymphadenitis

Lymphadenitis is a condition in which your lymph nodes — tissues that help your body fight off illness — become inflamed. Mesenteric lymphadenitis (mez-un-TER-ik lim-fad-uh-NIE-tis) is an inflammation of the lymph nodes in the membrane that attaches your intestine, or bowel, to your abdominal wall (mesentery). Mesenteric lymphadenitis usually results from an intestinal infection.

There are about 26 feet of bowel in your abdominal cavity. The bowel is the only organ in your body that "is free to move about its cavity," but the mesentery limits that movement. If not for the mesentery, the bowel likely would twist upon itself, causing obstruction.

Mesenteric lymphadenitis occurs mainly in children and teens and often mimics the signs and symptoms of appendicitis. Unlike appendicitis, however, mesenteric lymphadenitis is seldom serious and clears on its own

Addison's disease

Addison's disease is a disorder that occurs when your body produces insufficient amounts of certain hormones produced by your adrenal glands. In Addison's disease, your adrenal glands produce too little cortisol and often insufficient levels of aldosterone as well.

Also called adrenal insufficiency, Addison's disease occurs in all age groups and affects both sexes. Addison's disease can be life-threatening.

Treatment for Addison's disease involves taking hormones to replace the insufficient amounts being made by your adrenal glands, in order to mimic the beneficial effects produced by your naturally made hormones.

Nicotine dependence

Nicotine dependence is an addiction to tobacco products caused by the drug nicotine. Nicotine dependence — also referred to as tobacco dependence — means you can't stop using the substance, even though it's causing you harm. While it's the nicotine in tobacco that causes nicotine dependence, the toxic effects come mainly from other substances in tobacco. Smokers have much higher rates of heart disease, stroke and cancer than do nonsmokers.

Nicotine produces physical and mood-altering effects in your brain that are temporarily pleasing. These effects make you want to use tobacco and lead to dependence. At the same time, stopping tobacco use causes withdrawal symptoms, including irritability and anxiety.

Many effective treatments for nicotine dependence are available to help you manage withdrawal and stop smoking for good. Ask your doctor for help.

Compulsive gambling

Compulsive gambling is the uncontrollable urge to keep gambling despite the toll it takes on your life. If you're prone to compulsive gambling, you may continually chase bets, lie or hide your behavior, and resort to theft or fraud to support your addiction.

Compulsive gambling is a serious condition that can destroy lives. Although treating compulsive gambling can be challenging, many compulsive gamblers have found help through professional treatment.

Drug addiction

Drug addiction is a dependence on an illegal drug or a medication. When you're addicted, you may not be able to control your drug use and you may continue using the drug despite the harm it causes. Drug addiction can cause an intense craving for the drug. You may want to quit, but most people find they can't do it on their own.

For many people, what starts as casual use leads to drug addiction. Drug addiction can cause serious, long-term consequences, including problems with physical and mental health, relationships, employment and the law.

You may need help from your doctor, family, friends, support groups or an organized treatment program to overcome your drug addiction and stay drug-free.