Erythema Multiforme (minor)

Erythema MultiformeI got a slide of my skin biopsy from the erythema multiforme (minor) that developed after chiggers and weird immune reactions.  The images below are actual skin biopsies and pictures that I took myself. The biopsies are stained with H&E (haematoxylin & eosin), which colour the cytoplasm of cells pink and the nuclei of cells purple (or dark blue).  Both images were taken at the same magnification (100X).  Note that the skin on the left (the normal skin) is NOT mine, but was a recent slide from an experiment where I work.  You can see differences between the two pictures that are obvious, and I’ll start from the outer surface.  First, note that both have a netlike mesh on top of the skin.  That’s the outer stratum corneum, a protective layer.  Mine is thicker, and there may be two reasons for that: the normal skin came from a different area of the body, and there’s probably an age difference (and I’m likely younger).  Under that layer is a thick purple band that has fingerlike projections—that purple region is the epidermis.  It’s normal for it to be purple.  Again, mine is thicker, probably due to physical location and age.  All the pinkish stuff is dermis.  The normal skin has a few scattered dark spots-nuclei of cells-scattered here and there, but my skin sample has TONS of very dark cells.  That’s the abnormal part.  Those are white blood cells—in particular, they’re probably T cells, though you can’t tell that much just by looking at them.  You should also note that they form distinct regions that tend to have rounded edges: that comes from blood vessels.  These are perivascular leukocytes (white blood cells).  There was a difference in opinion on the formal, official diagnosis: one dermatopathologist says classic erythema multiforme, the other says not (just unknown perivascular leucocytic inflammation).  The gist of it is that you can SEE all the cells that are not normally there that were trying to destroy my (otherwise intact) skin!  Kinda neat.  I liked getting a microscope slide of my own skin.  But then, I’ve never been normal…

Immune Reactions

So after the chigger bites post, I should have posted this.  A couple weeks after the chigger bites, my hands broke out in what appeared to be a rash for what appeared to be no good reason.  I hadn’t come in contact with any new bugs, didn’t have any existing bugs, and it didn’t seem to be from touching something (contact-mediated dermatitis).

Options for what-the-HELL were going on included: allergic reaction to (????), scabies (ewwww), bug bites (other), fungal infection, bacterial infection, parasitic infection, rare and weird complications (my boss helped some there, with ID reactions).  I sprayed for bugs (fleas, bedbugs, scabies, etc.) and saturated my living space with toxic loveliness. I tried Neosporin.  I tried metrogel, cyclosporin, clotrimidazole, hydrocortisone, and fluocinonide.  And aloe, oatmeal, and caladryl.  Nothing worked or helped.  Having thus ruled out the obvious, what was left was most likely an allergy to… something.

I went to the doctor and was diagnosed with a rash.  That was terribly helpful. The general consensus, though, was that my immune system went a little haywire over the chigger bites (see previous) and was refusing to calm down.  This means a round of steroids (prednisone). Based on what was going on and what it looked like THEN, aggressive was preferred.  For the first two days, the symptoms started to recede, but then they came back with a vengeance.  This is not quite the ugliest picture I could have taken…. it’s hard to take a picture of your own hand with a cameraphone, by the way.  And it was 4 days before the worst of it.

Erythema Multiforme

My fingers blistered and swelled so much I couldn’t bend them. And, of course, ITCHED.  I started thinking about amputating my hands.  My backup plan was a bottle of nitric acid.  I went back to the doctor, who referred me out to another dermatologist (yes, I work for one; he was out of town).  I was diagnosed with erythema multiforme (minor), and again, more prednisone.  At this point my blood pressure was over 160/104 and shows no signs of coming back to the land of non-aneurism…. more steroids sounded great (to relieve symptoms) and not-so-great (side effects).  The side effects have been rough.  You can Google erythema multiforme (EM) for more pictures (ewww) and information, but I thought I’d offer a qualified summary.

EM is generally considered a Type IV hypersensitivity, also called a delayed-type hypersensitivity.  It looks like bulls-eye targets on your skin, though these can overlap so much that they’re hard to recognise (mine did).  It can also affect your mucous membranes (nose, mouth, throat) and eyes.  This type of allergy is different from the a type I (anaphylactic) reaction and isn’t controllable with “allergy meds” like Allegra, Zyrtec, or Benadryl, though these can help with some of the incidental symptoms.  An allergy occurs when your immune system recognises and attempts to destroy a foreign invader (that can’t really hurt you) like pollen, animal dander, something about your laundry detergent.  It usually does damage to surrounding cells at the same time.  EM is a sign that your immune system is, essentially, completely insane and destroying some harmless substance: your SKIN.  It really shouldn’t be attacking you at all (that’s supposed to be trained in the thymus).  But it does.  It’s not caused by the same kinds of cells that make an anaphylactic reaction (like hives/urticaria, or throat-swelling-shut reactions).  Instead, these are highly trained T cells that are… bored?  We don’t understand erythema multiforme well.  There are also indications that it might be related to herpes infections. 

So how do you treat it?  You have to get the immune system to CALM DOWN.  That means, partially, that you also have to calm down… which is easier said than done when you ITCH. I’ve also determined that I would rather break a bone than ITCH that badly.  To calm down the immune system, prednisone is often used.  Hey, it’s cheap and effective.  Now what’s really odd about this is that it’s a lot like your body’s own stress hormones: cortisone.  You’re just using SO MUCH prednisone that your body could never get to that level, and it temporarily forces a shutdown of the system—including your hyperreactive immune cells.  As you gradually decrease the dose, things should go back to normal (once you get the problem under control).  It’s a risky treatment, because you are suppressing your immune system: meaning colds and flu and everything just became a lot more challenging to fight off.  You also have to avoid some other medications (aspirin) and have weird food cravings, high blood pressure, increased risks of glaucoma and lots of other drawbacks—but these are generally temporary and go away once you stop taking the medication.  For short-term treatment, it shouldn’t cause lasting damage.  A couple of weeks of high blood pressure, mood swings, and chocolate cravings are likely better than losing your hands or going blind.

Other suggestions?  I wore a pair of black elbow-length gloves for a couple of days.  Keeping it hidden also helped me—not seeing it meant I didn’t obsess about it quite as much. The sensation from the gloves was at least consistent, and so easier to ignore than transient sensations that caused insane itch.  I got to make Lady Gaga jokes.  People weren’t as scared of me.  I couldn’t scratch effectively.  All good things.

Will it come back?  That depends on whether I get devoured by chiggers again… that might not have been the trigger, but it’s the most plausible.  I’m not actually going to worry about that unless I have to worry about that… I don’t think it’s likely, in this case.