Dear Doctor: Can you talk about overweight kids and fatty liver disease? I thought this was something that only happens to alcoholics.

Dear Reader: While excessive alcohol consumption is certainly one path to a diagnosis of fatty liver disease, the condition can affect drinkers and non-drinkers alike -- raising the risk of heart disease and potentially causing subsequent problems that can lead to liver cancer. New research suggests that children who are overweight as toddlers may go on to develop the metabolic markers of fatty liver disease several years later.

Fatty liver disease is pretty much what it sounds like -- a damaging buildup of fat in the tissues of the liver. One path to that buildup is through the heavy use of alcohol, but what we're talking about here is non-alcoholic fatty liver disease, or NAFLD. This occurs when factors other than alcohol cause fat to accumulate in the liver. The presence of the fat triggers an inflammatory response that, over time, leads to liver damage.

The condition is most common among individuals who are obese or overweight, have diabetes or pre-diabetes, have high blood levels of cholesterol or triglycerides, and have high blood pressure. It's associated with metabolic syndrome, and also with certain cancer drugs, corticosteroids and hepatitis C. Research suggests there may be a genetic component as well. And although NAFLD is most common among individuals in their 40s and 50s, emerging data shows that children can be affected.

The liver, which is the largest internal organ, has a daunting to-do list. It converts food into fuel, stores that fuel and makes it available as needed, clears toxins from the blood and renders them harmless, makes proteins that help blood to clot, breaks down fats, helps manage blood sugar levels, and stores and releases various minerals and vitamins. And that's just scratching the surface. Bottom line, the liver's numerous metabolic functions mean that for you to stay healthy, your liver needs to be healthy as well.

In fatty liver disease, the presence of fat causes inflammation, which can lead to scarring and damage to the complex structures of the liver that can be irreversible. At its most extreme, NAFLD can lead to cirrhosis of the liver and even death. It's estimated that 80 million people in the United States -- that's one-quarter of the U.S. population -- have some degree of fatty liver disease. Close to 60 percent of them are men.

While NAFLD has no obvious symptoms, abdominal pain, chronic fatigue, nausea, loss of appetite and elevated liver enzymes may be indicators of the condition in individuals who exhibit the appropriate risk factors. Although at this time there are no specific treatments for the condition, lifestyle changes can have a beneficial effect.

Reaching and maintaining a healthy weight is considered the leading preventative. Several studies have shown a direct correlation between increased sugar consumption and certain metabolic changes that stress the liver. Soft drinks in particular have been shown to increase the markers of fatty liver disease. So ditch the sweets, sodas and processed foods. Focus instead on fresh fruits and vegetables, leafy greens, healthful fats and lean proteins. Your liver -- and your whole body -- will thank you.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: What can you tell me about lupus? Is it true that there are two different kinds? One of the skin, and one that affects the entire body?

Dear Reader: There are actually several types of lupus-related skin conditions. While some of these can affect the skin alone, many are related to systemic lupus erythematosus (SLE). This is the most common type of lupus and can affect the skin and any organ in the body. First recognized in the 19th century, SLE was initially thought to be a skin disorder because of its obvious external effects. It took many more years for physicians to realize that it was actually a systemic autoimmune disease with the ability to affect any organ in the body.

In the United States, estimated prevalence of the disease varies, but is generally regarded as slightly more than 1 in 1,000 people. In adults, lupus occurs more frequently in women than in men, with a female-to-male ratio of about 8-to-1. In the United States, it's more common among people of African, Asian and Hispanic ancestry, with African-Americans having nearly 2 1/2 times the likelihood of lupus compared to those of European ancestry.

Genetics are a significant risk factor for the disease. In a study among Latinos, if one sibling had SLE, the other sibling had a 29 times greater risk of developing lupus compared to the rest of the population. Certain medications also can increase the risk of lupus.

Lupus develops when the immune system's antibodies attack cell structures -- the nuclei and membranes -- and form immune complexes that circulate and deposit in different portions of the body. These immune complexes, made of antibodies attached to antigens, bring in white blood cells that release inflammatory chemicals, which damage the tissues further.

