Dear Doctor: I got a flu shot this fall, but I still got sick. Why did this happen?

Dear Reader: Considering how this year’s flu season is shaping up, we’re not surprised by your question. According to the Centers for Disease Control and Prevention, which tracks weekly flu statistics, the current season started early and has been unusually severe. Flu has been reported in all 50 states.

The typical flu season runs from mid-fall to early spring, usually October through April. At this point, 46 states have reported widespread flu activity. And an unusual strain of the influenza virus is hitting harder than expected, particularly among children.

Influenza types A and B, two of the four known strains of influenza virus, account for the majority of illnesses. Type C is a milder form of the virus that is not associated with epidemics; type D appears in pigs and cattle, but not in humans. Historically, influenza type A accounts for three-fourths of all confirmed cases of the flu, with type B only showing up late in the season. However, this year, type B is making a stronger showing than type A, particularly in the southeastern U.S. This is important because of how each year’s flu vaccine is developed.

Designated global partners, including the CDC, work with the World Health Organization to collect and analyze thousands of influenza virus samples. The goal is to spot trends, and, because influenza is a master at mutating, identify new strains. Based on this data, scientists develop a vaccine that targets the top three or four influenza viruses expected in the coming flu season. Sometimes the vaccine does not cover the flu strain that has made you sick. And when widespread anomalies occur, such as with this season’s robust and early appearance of influenza type B, the vaccine isn’t as widely effective as desired.

As for why you became ill despite getting a flu shot, there are several possibilities. It takes up to two weeks to build up immunity after a vaccine. If you’re exposed to the flu during that interim, it’s possible to get sick. The flu vaccine doesn’t protect against all respiratory illnesses, so if you had a cold, often caused by the rhinovirus, the vaccine won’t offer protection. And as we discussed earlier, you may have been infected with an influenza strain not covered by this year’s vaccine. Even when this does happen, it is still advised that you get the vaccine every year. If you are vaccinated but do get the flu, studies show that the illness is more likely to be both milder and shorter. That’s important because the main difference between a cold and the flu is that flu symptoms are more severe, last longer and can cause grave and even life-threatening complications.

For readers who haven’t been vaccinated yet, it’s not too late. With three or four months in an already challenging flu season, it would be wise to get your flu shot ASAP.

(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: Every winter I get these weird bumps on my skin, kind of like goosebumps, except that they won’t go away. What are they? Is there anything that can help?

Dear Reader: It sounds as though you’re describing a common and harmless skin condition known as keratosis pilaris. Symptoms typically include patches of small, hard bumps that are about the size of a grain of sand. They may match your skin tone, or can appear pink, reddish, white or brown. In some cases, the tops of the bumps are covered in dry skin scales.

The condition occurs when oil pores in the skin, which also contain tiny hairs, become clogged with dead skin cells. (The word “keratosis” refers to keratin, the main building block of the epidermis, or outer layer of the skin. The word “pilaris” pertains to hair.) The affected area becomes rough and in some cases may itch. However, keratosis pilaris doesn’t cause pain.

This is a condition that may be seasonal, as you have experienced, or can last for months or even years. It usually appears on the skin of the upper arm, upper thigh or buttocks, but can also develop on other areas of the body. It sometimes occurs on the face, most often on cheeks, where it resembles acne. It’s more common in young people, and often goes away as they get older. The cause of keratosis pilaris isn’t yet known, but since it’s more common in individuals with certain skin conditions, such as eczema, genes may play a role. It’s distinctive enough that it can usually be diagnosed with a visual and physical exam.

Keratosis pilaris is neither harmful nor dangerous, and it isn’t infectious. It can safely be left alone. But if you’re bothered by the appearance, or if you’re experiencing itchiness, you have several treatment options. Since damp skin absorbs moisturizer more easily than dry skin, and since the products form a barrier that protects the skin, make it a practice to apply moisturizer after bathing or showering. Creams that contain chemical exfoliators -- such as urea, salicylic and glycolic acid, and alpha hydroxy acids -- can help to break down excess keratin. Over-the-counter lotions such as Eucerin, AmLactin and CeraVe, which are gentle and fragrance-free, can be helpful in diminishing the size of the bumps and boosting moisture.

When showering and bathing, keep water on the cooler side, as hot water can contribute to dry skin and irritation. Using a loofah, washcloth or exfoliating mitt can also help minimize bumps, but don’t try to scrub them away. This can easily lead to irritated or even inflamed skin and make symptoms worse. Instead, treat your skin gently.

When toweling off after a shower or bath, dab your skin dry rather than rubbing. If you’re not getting results with this regimen of self-care, your health care provider can recommend prescription creams with vitamin A or Retin-A, which may help improve your skin’s appearance.

(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: I am bothered by certain scents, especially from candles. What causes it? And other than moving away from the source, is there anything I can do to combat this problem?

Dear Reader: When it comes to having an adverse reaction to the scents and fragrances that are routinely added to thousands of products, you are far from alone. About a decade ago, researchers found that more than 30% of the general American population considered scented products irritating. A similar 2016 study put that number at nearly 35%. Participants in both studies reported that even brief exposure to a fragranced product could result in a migraine headache; trigger an asthma attack or other respiratory difficulty; and cause dizziness, fatigue, problems concentrating, numbness, nausea and skin rash. Scented and perfumed items that caused these problems included the candles that you struggle with, as well as cleaning products, laundry soaps, personal care products, dryer sheets, trash can liners and, of course, perfumes, aftershaves and colognes.

Scented products -- even those advertised as being natural, “green” or organic -- emit a wide array of volatile compounds, including some considered to be hazardous pollutants. We notice their scent when airborne molecules enter the nose and activate the complex network of receptor sites and nerves that translate a chemical structure into a specific smell. People who have an adverse reaction to these added scents are said to have a chemical sensitivity. Some are bothered by one or two types of chemicals, while others struggle with multiple sensitivities.

Unfortunately, it’s virtually impossible to identify exactly which compounds are at fault. That’s because, unlike the ingredients of a product, fragrance is considered to be a trade secret. Manufacturers aren’t required to disclose the specific chemicals they use to scent their products.

Awareness of the problem is growing. Some states are proposing laws to require manufacturers to disclose all chemical ingredients on their packaging. A 2016 legal ruling allowed multiple chemical sensitivity to be categorized as a disability, which lets -- or requires -- employers enforce fragrance-free policies when an employee has a condition that substantially limits one or more life activities. So if you have a minor allergy to a fragrance that causes a runny nose, you are not entitled to an accommodation, but if the allergy interferes with your breathing, you are.

Meanwhile, for the general population -- and in answer to your final question -- avoidance is the only real solution. And again, when you walk away to avoid the effects of a scented candle, you’re not alone. Studies have found that one-fifth of people will exit a store to avoid the headache or stuffy nose that airborne fragrances can cause. Fully 15% of people report missing work due to sensitivity to added scents or fragrances. Some even avoid washing their hands in a public bathroom that offers only scented soap.

You can learn more about the issue from the Chemical Sensitivity Foundation at chemicalsensitivityfoundation.org.

(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.)