Dear Doctor: I was just diagnosed with erosive osteoarthritis. What can you tell me about it? I have it mainly in my hands and feet.

Dear Doctor: First, let's explain the most common form of arthritis, known simply as osteoarthritis, which develops slowly over time due to complex changes in cartilage, bone and joint linings. Formerly known as "wear and tear" arthritis, osteoarthritis has no inflammatory component and typically occurs in multiple joints throughout the body. Erosive osteoarthritis, on the other hand, is an inflammatory form of the disease that occurs primarily in the hands and, sometimes, in the feet.

In the hands, erosive osteoarthritis develops earlier in life than does typical osteoarthritis, usually between the ages of 40 and 50. It's most commonly diagnosed in women (rarely men) at the time of menopause, suggesting that loss of estrogen is a factor.

Unlike typical osteoarthritis, erosive osteoarthritis has a sudden and aggressive onset. The hand joints become warm, red, swollen and tender, making it difficult to move the fingers. With this degree of inflammation, the disease can look much like rheumatoid arthritis, but unlike rheumatoid arthritis, erosive osteoarthritis involves the joints at the end of the fingers. Bony swellings develop upon these joints, creating what appears to be nodules. The joints lose their structure so much that the finger bones move laterally in opposite directions, making the fingers look wavy instead of straight.

The inflammation can cause cartilage and bone in the joint to erode, giving the disease its name. In severe cases, the joints fuse, making movement almost impossible. The inflammatory course of the disease can last for months or come and go for up to five years. However, even when the inflammation subsides, the damage leads to long-term deformities and loss of function of the involved joints.

There are no specific lab tests to diagnose erosive osteoarthritis. Your doctor may have done blood tests to rule out diseases such as rheumatoid arthritis, but the symptoms in your hands and feet were his or her greatest clue. Patients may have some elevated inflammatory markers, but the disease is primarily diagnosed by a person's symptoms. X-rays of the hands can show specific erosions in the bones that are unique to the disease.

Decreasing inflammation is the first place to start. This can be done with topical anti-inflammatories such as diclofenac or oral anti-inflammatories such as ibuprofen, naproxen, meloxicam or celecoxib. Drugs used for rheumatoid arthritis can also ease the inflammation and erosion of erosive osteoarthritis. These include hydroxychloroquine, methotrexate and the injectable drug Humira. For severe cases, injecting steroids directly into the finger joints can decrease deformities. Also, though the data are limited, one study showed a decrease in erosions and improvement of symptoms among people taking 800 milligrams of the supplement chondroitin in addition to Naprosyn (naproxen).

Physical therapy can also improve finger mobility and reduce the likelihood that the fingers will become excessively crooked.

My advice is to treat the disease early. Although the inflammatory portion of erosive osteoarthritis is relatively short, controlling the inflammation with medication and getting hand therapy will reduce the likelihood of the deformities that can happen with the disease.

(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: I read that spending too many hours on social media is linked to an increase in teen depression and suicidal thoughts. I worry about my own kids, but what can we do? Everything is online now, and I don't want my kids to be outcasts.

Dear Reader: Navigating the often-fraught transition from childhood to adulthood has never been easy. Whether we're reaching back centuries to the passions of Shakespeare's doomed pairing of Romeo and Juliet, glancing back decades to the alienation of Holden Caulfield in "The Catcher in the Rye," or clicking the "follow" button on any of the current crop of pretty-please-look-at-me young social media stars, the challenges of being a teenager remain the same.

Adolescence is a time of swift and bewildering change. It's often accompanied by hyper-awareness of one's self, a deep need to fit in, and the sometimes-contradictory wish to stand out. It's no surprise that in the thundering echo chamber of social media, where every move gets not just scrutiny but also instant (and often merciless) judgment, kids get emotionally overwhelmed.