The disease is marked by cycles of flares and remissions. When the disease is flaring, or active, a person suffers from fatigue, muscle aches, joint pain and sometimes fever. He or she also may lose a considerable amount of weight.

Lupus affects the kidneys 50 percent of the time, which can lead to kidney dysfunction, and the gastrointestinal system 40 percent of the time, which can include the esophagus, the small or large intestine, the pancreas and the liver. Joint pain and arthritis are also common, and although lupus can affect any joint, the knees, wrists and fingers are most susceptible.

Lupus can also damage the heart and lungs, and the deposits of immune complexes can cause inflammation of blood vessels. In short, any part of the body can be affected, including the brain, eyes, blood cells, muscles, bone and skin.

People with systemic lupus most typically develop a type of rash that affects the face at the cheeks and nose, described as a "butterfly" rash. The rash is often exacerbated by sun exposure, and this may be the first sign of lupus, occurring months or years before other symptoms.

Some types of lupus-related skin conditions are not associated with systemic lupus. These lesions, commonly diagnosed with a biopsy, are often circular and plaquelike and can be located anywhere upon the body.

Treatment for these skin conditions includes non-steroidal immune-modulating creams and possibly immunosuppressant oral drugs; stronger immunosuppressant drugs are necessary for systemic lupus erythematosus.

With all types of lupus, treatment is focused on controlling symptoms. With SLE specifically, it will be a lifelong commitment.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: What on earth is bee-sting therapy -- and what is it supposed to do? I ask because apparently someone died after having it.

Dear Reader: Using bee products like honey, pollen, royal jelly and venom to treat illness and promote healing is a practice known as apitherapy. The word comes from apis, which is the genus the honeybee belongs to. References to apitherapy date back to ancient Egypt, Greece and China. Hippocrates is said to have used bee venom to ease the pain of arthritis, which is one of the primary targets of modern-day treatment. The theory is that the bee sting causes the immune system to mount an anti-inflammatory response that is beneficial to the patient. However, that same immune response can become deadly.

That's the case with a woman in Spain who had been undergoing monthly treatments in which she was stung by live bees to address muscle issues and stress. She had no adverse reactions for two years, but in that final session she developed "wheezing, dyspnea, and sudden loss of consciousness immediately after a live bee sting," according the Journal of Investigational Allergology and Clinical Immunology. Although the private clinic treated her with corticosteroids, which counter inflammation, they didn't have any epinephrine, which is used to reverse extremely low blood pressure, wheezing, hives and other symptoms of a severe allergic reaction. An ambulance reportedly took 30 minutes to arrive, and despite medical treatment at a hospital, the woman later died.

The report about the incident, which took place in 2015, was published earlier this year. But because bee sting therapy currently has a few high-profile celebrity proponents, the story has received quite a bit of attention. According to the analysis of the case, this was the first reported death due to bee venom therapy. The authors point out that although a patient may initially tolerate the venom, a hypersensitivity reaction is still possible. In fact, repeated exposure can lead to a higher risk of sensitization.

Bee venom, also known as apitoxin, is a complex mix of proteins, peptides and bioactive agents. The main ingredient is melittin, a small protein that disrupts the membranes of red blood vessels at the site of the sting, causing them to burst. Blood vessels expand in the presence of melittin, which can cause a swift drop in blood pressure. Add the presence of a second protein that causes burning pain, and histamines for itching and swelling, and a drop of bee venom delivers a world of hurt.

But it's that complex chemistry of the venom that has captured the imagination of healers for millennia. Melittin turns out to be a powerful anti-inflammatory agent. Injections of bee venom have been used successfully to fight inflammation in patients with arthritis and multiple sclerosis. In recent research, certain cancers appear to slow their rate of growth in the presence of melittin.

Still, despite its potential medicinal uses, bee venom is a toxin. Patients should be informed of potential adverse reactions. Practitioners of venom therapy must be able to identify patients who have developed sensitivity, must be properly trained in managing severe reactions and must have rapid access to emergency care.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)