"This bodes some strange eruption..."

Apr 06 2011 Published by under Medical Musings, Medicine

So that rash isn't anything horrid apparently.  My dermatologist, who is wonderful, described it as a mixture of eczema and very dry skin (sort of a mix of eczema craquelé, atopic dermatitis, and xerosis).  She advised less frequent lukewarm showers, good moisturizer, and a high-potency steroid cream.  Hopefully, the change in weather will allow us to get some humidity into the house, but the shower thing is a problem.  I work in small rooms with sick people, so I shower once in the morning to avoid offense in the exam room, and once in the evening to avoid contagion at home.  The doctor recommended a week in Florida, but that's not on the agenda.  The steroids should do it though, eczema being one of those diseases where the immune system is a bit irrationally exuberant.

Antibody molecule

Speaking of immunologic illnesses, I was confronted last weekend by an annoying case of common variable immune deficiency (CVID).  The primary problem in CVID is a failure to make sufficient quantities of antibodies, the chemicals that mark biologic invaders for destruction.  Antibodies are part of the adaptive arm of the immune system that recognizes specific invaders.  The immune system also has a passive arm that can respond to molecules that look generally like invaders.  Antibodies though are very specific.  One may recognize a particular surface molecule on a staph bacterium, another an influenza virus.

The arms of the "Y" on the immunoglobulin molecule are the end that bind to antigens (molecules that form parts of various bacteria, viruses, and other invaders) and can bind very specifically, like a lock and key.  Given the millions of foreign molecules we are exposed to, many of which are harmless, how can we possibly maintain a library of antibodies against invaders?

The immune system, specifically a type of white blood cell called a "B-cell", creates antibodies whose structures are random.  Not every one of these will bind pathogens.  During development of immune cells, this part of the immune system is very closely regulated, so that immune cells that recognize "self" molecules are turned off.  This culls out cells that would attack us, and (normally) leaves the ones we need to patrol for invaders.  If an antibody happens to find an antigen that fits, it will bind, setting off a cascade of changes which will ultimately lead to production of more of that antibody.  This way, a large repertoire of potentially useful antibodies are created, but only the ones that are needed are produced.

As a wise physician once told me, "antibiotics never cured anyone," meaning that antibiotics generally help our own immune system gain control of an infection.  In CVID, antibody production is impaired, so when the patient becomes ill, antibiotics may not be sufficient to save them.  While penicillin may inhibit bacterial cell wall synthesis, antibodies can not only mark bacteria for destruction, but send out a chemical signal to call in more immune cells, evening the odds.

Patients with CVID often become much more ill from common infections that patients with normal immune systems.  Since these patients cannot make enough of their own antibodies, one possible treatment is to give them antibodies from someone else.   Since the antibodies are floating around in the plasma, perhaps we could simply give the patient a plasma transfusion.  The problem here is that any single donor may not happen to have the specific antibodies needed.  If, for example, my CVID patient had an infection with Streptococcus pneumoniae serotype 7F, but the donor had never been exposed to that and therefore did not have antibodies, the plasma would not be helpful.  The solution is to take plasma from thousands of donors, pool it, and divide it up so that each unit will have a wide variety of antibodies.  This is remarkably effective.

So as I spend my precious minutes under the lukewarm shower, I'll contemplate the wonder that is the immune system, and the hard work that has gone into giving us the ability to manipulate it, allowing me to scratch less, and preventing another patient from dying of a normally curable disease.


14 responses so far

  • D. C. Sessions says:

    Ah, dry skin. Welcome to getting older.

    Per my PCP a couple of years ago (and it seems to work): cut back on the soap. It's not necessary to degrease every square mm every shower. For instance, a water rinse in the evening with soap for the public-contact areas can save a lot of irritation.

    That and buying moisturizing cream at Costco. Like many men, I was always resistant to using creams and lotions. A chronically dry back cured me of that bias. Now I get "greased up" by $HERSELF daily.

