Posted tagged ‘eczema’

Vitamin D for winter eczema – Try it

January 28, 2016

The Pediatric Insider

© 2016 Roy Benaroch, MD

Eczema is a chronic, itchy skin condition seen in about 1 in 3 children. The skin is dry and scaly, and often red and inflamed. Eczema often seems to get worse in winter, in part because hot dry air from the furnace further dries out the skin.

Or, maybe, there’s another reason. Researchers in Ulaanbaatar, Mongolia (which, by the way, looks lovely) postulated that another reason for eczema to worsen in winter was decreased vitamin D levels. Most of us get our vitamin D from sunshine, and in the cold winters people spend less time outside. Less outside, less sunshine, less vitamin D. So what happens if you supplement children with eczema, and have them take a drop of extra vitamin D in the winter?

107 children were enrolled in the study, which was published in 2014. The average age was 9, and almost all of the children had what the authors characterized as “moderate” eczema. Half of the children were randomized to receive a vitamin D supplement (1000 IU once a day), and the other half a placebo drop; all of them were instructed to continue their typical eczema care, which usually consistent of skin moisturizers. A simple, clean study.

A month later, data were collected. There were no significant (or even mild) side effects in either group. 64% of the children who received extra vitamin D had improved skin, versus 43% in the control (placebo) group. Not a huge difference, but with an intervention that’s safe and cheap, that’s an important result that can potentially help a lot of children.

Some criticisms of the study: the authors didn’t check vitamin D levels before or after the intervention—so we don’t know if the children were actually vitamin D deficient, or if vitamin D supplementation was more likely to work in children with low levels. And the study didn’t involve many younger children (who are more likely to have eczema), and didn’t include any children less than 2 years of age.

Still: many children, we know, are vitamin D deficient, especially in the winter; and many children suffer from itchy eczema. At usual doses (like 1000 IU a day), vitamin D supplements are virtually free of risk. Worth a try, if your child has winter eczema? You bet.

Mongolia

Food allergy testing: Do those big panels work?

December 1, 2014

The Pediatric Insider

© 2014 Roy Benaroch, MD

Theresa asked about eczema (see last post), and also asked about food allergy panels. Does all of that testing help?

Well, usually, no.

It turns out that allergy testing (whether done by skin scratches or blood tests) doesn’t even test for allergy. We sort of smudge through that distinction, because it’s complicated. But it’s time for someone to spill the beans about this kind of testing, and here at The Pediatric Insider, we’re all about telling you guys “the real deal”—the inside info that docs typically keep to ourselves. Here’s something you may not want to hear: “allergy” testing is, well, just not very good.

Let’s start basic. An “allergy” is an adverse reaction (a bad thing, some kind of symptom) triggered by an exposure to something, and caused by a reaction of the immune system. It requires symptoms of some kind, and requires the symptoms to be caused by an immune reaction of some sort.

A broader term, “adverse reaction,” includes allergies but also non-immunologic reactions to things. For instance, many people get bloaty and gassey after ingesting milk. That’s typically caused by lactose intolerance, an inability to digest milk sugar that has nothing to do with any allergy. Still, lactose intolerance and gluten sensitivity and many other reactions are sometimes lumped in with allergies. They’re not allergic, and no “allergy testing” of any kind could possibly identify non-allergic reactions.

Also, allergy – an allergic reaction – requires some kind of symptom, and the symptom ought to be reproducible after exposures. Allergy “testing” often reveals “positives” to foods or other things that upon exposure doesn’t actually trigger a reaction. If eating a food you’ve tested positive for doesn’t cause a reaction, you are not allergic to the food. Period. Allergy requires symptoms.

And that’s the biggest issue with allergy testing—because these tests don’t test for allergy. They test for “sensitization”. They show that your immune system has the capacity to react to the substance, but that doesn’t necessarily mean that you will react to the substance.

