TILIR #18: Ota, Ito, and blue milk

Blue flour-water
from Wikipedia

TIL: Nevus of Ota and nevus of Ito are two lesser know types of dermal melanocytosis, or gray-blue patches of skin. The more common form is the gray birthmark often found on the lower back or butt called congenital dermal melanocytosis, but more commonly known as Mongolian spots. The medical field is trying to shy away from this latter terminology... in case it offends Mongolians? It's not good or bad so not sure why it would offend. I think it might be more that the name is just arbitrary and inaccurate, with the condition having nothing to do with Mongolia or its people.

Anyways, nevi of Ota and Ito are gray-blue patched of skin in the distribution of the first/second branches of the trigeminal nerve (top half of the face) and the posterior supraclavicular and lateral brachiocutaneous nerves (neck, upper arm, upper back).

The Tyndall effect is what gives these lesions a bluish hue. This is the same effect that gives rise to blue eyes and turns milk with flour in it blue. In the milk, flour particles scatter light with the energetic blue light preferentially scattering over the red wavelengths.

In both eye color and the above skin lesions, the flour-like light-scattering particle is melanin, the dark pigment that colors skin. The bluish gray skin color with any of the dermal melanocytoses happens just like the blue milk, with melanin scattering the blue light and absorbing the red. Eye color is far more interesting. Irides with lots of melanin absorb almost all the light coming in because any blue scattered light from all but the surface-most layers of the iris just get caught by the melanin in front of it when trying to bounce out. These eyes tend to look dark brown.

Iris color diagram (made by me!)

The less melanin in the iris, the more blue light is able to escape back out of the eye after scattering. Bright blue eyes have the perfect goldilocks amount of melanin to scatter light but not get in its own way. Greens and hazels are somewhere in between. Albino persons have no melanin in their iris and so neither absorb nor scatter light coming in. The iris is basically see-through so the red of the retina behind can shine through giving the appearance of red eyes.

WILTIMS #427: IM didactic day #2

Today was a fairly dry day of lectures back up at campus (check out yesterday's post for a week's worth of juicier clinical fare). We started with dermatology, then a miserable lecture on HIV, some antibiotic practice and EKG interpretation. After a far too brief lunch, we came back for a stuffy lecture on congestive heart failure by our stuffy chairman of medicine and then we ended with a lecture on palliative care and pain management.

TIL: Urticaria pigmentosa, or maculopapular cutaneous mastocytosis, is a weird condition where mast cells accumulate in blobs on the skin. These immune cells release histamine, one of the chemicals that makes you itchy. So if you poke one of these spots on their skin, within a few minutes a big itchy red wheal will form.

Derm lightning round!

• nummular: round; as in nummus, Latin for "coin"
• arciform: arc forms
• serpiginous: snake-like
• ichthyotic: fish-scale-esque
• koebnerization: spreading a lesion by patient interaction (e.g. a rash that spreads to the areas you scratch)

Ways to be wrong 95% of the time, but scary-awesome the other 5%: If someone has a rash around their mouth, ask if they like to eat mangos. If no, then delicately ask if they suck their thumb. Both of these are reasonably common explanations for a perioral rash and you'll look like a mind reader if you call out a(n unknowingly allergic) mango enthusiast or adult thumb-sucker.

WILTIMS #361-3: Outpatient round-up and peds wrap-up

Another clerkship comes to an end! Yesterday was my last day of clinical work on the pediatrics rotation. There's a study day today, a shelf exam on friday, and day-1 of OB/GYN on Monday. No rest for the wicked ...ly awesome?

The past three days were my "week" on outpatient pediatrics. Our hospital offers two types of outpatient experiences; there is a clinic at the hospital I've been working at and there are various pediatricians' offices around the county. I did my time in an office in Yonkers with an amazing pediatrician who somehow tried to tutor my classmate and I in the entirety of pediatric medicine in the three days he had with us. While trying to soak up the onslaught of knowledge I needed to wring out my brain every night and blogging went by the wayside. But below are some of the more interesting factoids.

MondayIL: A pilonidal cyst is a boil that forms on the tailbone. Usually it can be treated with antibiotics but if the infection gets too severe, a small surgical procedure can be done to drain the abscess.

TuesdayIL: If a baby turns blue after birth but turns pink again when crying, they probably have choanal atresia, the congenital blockage of the back of the nose. Normally, babies breath exclusively through their nose, but when they cry, they have to breath through their mouth. If the nose is blocked, they turn blue from essentially not breathing.

WednesdayIL: If a week-old vaginally-delivered baby has red, inflamed eyes and a cough... they probably have chlamydia. Yes, that chlamydia. Amusingly, while that may seem like a stretch at first, I'm sure any classmates of mine reading this are like, "Well, obviously." Every baby born in a US hospital gets a prophylactic dose of erythromycin squirted in their eyes right after birth. The reason for this is that chlamydia and gonorrhea are quite widespread and can transfer from the mom's birth canal to the baby's eyes during birth. In babies, the main complication of a chlamydia infection is a mild pneumonia or bronchitis.