The goal of the study was to learn whether the online ecosystem, which devours so much of our kids' time and attention, has a role in the recent increase in symptoms of depression and suicidal thoughts among adolescents. Headed by a psychologist from San Diego State University, researchers parsed the results of national surveys whose questions delved into the mental health of 500,000 young people between the ages of 13 and 18.

The findings, published last November in the journal Clinical Psychological Science, suggested that increased screen time may indeed contribute to, or worsen, adolescents' feelings of alienation and loneliness. This proved to be particularly true of girls, whose screen time skews to social media platforms, with their highly visible currency of accumulated "likes." Boys tend to gravitate to online games, the study said, where prowess is valued over looks or personality. Overall, increased screen time equaled increased feelings of depression.

Though the study results do suggest a link between increased online time and feelings of isolation, researchers admit they fall short of proof. Based on the data, though, the authors recommend keeping online time to less than three hours per day.

And, yes, we can hear your sigh of frustration from here. Because the truth is that being online is quite literally addictive. As you said in your question, kids who don't take part can get left out. Limiting screen time is, at best, an ongoing struggle. At worst, it's a bruising battleground.

Still, basic online hygiene is important. A good starting point would be no screens at meals and no screens overnight in bedrooms. This has to apply to adults as well, or it's not going to work. We believe that the other half of the equation is increasing human contact. Have your kids invite friends over to your house for activities on a regular basis. Start a weekly family fun day. Get your teens involved in volunteer work. (Something that correlates to existing interests has the best chance of success.) Even a small shift offline and into the real world can make a difference.

(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: There is an ongoing debate in my house about fluid/water intake to keep hydrated. Doesn't it make sense to drink water primarily when you feel thirsty? If not, how much do you need?

Dear Reader: Many of my patients ask how much water they should drink per day, and I give different estimations based upon their individual kidney and heart function. But I feel somewhat at a loss on what to tell them in a broad sense.

Current medical belief holds that an individual should drink eight 8-ounce glasses of water per day for a daily total of a half-gallon, or roughly 2 liters. Although thirst might logically seem to be a good indicator, some people are less likely to get thirsty due to illness, age or simply because they've grown accustomed to drinking little water. So it's better to keep an eye on total intake.

But the science on that intake is based on very few studies.

One 2002 study asked 20,297 Seventh-day Adventists -- average age of 58 with no history of diabetes -- about daily fluid intake, then followed them for six years. Men who drank five or more glasses of water per day had a 64 percent reduction in fatal heart disease compared to men who drank two glasses or fewer. Women who drank five or more glasses of water per day had a 41 percent reduction compared to those who drank two glasses or fewer.

When the researchers assessed intake of other fluids (coffee, tea, milk, juice, soft drinks), they found an opposite correlation. Men who drank more than five glasses had a 46 percent increased risk of fatal heart disease compared to men who drank two glasses or fewer. In women, this increase was a dramatic 247 percent.

A 2010 study from the Netherlands asked 120,852 people about their fluid intake, then followed them for 10 years. Here, neither increased water intake nor total fluid intake was correlated with a risk of fatal heart attacks or with strokes.

Then there was a 2012 study of 465 stroke patients who were followed for 17 months. It found a 27 percent decreased risk of stroke, heart attack or death among people who drank 2 or more liters of total fluid per day versus those who drank less.

As for older adults, a 2017 study assessed fluid intake among 1,055 Australian women over the age of 70, then followed them for 10 years. No association was found between death rates and either water intake or total intake of fluids.

Notably, in various other studies, higher water intake has been linked to a lower rate of kidney disease. Because kidney disease has been associated with higher rates of cardiovascular disease, this connection may be why there is less death from heart disease among people with higher fluid intake. This may be more applicable to an older population.

Of course, the amount of water you need to drink depends on losses of water from sweating or from illness and from fluid obtained via food (soups, vegetables, fruits and so on). Although the data are hardly ironclad, it seems to me that five glasses of water per day is healthy.

(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.)