Hello again, dear readers, and welcome to the monthly letters column. You’ve kept our mailboxes busy, so we’re diving right in.

-- We recently answered a question about whether or not the tea, coffee and juicy fruits and vegetables that someone consumes help with hydration. The answer is yes, they do. Now a reader asks specifically about sodas: “I find that reliable information about the safety of drinking soda pop is hard to come by,” she wrote. “Should it be avoided?” In a word, yes.

Sugary beverages like soda are linked to a long list of adverse health effects, starting with obesity, poor blood sugar control and diabetes. Recent studies have found an association with high blood pressure, high cholesterol and heart disease. Research shows that having as little as one soda per day measurably increases the risk of developing Type 2 diabetes. And diet sodas, which have been found to increase hunger and disrupt metabolism, are not any better.

If you crave bubbles, you could give one of the flavored and unsweetened sparkling waters that are widely available a try.

-- In a previous column about wound care, we explained that a cut or scrape should be gently cleaned with mild soap and cool running water. This led a reader to propose a different scenario. “When needing to clean a minor cut or scrape, what is best to use if mild soap and running water are not available?” they asked. One of your primary goals with any cut or scrape is to prevent infection. That means cleansing the wound of any dirt or bacteria that may have become imbedded when the injury occurred. If clean water of any kind isn’t immediately available, you’ll want to protect the broken skin from dirt or further injury by wrapping it with a clean covering. To be clear, this is a stopgap solution until you reach a place where the wound can be properly cleaned and bandaged.

-- A column about medical-grade honey, which is honey that has been sterilized to be safe for use in a medical setting, continues to get a lot of mail. Due to its antimicrobial properties, medical-grade honey is sometimes used in burn and wound care. This caught the attention of a reader whose daughter is living with scleroderma, a disease that involves the hardening and tightening of the skin. “My daughter has developed open ulcers on her feet and hands,” she wrote. “Do you think that medical-grade honey will help them heal faster?”

A hallmark of scleroderma is a narrowing of the blood vessels, which leads to poor circulation. For this reason, patients often develop open sores. While there are case studies that have found a benefit in using medical-grade honey to treat open sores associated with scleroderma, clinical trials into the practice are lacking. It would be a good idea to broach the topic of medical-grade honey in your daughter’s case with your daughter’s physician or care team.

Thank you again to everyone who took the time to write. We appreciate your comments and are grateful for your kind thoughts.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: I’m concerned about a large lipoma that is growing on the right side of my head. I know that lipomas are not supposed to be cancerous, but can it become so in the future? I’m considering having it removed. How is that done?

Dear Reader: A lipoma is a harmless rounded mass that forms due to an overgrowth of fat cells. Often shaped like a dome, lipomas usually don’t cause pain or any other symptoms. Lipomas are typically found just below the surface of the skin, often on the trunk, neck, limbs or forehead. Less often, they may form within a muscle or inside an organ. When you touch a lipoma, the tissue feels rubbery and a bit springy. Because the mass isn’t directly attached to the underlying muscle, it moves easily beneath the skin in response to pressure.

Discovering a lipoma can be alarming, particularly since they are technically tumors. However, they are benign, which means lipomas are not cancerous. It is estimated that 1% to 2% of people will develop a lipoma in their lifetime. The reason for this is not yet known. In some individuals, genetics appears to play a role. An inherited condition, known as familial multiple lipomatosis, can cause someone to develop numerous fatty growths on their body, some of them quite large. This condition arises due to a faulty gene that has been passed down, and it is not common.

Lipomas occur slightly more often in men than in women, and although they can appear at any age, they become more common in adults between the ages of 40 and 70. In addition to fat cells, some lipomas may contain blood vessels or other tissues.

While it’s possible for a lipoma to become malignant, this is quite rare. When it occurs, the growth is known as a cancerous liposarcoma. For that reason, it’s important to let your health care provider know about any changes to an existing lipoma, including its size, shape, texture or appearance, and if it begins to cause discomfort or pain. If a malignancy is suspected, a biopsy will be performed. This will reveal if cancer is present.

Although a lipoma doesn’t present any medical risk, sometimes the decision is made to remove it. This may be for cosmetic reasons, to relieve pressure on a nerve, or when its size or location leads to discomfort. Complete removal of a lipoma involves a small operation, which can be performed under local anesthetic. The surgeon makes an incision and then frees the lipoma from the surrounding tissue. The mass is then removed, and the incision closed with sutures. Post-operative pain and bruising may occur, and the patient may be left with a visible scar. It is rare for a lipoma that has been surgically removed to recur.

When a lipoma is large, liposuction may be used to reduce it. This involves the use of a needle and a large syringe to remove the fatty deposit. Each of these are outpatient procedures and do not require a hospital stay.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: When my nephew was born last year, he had something the doctors called neonatal jaundice. It went away after a few weeks, and he seemed fine. Then the same thing happened when I had my daughter. Why do babies get jaundice? Is it dangerous for them?

Dear Reader: Neonatal jaundice is a common condition in which a baby’s skin and eyes take on a yellowish tint within the first few days of birth. It occurs in up to two-thirds of all healthy newborns, and in the majority of cases, it does not indicate a health problem.

Let’s start with the name of the condition itself. The word “neonatal” refers to the first four weeks of an infant’s life. The term “jaundice” comes from the word “jaune,” which means yellow in French.

The reason that jaundice causes a change to skin color is due to a buildup in the blood of a compound known as bilirubin, which is yellowish in color. Bilirubin is a natural byproduct of the breakdown of aging red blood cells. As blood circulates through the liver, the bilirubin that it contains is filtered out. The liver then breaks down the captured bilirubin into a form that the body can get rid of. These final compounds are sent to the small intestine where, after being further dismantled by certain bacteria, they exit the body via the stool.

While the baby is still in the womb, bilirubin is removed from the blood via the placenta. After birth, however, that job falls to the baby’s own organs. A newborn’s liver can take a bit of time to begin to function efficiently. At the same time, newborns have greater numbers of red cells than adults or older children, and the cells have a shorter life cycle. These two factors can easily lead to a buildup of bilirubin in the infant’s blood. It can take a bit of time, sometimes up to two weeks, for the baby’s liver to become effective at filtering bilirubin from the blood.

The symptoms of neonatal jaundice begin in the face, then move to the chest, belly and legs. In babies with darker skin, this change in color is sometimes easier to discern on the palms of the hands and soles of the feet.

In the majority of babies, neonatal jaundice will resolve on its own, usually after a few days to two weeks. It’s just a matter of waiting for the infant’s liver to catch up to the amount of bilirubin that needs to be removed.

In very rare cases, the condition can signal a more serious problem. When bilirubin levels become high, babies can experience changes to behavior as well as to appearance. Behavior changes can include becoming fussy, poor feeding, developing floppy limbs and being unusually sleepy. If a problem is suspected, a blood test may be used to help with diagnosis.

Treatment can vary, from addressing potential dehydration with increased liquid intake to a range of medical interventions. All of this makes it important to have a health care provider monitor the course of neonatal jaundice.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)