Dear Doctor: I've been taking a drug for blood pressure issues for a couple of years, but now I hear it's being recalled. What's the risk? Should I stop taking it?

Dear Reader: You're referring to valsartan, an oral medication that belongs to a class of drugs known as angiotensin receptor blockers, often referred to simply as ARBs. The drug, which works by blocking a certain chemical that causes blood vessels to constrict, is prescribed for individuals with high blood pressure. It is also used to treat congestive heart failure and may be prescribed following a heart attack. Last summer, the U.S. Food and Drug Administration announced a voluntary recall of several blood pressure medications that contain valsartan, due to the presence of a particular chemical which has been identified as a probable human carcinogen. After trace amounts of another type of potential carcinogen were detected, the FDA not only widened the recall to include more blood pressure medications, but it also issued a warning to the manufacturer, Zhejiang Huahai Pharmaceuticals in China.

Since the start of the initial recall in July 2018, investigators uncovered additional concerns, which have resulted in an ever-widening FDA recall. At this time, the agency has increased the recall list to include dozens of drugs used to treat hypertension, all due to the presence of trace impurities that are associated with cancer risk. In addition to many types of valsartan, the recall now includes losartan potassium tablets USP, as well as irbesartan tablets, which are also used to treat hypertension.

The FDA has set up several web pages to help consumers identify whether or not their particular medications are affected.

-- The recalled valsartan drugs are numerous. The list is 11 pages long and the print is pretty small, so get ready to use the zoom function on your device. You can find this list at fda.gov/downloads/Drugs/DrugSafety/UCM615703.pdf.

-- The FDA has also created a website that lists valsartan drugs that are OK and have not been recalled. You can find that one at fda.gov/downloads/Drugs/DrugSafety/UCM615704.pdf.

-- To check whether your type of potassium tablets is on the recall list, visit fda.gov/Safety/Recalls/ucm629261.htm.

-- Information about the recall of irbesartan tablets is available at fda.gov/Safety/Recalls/ucm624593.htm.

The affected drugs are being recalled due to the presence of trace amounts of either N-nitrosodimethylamine (NDMA) or N-nitrosodiethylamine (NDEA), chemical compounds that have been identified as probable carcinogens. The latter chemical has been the subject of research that also associates it with liver and blood cell damage. According to the FDA, the chance of developing cancer as a result of taking these drugs is very small.

If your particular medication is on the recall list, do not stop taking it. The medical risk of suddenly going unmedicated is far higher than the cancer risk posed by the drug. Instead, contact your physician immediately. Let him or her know your prescription is on the FDA recall list and make arrangements to find an alternative as quickly as possible.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My wife read that a man had his legs amputated after he got an infection from being licked by his dog, and now she's freaking out. She's afraid to even touch our dog anymore, lest it somehow get saliva on her. Please talk some sense into her.

Dear Reader: We can understand your wife's initial sense of alarm regarding this story and suspect her reaction has been shared by quite a few others. The idea that just a lick from a beloved family pet can have such dire consequences is indeed disturbing. But before we get to the specifics, we're glad to offer your wife reassurance that what happened in this case is extremely rare.

According to news reports, a 48-year-old man from Wisconsin was rushed to the hospital after symptoms similar to the flu -- fever, vomiting, and aches and pains -- quickly escalated. His fever spiked high enough that he became delirious, and bruises suddenly began to appear on his limbs, face and torso. The doctors in Wisconsin fought the infection with antibiotics for a week but were unable to stop its progress. In order to save the man's life, parts of his legs and hands had to be amputated. The man was diagnosed with a rare blood infection caused by the bacterium Capnocytophaga canimorsus, which is found in the saliva of many healthy dogs. Prior to becoming ill, the man had contact with several dogs, including the family pet.

The vast majority of the time, Capnocytophaga isn't harmful to humans. In rare instances, however, an infection with the bacterium can cause the immune system to go into overdrive. This happens most often in individuals whose immune systems have been weakened due to certain medical conditions like HIV or lupus, chemotherapy drugs or having had a splenectomy.

Transmission of Capnocytophaga canimorsus most commonly occurs via a dog bite, and less often through close contact in which saliva may be transferred. Although cats are also carriers of the bacterium, infection is most often linked to dogs.

Most people who become ill due to Capnocytophaga will begin to exhibit symptoms between three and five days after contact. In some cases, it can be as fast as one day, and can take up to two weeks. Symptoms of illness can include:

-- The formation of small blisters around the bite wound, sometimes beginning within an hour of the bite

-- Pain, swelling, redness or pus at the site of the wound

-- Elevated temperature, which may spike to a high fever

-- Stomach pain, often accompanied by diarrhea

-- Nausea and vomiting

-- Headache, sometimes accompanied by confusion

-- Aches and pains in the muscles and joints

If you have any of these symptoms following a dog bite, seek immediate medical help. In fact, any time that you get bitten by an animal, you should first thoroughly wash the area with soap and water, then immediately see a doctor. Not only is there the risk of infection, but animal bites can put you at risk for rabies as well.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Hello again, dear readers! We hope that amid the rush (and, let's face it, occasional stress) of the holidays, you were able to enjoy the season. We thank you for making the time to keep our mailboxes full. We will get right down to business.

-- In response to recent columns about organic foods and pesticides, a number of you asked how to effectively wash apples, which regularly find their way into lunch boxes and snack trays. We did a bit of research and found a study published last October in the Journal of Agricultural and Food Chemistry that says a soak in baking soda is the most effective way to get rid of pesticide residue. According to researchers at the University of Massachusetts in Amherst, a 12- to 15-minute soak in a baking soda solution successfully removed common fungicides and pesticides from the apple peel. This worked better than rinsing with water or washing with bleach.

However, because some pesticides penetrate the skin, the conclusion was that the only surefire way to avoid the chemicals was to completely peel the apple.

-- In addressing the potential dangers of recent outbreaks of measles, mumps and chicken pox, we touched on the need to stay current with vaccines. Several of you wondered if, after initial completion of all early childhood vaccinations, follow-up vaccinations are actually necessary. The answer is emphatically yes. A child's immune system is not fully developed, and vaccination schedules are structured to address that. When subsequent boosters are called for, it's because they are needed to confer full protective immunity. If your family has fallen behind on vaccinations, get in touch with your family doctor. He or she will be glad to help you get back on schedule.

-- Another extremely popular topic in our mailbox, likely in response to all the cookie baking that took place over the holidays, was whether eating raw cookie dough is really dangerous enough to warrant a warning from the FDA. Although it's true that the risk of illness is small, it's real. That's because two ingredients in raw cookie dough -- eggs and flour -- can be contaminated with dangerous pathogens.

In the summer of 2016, it was discovered that multiple brands of all-purpose flour were contaminated with E. coli, a nasty intestinal bug that can cause serious illness. Add that to the known risks of contamination of raw eggs by Salmonella, and raw cookie dough becomes risky.

That said, if you can't reliably keep your little (or big) family members away from the mixing bowl, you can take steps to make the dough a bit safer. Regarding flour, check the Food and Drug Administration website for the latest information on any recalls. If your batch of flour is cited, dump it. As for eggs, consider baking with the pasteurized variety, which have been exposed to enough heat to destroy potential bacteria.

Some heat-sensitive vitamins, such as riboflavin, thiamin and folic acid, are lost as a result of the pasteurization process. However, when it comes to raw cookie dough, we suspect nutritional value isn't the main concern.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)