I can’t tell you how many times I’ve heard from families who tested positive for food XX, though they’ve never had a reaction to XX—and in fact, they used to eat XX all the time. If your child eats peanuts routinely and doesn’t have a reaction, it doesn’t matter what the allergy testing shows. He is not allergic. The test shouldn’t have been done in the first place.

There are other problems with allergy testing. Though individual tests can fairly accurately say who is sensitized, each test does have a chance of a false result. If the rate of an incorrect test is, let’s say, 5%, that might sound pretty good. But what if you do a panel of 40 foods, each of which has a 5% chance of a false result? There’s a 88%* chance you’ll get at least one false positive. If the panel is large, you’re going to get false results. The larger the panel, the more wrong answers you’ll get. What then?

Another problem: there are a lot of ways to do allergy testing, and they’re not all the same, and I most families have no idea what they’re getting into. The current, most reliable blood testing for sensitivity is called a Cap-RAST or ImmunoCap, and it tests for specific IgE molecules. Older tests are far less accurate, and some still in wide use are as worthless as flipping a coin. If you are going to do allergy testing, you should at least do the best one. Skin testing, too, has different reagents and methods, and it can be difficult to know if what’s being done is the most-reliable testing.

About skin tests: they’ll be unreliable if the patient has been taking antihistamines, and they’ll be less reliable if the patient has a skin condition like eczema, which causes high overall IgE levels and a sort of overall hypersensitivity that leads to many false positives on both skin and blood testing. Testing children with eczema is fraught with peril, which is one reason many dermatologists aren’t keen on addressing the possible allergy-eczema connection.

Still, allergy testing can sometimes help, if you keep these points in mind:

  • Consult with a board-certified, genuine allergist. Many companies market allergy kits and tests and things for general practitioners and ENTs and who knows who else. They’re a big money maker, but we really don’t know what we’re doing with them or how well they work. Please stay away from alt-med practitioners who claim to be able to diagnose allergies by holding your hands or waving vials about or using some kind of elecromagnetic hyperscience quantumconfusionating walletemptier.
  • Test only for foods or other allergens that might be causing a reaction. Foods that are eaten routinely without problems are NOT allergies (and testing will lead only to confusion); foods that always do cause a reactions ARE allergies, and don’t have to be tested. Only test the grey-zone, “maybe” foods, or you’re asking for trouble.
  • Test a limited number of foods. Almost all food allergies are to a small number of candidates: milk, egg, wheat, soy, shellfish, fish-fish, peanuts, and treenuts. Tests for mustard and plantain and okra and lamb are unlikely to yield useful results, and might upset the lambs.
  • Think of allergy testing as a starting point, for clues to what might be a real allergy (positive tests), and clues for what are probably not causes of allergy (negative tests.) Under most circumstances, unless there’s been a life-threatening reaction, you have to confirm ‘allergy testing’ with deliberate exposures. And if there has been a life-threatening reaction, you probably already know what the trigger was—so why do the test?

* It has been a long time since I did statistics. What I did was figured the 5% chance of a false result on one test means that 19/20 times the test will be correct. So if you’re doing that 40 times I figure the chance of 40 correct tests in a row is 19/20 raised to the 40th power = ~ .12, and the chance of that not happening is 1-.12 = 88%. Am I even close? At The Pediatric Insider we welcome comments that point out boneheaded mistakes. Be gentle.

Allergies and eczema: Are they related?

November 24, 2014

The Pediatric Insider

© 2014 Roy Benaroch, MD

Theresa wrote in, “I’d be interested in seeing an article about the connection (or lack thereof) between food allergies and eczema. Also interested in the helpfulness (or lack thereof) of large blood panels for food allergy testing.”

Two good topics—and I’ll get to food allergy panels in the next post. First: What’s the connection between allergies and eczema?

Eczema is by far the most common chronic skin condition pediatricians see. It’s present in about 1 in 3 young children, or maybe more if you count the milder cases. In fact, if you look closely enough, just about every child has at least some eczema. It’s usually mild, and improves nicely with good skin care and the occasional use of low-strength topical steroids.