WILTIMS #293-5: Oranges, derm and a belly brain cancer

WednesdayIL: An inflamed breast is obviously never someone's idea of a fun time, but in rare cases, it's far worse. The inflammation is usually caused by a bacterial infection, especially during periods where the woman is breast feeding. Unfortunately, the same appearance of inflammation can also be caused by inflammatory breast cancer. This variant of malignant breast cancer is caused by the tumor blocking off the lymphatic drainage from the breast and has a very poor prognosis. If the inflammation progresses far enough, it can cause a peau d'orange or "orange peel" appearance where the breast turns reddish-orange and develops dimples as the swelling tissue pushes out past the hair follicles. I'll let you google that picture on your own.

Thursday: Today was our last gross specimen lab of the year, and we were looking at gynecological pathology. Most of the samples were ovarian and uterine tumors, fairly repetitive over-all. One specimen, however, managed to wake up even the most tuned-out of my classmates. An invasive placenta had grown into the uterine wall, requiring a total hysterectomy - removing the uterus, ovaries, and a 14-week fetus.

Now, we've passed around kidneys the size of a watermelons, lungs as black as coal, and brains of infants, but I've never seen everyone snap to attention as quickly as when we noticed that fetus lying on its side in a pool of preservative in the specimen bin. For me, it re-humanized an already desensitized procedure of looking at bits of dead people. We take for granted that these people lost their organs, and usually their lives, after some valiant but futile effort by our medical colleagues. That's enough to put our minds at ease. But this case provided too much information for us to remain detached. This woman probably went in for a pregnancy check-up and found out that not only would she lose the baby, but with the removal of her reproductive organs, she'd lose the ability to ever try again. Not quite as fun as poking squishy things normally is.

ThursdayIL: A chloasma or melasma is a facial pigmentation change that is associated with pregnancy, hormonal birth control and hormone replacement therapy.

You can develop primary brain cancer (or any cancer, really) from a teratoma. A teratoma, literally "monster-tumor," is a germ cell mass that can grow into any kind of tissue thanks to the undifferentiated nature of its precursor cell type. These tumors are well known for containing fat, hair, lung, bone and teeth, all mushed together at some mid-line place in the body (for embryologic reasons). Teratomas are almost always benign, but any of the tissues within the tumor can, on rare occasions, become cancerous themselves. So, if you're really, really, really unlucky, you can get brain cancer in your teratoma in your uterus. (This story was confirmed by a pathology resident to have actually happened at our hospital in recent years)

TIL: Dermatology lightning round!

Macule: flat, non-palpable lesion less than 1 cm

Patch: same as macule, but >1cm (e.g. café au lait spots)

Papule: raised lesion less than 1cm (e.g. pimples)

Plaque: superficial raised lesion >1cm (e.g. psoriasis)

Nodule: deep/solid raised lesion >1cm

Vesicle: fluid filled less than 1cm (e.g. poison oak/ivy)

Bulla: same as vesicle, but >1cm

Pustule: pus filled lesion of any size

Wheal: firm raised edematous (swollen/red) lesion (e.g. hives)

WILTIMS #184: It's actually lupus!

Apparently, today is one of two days during our preclinical years that we are taught by the dermatology department. In case you are somehow unfamiliar with the weird place that dermatology holds in the medical specialty hierarchy, the head of dermatology had this to say about training in that specialty: "Dermatology is very hard to get into, but your life is very easy after that." [everyone laughs], not at his message, but at his candor.

When you ask the average person what the most prestigious medical specialty is, you are likely to hear some impressive sounding area of medicine like neurosurgery. Dermatology is, in fact, the most competitive and highest paid specialty. Though poking at people's rashes and scraping away moles might not seem like the most desirable work, the lifestyle, hours, and pay have made it, far and away, the most hotly contested field to enter every year.

One of the weird flukes of this arrangement is that, though most would admit one doesn't need to be the top of one's class in med school to treat diseases of the skin, only the most intelligent and talented graduates become dermatologists. This trend was driven home again for me today in a small group session where my module was taught by the senior dermatology resident at our hospital. She was quite the imposing and intelligent instructor. Though only a few years older than us, she was easily an expert on today's topics and absentmindedly bossed around our normally high-and-mighty physician instructor.

TIL: Hemophiliacs are like summer squashes... Stick with me on this one. You know how each individual squash can look dramatically different in size, shape and color from one another regardless of the seed from which it grown? The way they can modify their appearance, even with the same DNA is through epigenetics. Epigenetics is the suppression or augmentation of genetic information through processes like methylation and X-inactivation. This is the same mechanism that diseases like hemophilia use to present with completely different symptoms and severity between directly related family members.

IT'S NEVER LUPUS (at least on House MD)! Ever wonder why lupus is always in the differential diagnosis for the patients on House, even though it almost comedically was never actually lupus causing the symptoms? The reason for this is that lupus has very broad, variable diagnostic criteria. It only requires 4 of the following 11 symptoms to diagnose lupus, often remembered by the mnemonic 

DOPAMINE RASH:

Discoid rash
Oral ulcer
Photosensitivity
Arthritis
Malar rash
Immunologic criterias
Neurological symptoms-(lupus cerebritis)
Elevated ESR
Renal disease
ANA+ve
Serositis
Hematological abnormality