Friday, September 28, 2012

Small study suggests anti-itch "hydrogel" effective

A small study of an anti-itch "hydrogel" conducted in North Carolina showed promising results, according to a report in the dermatology journal Cutis.

The hydrogel would be an alternative to topical steroids.

I couldn't find any information online about the active ingredient in the hydrogel, "Atapro" or R047-26 in the NIH database. Atapro is a product of Oculus Innovative Sciences, Inc. It would seem to make sense for a company to keep the active ingredient confidential in the early stages--maybe they will need to modify its chemical structure and they don't want their competitors to know what they're working with. But on the other hand, I was easily able to find out the structure of some of Anacor's compounds which are in phase 2 trials.

More than anything, this report reveals how little I know about clinical trials. The study only included 17 subjects, and I'd expect half of them to be controls, so only 8 people were using the product. About seven of the subjects experienced a decrease in itchiness over the trial period. The study would seem to be on the small end of "phase 1," in which the main point is to screen for safety. But there was no explicit mention of what phase the trial might be.

The study details are behind a paywall so I can't find out whether the author had any conflicts of interest. All in all, rather mysterious!

Tuesday, September 25, 2012

Stress makes asthma, hay fever, eczema more likely

Higher stress levels make it more likely that an adult will develop asthma and hay fever, and are correlated with the presence of eczema, Danish scientists reported recently in the journal Allergy.

Stress has been shown to make the body's airways more sensitive to allergens, and intensify asthma symptoms. Similarly, it is generally known that stress can cause eczema flares--but the authors of this study wanted to show statistically that there was a link between stress and onset of atopic diseases in adults.

They drew on data from the Copenhagen City Heart Study, following 5648 adults in two assessments in 1981-83 and 1991-93 to see whether their self-reported stress levels at the first timepoint were correlated with the subjects developing asthma or hay fever in the interim.

Unfortunately the study's planners had neglected to have the subjects self-report eczema in 1981-83, so they just had information on eczema from 1991-93.

They found that subjects with "high," as compared to "low," self-reported stress had roughly doubled odds of developing asthma or hay fever.

Subjects with high stress had odds 75% higher of reporting eczema--although the authors do not mention that perhaps if you have eczema you are likely to feel more stressed.

However, the "atopic triad" of asthma, hay fever, and eczema tend to occur together in many people, so these findings are intriguing, and suggest that if you can reduce your stress by any means, you could also decrease your eczema symptoms--or never get it in the first place, if you are an adult who has risk factors such as relatives with eczema. I certainly know that if I am less stressed, my skin tends to be clear.

Friday, September 21, 2012

Hot pepper: the devil incarnate

After I eat food containing hot pepper, sweat beads my brow. Then, for a period lasting 30 minutes to a few hours later, I feel intensely itchy. I find cayenne is the worst--if I accidentally eat some during the day, I wake up scratching at night. But why?

In a recent post on the National Eczema Association website I explored allergy testing for eczema. Although onset is rapid, I wouldn't classify my reaction to hot pepper as an allergy. My symptoms are typical, except for the itchiness. And there is a well-known molecular explanation for how hot pepper gives you a burning, painful sensation, especially when you get some on your skin.

The active ingredient in pepper is a molecule called capsaicin. According to Wikipedia,
The burning and painful sensations associated with capsaicin result from its chemical interaction with sensory neurons. Capsaicin, as a member of the vanilloid family, binds to a receptor called the vanilloid receptor subtype 1 (VR1)... By binding to the VR1 receptor, the capsaicin molecule produces the same sensation that excessive heat or abrasive damage would cause, explaining why the spiciness of capsaicin is described as a burning sensation.

...Essentially, the body inflames tissues as if it has undergone a burn or abrasion and the resulting inflammation can cause tissue damage in cases of extreme exposure, as is the case for many substances that cause the body to trigger an inflammatory response.
I'd assume that when you eat hot pepper, you don't break down capsaicin; instead, most of it gets distributed all over your body, where it makes you feel hot, and triggers symptoms of inflammation. Great! The pepper-induced inflammation is likely generating signals in neurons that carry itch sensation to the brain.

But there's no explicit documentation of this in the scientific literature. When I searched for research connecting capsaicin and eczema on PubMed, the NIH archive, I found virtually nothing.

