Unwind the ‘story’ to diagnose asthma, allergies

Every asthma or allergy patient has a story, according to John M. Kelso, MD, of the Scripps Clinic Division of Allergy, Asthma, and Immunology in San Diego. The details of these stories tell the internist how best to manage and treat several conditions that are interrelated and frequently comorbid.

“These patients walk into our offices every day, and I hope to arm you with some practical pearls about how to approach some of these common allergic diseases,” said Dr. Kelso, who went on to address a potpourri of topics, including asthma control, allergic rhinitis, and food and drug allergies, at his Internal Medicine Meeting 2016 session, “Common Allergic Problems: An Update.”

Asthma control vs. severity

It's very important to differentiate between asthma severity and asthma control, Dr. Kelso said.

The algorithm for categorizing asthma severity is complex, with components and classifications offering dozens of options. “Somehow [patients are] supposed to end up in a box describing their asthma severity. I find this of no utility at all,” Dr. Kelso said.

Another categorization challenge is whether severity should change if asthma improves with treatment. “If somebody has normal spirometry and rare symptoms, meaning their asthma is under good control, you might think that means they have mild asthma,” he said. “But what if it requires a lot of medication to achieve that? What category does that put them in?”

Dr. Kelso also questioned the usefulness of categories of asthma control, which were introduced in the 2007 by the National Heart, Lung, and Blood Institute National Asthma Education and Prevention Program in their “Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma.”

“I think that's a great idea,” Dr. Kelso said. “But they still made it too complicated. There's fewer boxes there, but as far as I'm concerned, there's still too many boxes. ... They couldn't have controlled or not. They had to have well controlled, not well controlled, and very poorly controlled.”

Asthma control categories aren't stable over time either. One study found that patients' categories changed as much as 15 times over a 12-week span, Dr. Kelso reported.

Dr. Kelso clarified that good control means just 2 things: The patient shouldn't need albuterol very often, and lung function should be normal.

Routine use of spirometry can help the internist determine this, Dr. Kelso said, by establishing the asthma diagnosis and tracking severity and control over time. So, use it at every visit, he recommended. For example, if a patient reports symptoms and is prescribed prednisone and a return visit in 1 week, spirometry should be performed at that 1-week visit. Even if the patient has no symptoms and doesn't need to return for 6 months, check spirometry at that next visit, he said.

“Another important reason that we're following spirometry over time in patients with asthma is that there are patients who have permanent airway reconstruction for no other reason than they had asthma, called airway remodeling,” he said. Spirometry will track this steady decline in lung function and signal the need for more intense therapy, he noted.

To measure the other aspect of control, albuterol use, simply ask the patient to recall use in terms of times per week or per month, Dr. Kelso said. “And then the next question, which again might seem obvious but is worth asking, is, ‘When you have a cough, and you use your albuterol, does it help?’ Within minutes there should be some obvious improvement in those symptoms. That's what you want to hear to reassure you that those really are asthma symptoms,” he said.

Also ask whether patients wake up in the middle of the night to use albuterol, “because that shouldn't be happening at all,” Dr. Kelso said. “And if patients have symptoms onset due to exercise, do they use albuterol prior to running, and again, if they do, does it help? Does it allow them to run as far and fast as they want to?”

Allergic rhinitis

Another common cause of primary care visits is IgE-potentiated disease exacerbated by airborne allergens. Dr. Kelso offered advice on taking a history from such patients.

First, the majority of people with allergic rhinitis really have allergic rhinoconjunctivitis, because they report eye symptoms as well. Ask if there is a runny nose, then check for runny eyes. Is the nose itchy? Probably, and if so, the eyes as well. Does the patient have red eyes? Dr. Kelso said that conjunctival congestion that leads to red blood vessels in the eyes also happens in the nose, where the swollen blood vessels are the main contributor when people say they have a stuffy nose or their nose is blocked, rather than mucus.

If patients add that they have an itchy palate, or itchy ear canals, those people have allergic rhinitis. “That's practically a guarantee,” said Dr. Kelso.

Things not to bother asking include how old the person's house is, what kind of carpet they have, how old a mattress is, or if patients live near the ocean, Dr. Kelso advised. “I don't know what I'm supposed to do with that information.”

Instead, ask about the seasonality of the symptoms. Do it in a way that doesn't suggest the spring and the fall, because that's when patients know it's supposed to be worse, he advised. “So the way that I ask that question is, ‘Are there times of year when your symptoms are worse, or not really?’ to allow them to say ‘I really don't notice a difference.’”

Pets are another potential allergen, specifically their dander, which remains airborne indefinitely. That's why people who are allergic to cats walk into a house and react right away, even if the cat is not in the same room, Dr. Kelso said.

An internist should ask patients whether they own pets, how many, and what species (including not only cats and dogs but any pet with fur, such as rabbits and guinea pigs), but there's no need to know what breed. A study from 2012 published in the Journal of Allergy and Clinical Immunology measured the amount of allergens floating around inside the homes of people with allegedly hypoallergenic breeds of dogs, such as labradoodles, poodles, and Spanish water dogs, and compared it with allergen levels in the homes of people with golden retrievers and similar long-haired breeds. The amount of dog allergen in the air was exactly the same. “So there really is no such thing as a hypoallergenic pet,” Dr. Kelso said.