What causes the itchy, scaly, red rash? Many things seem to contribute: dry skin, rough fabrics, and scratching all make eczema worse. It often runs in families, and often occurs in the same children who later go on to have allergic rhinitis (hay fever), asthma, and food allergies (those conditions, as a group, are called “atopic.”) Eczema is also called “atopic dermatitis”—atopic referring to inflammation and sensitivity, typically caused by an allergic trigger. These conditions are all interrelated, and often co-exist. So is eczema, the rash, caused by a specific, identifiable, and avoidable allergic trigger?

There’s the controversy.  If you ask allergists, they’ll say “probably yes.” They stress identifying and avoiding specific triggers, typically one or more foods. Sometimes their advice is guided by allergy testing, or sometimes just by history, and sometimes by trial and error. Just avoid food X, and if that doesn’t work, avoid food Y. If there is an allergic food trigger, it’s probably one of the common food allergies, like egg, milk, wheat, soy, fish, or peanut. Maybe try avoiding those.

But it’s hard to avoid all of those foods—and “testing” will often lead to false positive or negative results. If food allergy does trigger eczema, it does it slowly, so it may take several days or weeks of restrictions and reintroductions of multiple, overlapping foods to figure this out. Meanwhile, Junior is still itchy. So the dermatologists take a different approach.

If you ask dermatologists if eczema is caused by food allergy, they’ll say “probably no.” They stress taking care of the skin (using good bathing techniques, moisturizers, sometimes topical antiinflammatory medications, and sometimes agents to reduce bacterial colonization.) Just treat the skin, that’s the dermatologists’ motto. We can make this better, and quickly, without anyone going hungry.

Now, if you ask pediatricians if food allergy causes eczema, we’ll say “sometimes.” Though some of us are probably more allergy-focused than others, most of us probably favor practical advice: for mild-to-moderate eczema, it’s usually best to focus on good skin care, and treat the eczema, and get Junior feeling better. IF initial, safe therapy doesn’t work, or if the eczema is severe, then we’ll also try to identify food triggers—though we’ll keep up the good skin care at the same time. One approach doesn’t mean you can’t also follow the other. And, in fact, the best dermatologists and allergists will also recommend this kind of middle-of-the-road, practical advice.

What about those food allergy panels Theresa asked about? Short answer: They don’t work, at least not if your goal is to figure out what your child is allergic to. More in the next post.

Bleach baths can help—just do them right

October 15, 2012

The Pediatric Insider

© 2012 Roy Benaroch, MD

“My doctor recommended that my child soak in a bleach bath to prevent staph. Can that be right?”

Whoa, wait just a minute here. Kids should NOT soak in undiluted bleach—no way, no how. I think there may have been a misunderstanding here. Diluted bleach baths can be a way to help prevent staph infections, but you need to do them correctly.

  1. Put about 10-12 inches of water in an ordinary-sized tub. If you’ve got one of those big garden tubs, that’ll be more water, so you’ll need to add more bleach in the next step.
  2. Add ¼ to ½ cup or ordinary household bleach. Not the ultra-concentrated stuff, the cheap ordinary stuff mama used to use.
  3. Add the child. Naked. Encourage him to scoot and move around, but let’s keep the splashing to a minimum. Ideally the water should come up to his chin. The most important body part to get under the water and move around is the butt and genitals.
  4. Soak for 5-10 minutes.
  5. Afterwards, drain the tub. Junior can take a regular shower if he wants, or just dry off and get dressed.

That amount of bleach adds a chlorine concentration similar to what’s in a swimming pool, and won’t hurt or bleach skin. It also won’t hurt if a little bit gets in the mouth.

Bleach baths can be done every day for a week or so to help treat an acute staph infection, and can then be continued about once a week to prevent recurrences. They’re also helpful to control eczema, which often flares up when skin is colonized with staph. They’re safe, they help, and they’re a good idea—just do ‘em right!