Instead, I was intrigued to discover on Wikipedia, PubMed, and the internet in general that capsaicin, far from being fingered as an evil trigger of eczema, is often touted as a TREATMENT for eczema. There are capsaicin-containing creams that you are supposed to rub on your skin to relieve itch. The theory, I guess, is that the burning pain overwhelms the itch neurons. I get that.

Unfortunately you're not supposed to rub capsaicin on open wounds. And with eczema, your skin always has open wounds. Even worse, the one clinical study I found showed that capsaicin cream relieved itch only for people who did not suffer from atopic dermatitis. Capsaicin appears to control itch that is caused by histamine; but chronic eczema itch is not caused by histamine, and so topical capsaicin does nothing for it.

In short, if you have eczema, hot pepper is not your friend, in any form. I love my hot sauce, but I can only look on it as a vice, not a virtue.

Monday, September 17, 2012

Go swimming. You can do it

I find that, even though I have eczema, I can go swimming regularly. Swimming is good for my back problems. But I can’t be as casual about it as I could if I didn’t have eczema.

First, I have to consider whether my skin is in good enough shape. Eczema, of course, can leave your skin open in many places. Perhaps you’ve seen those signs that say that people who have open sores are not allowed in the pool. Why not? Really, the main reason is that nobody else in the pool wants to get infected by a blood-borne disease such as hepatitis or AIDS. You can’t blame them—neither do I. And even though I am pretty sure I don’t have any such disease, I am not absolutely sure. But I am sure enough that it doesn’t bother me morally to get in the pool.

However, am I sure that nobody else who has swum in that pool over the last month, say, has hepatitis or AIDS? That is a sobering thought, especially in San Francisco, where AIDS first broke the news in the 1980s. It is to kill the microbes that cause such diseases that public pools are chlorinated. I believe I am not putting myself at great risk, but again, I am not absolutely sure. It doesn’t matter which day it is, I’m going to have some cracks in my skin. I get in the pool anyway.

But before I get in the pool, I cover my dry and torn patches with Aquaphor ointment. (Vaseline would do just as well.)

I’ve found that chlorine, and possibly the pH of the pool (slightly alkaline), can irritate my skin. Afterward, for at least half a day, my skin is subject to an intense itch that I don’t get if I don’t go swimming. To try to prevent this, I make sure to shower well. I do a particularly thorough rinsing of my eyes, which can become puffy and red otherwise.

Of course, once you shower, you have to moisturize. I find Aveeno Daily Moisturizing lotion from a pump bottle best for this. It’s a bit embarrassing to be slathering on moisturizer when you’re sitting on a bench in the locker room with two or three other guys dressing or undressing a few feet away. There’s some macho thing that makes you want to pretend that you don’t need any girly moisturizing—but, I suppose, this is where it’s a blessing to be in San Francisco, where a man can be as girly as he wants.

The strange thing is that I’ve found that swimming doesn’t seem to make my eczema worse. It could be that the chlorine, although it irritates, also kills off bad bacteria on my skin. In effect I am giving myself regular bleach baths, which doctors often recommend for eczema.

As far as being embarrassed about my skin goes--when you're swimming, you're underwater, so nobody can see you! The locker room can be a trial, but the facility I use is popular with a lot of wrinkly, hairy old men who, on the whole, make me look like Brad Pitt. Who, as I read in a gossip mag, happens to have eczema.

Tuesday, September 4, 2012

New NEA blog post on allergy tests for eczema

I just wrote a new post on the NEA blog, about food allergy tests for eczema. I interviewed Jon Hanifin, a professor at Oregon Health Sciences University and one of the giants in the field of eczema research and practice. (Eczema is commonly diagnosed using the "Hanifin and Rajka" criteria.) Read the post if you are wondering how useful allergy tests are for food triggers of eczema.

The last few weeks my family has been under a lot of stress because my five-year-old son just started kindergarten. He has been unhappy about moving to a new school--where he's in a class of 28 (his preschool had 14 kids) and about 500 students attend total. He cries when we drop him off, when we mention school, and at night when he protests that he doesn't want to go. Plus there's homework--four pages a day, for a kindergartner! and Dad's Club and PTA. So you can understand why my posts have been a bit sparse. The pace will pick up again, I'm sure.