For patients with pet allergies, you can first try telling them to find a new home for the pet, but “That's not going to happen,” Dr. Kelso said. Next, tell them to keep the pet outside so it never ever comes in the house, although this may not be feasible or acceptable for many patients. Also, advise them not to acquire any more pets. The current pet should be excluded from the bedroom to prevent a repository of allergens getting recirculated. This is one of the few times when running high-efficiency particulate arrest (HEPA) air circulators is helpful, Dr. Kelso said. “Run one in the bedroom and one in the family room and that will help clean the pet allergen out of the air.”

Mold is another potential allergen, and physicians should ask if patients can see or smell mold in their homes. If they can, they will need to find the source of the water leak or intrusion that allows a moisture source for the mold growth and fix it, as well as cleaning up the mold, Dr. Kelso said. Other solutions could include running a dehumidifier or the air conditioner to reduce the indoor humidity, he noted.

For pollen allergies, don't tell people to follow the pollen counts or only be outside at certain hours, but instead treat the symptoms and tell patients to go outside when they want, Dr. Kelso advised. Patients may want to remove trees or replace grass with rocks, but allergy symptoms are not a product of the immediate environment, since pollen travels a very long way, he said. In contrast, no one is allergic to roses or daisies. Flowers have heavy, sticky pollen that is not windborne, so people don't become allergic to those things, Dr. Kelso said.

Dust mites are the next major environmental culprit in allergic rhinitis. The mites themselves and their fecal matter both contain allergens, and both get pulverized and become airborne. Dust mite particles are heavy and will settle out of the air. Dust mites love humidity, so in this case, patients should not run a humidifier, and if they live in a humid place, they certainly should run a dehumidifier or at least the air conditioner, Dr. Kelso noted.

Dust mites' major food source is shed skin, which accumulates in pillows and blankets. Hypoallergenic mattresses and pillows fill up with dust mites too, so they will require encasings and a mattress pad that gets washed with the sheets and pillowcases in hot water every few weeks, Dr. Kelso said.

To avoid allergens, it's best to not have carpet, Dr. Kelso said, or to vacuum it once a week or so. “You don't need a $500 allergy vacuum. Whatever vacuum you have is fine,” he said. Even if the vacuum doesn't emit anything, the act of vacuuming stirs up allergens, so the allergic patient shouldn't vacuum him- or herself or should wear a mask to do so.

Food allergies

Patients who suspect they have food allergies often tell their physicians that they ate something and think they had an allergic reaction to it. “So what's a good story for a food allergy? When should we be concerned?” Dr. Kelso asked.

The list is short for foods that are responsible for almost all food allergies, Dr. Kelso said: milk, eggs, nuts, fish and shellfish, legumes (mainly peanuts and occasionally soy). Milk and egg allergies are quite common among children but are very unusual in adults, he said. Nuts like almonds, walnuts and cashews are sometimes called true nuts or tree nuts to distinguish them from peanuts, which are legumes.

With food allergies, reactions happen shortly after eating the food, within minutes and maybe up to a couple of hours. “Beyond that, it wasn't the food,” Dr. Kelso said. “A lot of times, the patients tell you what they had for dinner the night before. It's way too late by then. Or they tell you they've been eating more of this food lately. The nature of the reaction should sound like something that was mast-cell mediated.”

Internists most often test for a food allergies with a blood test. Skin tests are more often performed in allergist's offices where occasionally patients are asked to bring in the suspect food to test with. “When someone tells you a food allergy story, please don't order the [entire] food allergy panel,” Dr. Kelso said. “Only test for the foods that you are suspicious of, or related foods.”

He also emphasized that every patient diagnosed with a food allergy should be prescribed epinephrine autoinjectors.

Drug allergies

Like food allergies, the list of drug allergies is short, and the predominant one is penicillin. Dr. Kelso said that about 10% of patients self-report this allergy but of these, only 5% to 10% of patients are actually allergic. The rest were either never allergic or they were allergic in the past but are no longer.

Formerly, internists avoided reported penicillin allergies by just prescribing something else. But the replacement antibiotic may be suboptimal and will probably be more expensive, Dr. Kelso said. This practice also promotes antibiotic resistance and may lead to more side effects, such as Clostridium difficile infection. “It is not benign to give your patient something other than penicillin just because you think they are penicillin allergic. It is worth finding out whether they are or are not,” Dr. Kelso said.

It's appropriate to refer to an allergist a patient who says he or she is allergic to penicillin, Dr. Kelso noted. Allergists administer a skin test, as the blood serum test for penicillin has very poor sensitivity and specificity. If skin tests are negative, the allergist can challenge the patient with a dose of amoxicillin and follow the person for an hour and make sure that he or she doesn't have a reaction. Up to 95% of people with suspected penicillin allergies are not penicillin allergic, and the doctor can then “de-label” them, he said.