  • Wyndemir says:

    I'm prone to eczema around my neck, I hate to imagine how it would feel all over. I'm getting itchy just thinking about it. Aveeno has a new moisturizer for eczema, and personally, I've found it to be the single best thing short of steroids to use when it starts acting up.

  • leigh says:

    might i suggest a humidifier in the bedroom- if not a bigger one for the whole house. while plunking down $80 is nothing to sneeze at, the high-capacity humidifier is probably the best dollar-for-dollar investment we've made this winter when it comes to skin comfort.

  • BB says:

    Echo Leigh, humidify the air at home. Your lungs will thank you too. We have a whole-house humidifier. $1500 well-spent. I no longer get bronchitis/pneumonia every year.
    And use very mild cleansers like Aquanil or Cetaphil - no deodorant soaps. And apply humectant moisturizers like Aquaphor over damp skin. Can you tell I've been there, done that?
    BB, immunologist by training

  • markincleveland says:

    Family practice, allergists, oncologist and and any other physician who does not additional specific immunology training have no business treating patients with a PIDD.

    The permanent damage that has been done to these patients while physician's try to learn it as they go along is incredible . . and very sad.

    Refer them to a major medical center who has an expert immunologist who treats a large population of immune patients, even if they have to travel to get there,

    Have that doc develop a treatment plan had have the patient get their infusions and follow up medical care with you at home and just let the expert be the "quarterback" of the team.

    I know it is difficult to say you don't know everything . .but these are complex illness with lot of very strange complications and need to be assessed by an expert.

    At the very least, ask the Immune Deficiency Foundation for a free expert consultation with a top line immunologist. It is a free service they offer.

    • PalMD says:

      Thanks for the unsolicited advice. The treating physician is a locally and nationally recognized leader in the field.

  • Mary P says:

    My favorite trick to increase household humidity is to hang the laundry in the house instead of using the dryer. I also use a hygrometer to keep track of how dry it is getting - lack of humidity is more of a problem than too much in my house.

  • Dr. Dredd says:

    You mean your boss won't accept "My doctor told me I need a week's vacation in Florida" as an excuse? 🙂

  • daedalus2u says:

    If you use a humidifier, don't use an ultrasonic one. They turn all the dissolved solids and bacteria in the water into inhalable aerosols.

  • a little night musing says:

    A lovely and informative post, riffing off your horrible rash. (Or not-so-horrible, hopefully!) I just want to say how much I enjoy your writing and what I learn from it, since I don't say it enough.

  • PalMD says:

    thanks much. Don't mind some positive feedback.

  • OleanderTea says:

    First winter in New England (after moving from Florida), I developed the truly awful dry-skin/eczema mix you describe, the likes of which have been unseen on me since I was 7 (which was when we moved to Florida).

    Two winters and a bunch of attempted treatments later, I can say what worked for me: humidifier in the house; taking short, lukewarm showers (I get my heat fix by letting the bathroom steam up); only using soap on the bits of the body that tend to smell; shaving using Aveeno bath and shower oil; using vats of Curel and Aveeno anti-itch moisturizers; using as directed the high-potentcy steroid from my dermatologist; washing and drying clothes in perfume-free products; and if possible, going home to FL for a week in January (though next year, I think I'm going to Mexico or the Bahamas or someplace fun).

    This winter, a coin-sized spot on my thumb was all I got...until a week ago, when pollen from a new houseplant caused my face to break out in eczema. Ewww.

    I wish you much luck on getting rid of the miserable rash.

    [mom] And stop scratching! You'll get impetigo! [/mom]

  • Necromancer says:

    Sounds like lyme disease. Probably turned chronic at this point. Not to worry though, its easy to cure with one single dose of doxycycline and you'll be fit as a fiddle.

  • [...] &#83pecificity of &#97ntibodie&#115 &#97&#115 exp&#108&#97ined by P&#97&#108MD: http://scientopi&#97.org/b&#108ogs/&#119hiteco&#97tunderground/2011/04/06/this-bodes-some-str&#97nge... “Antib&#111&#100ie&#115 &#97&#114e p&#97&#114t &#111f the &#97d&#97ptive &#97&#114m &#111f [...]