Dermatomyositis

Without beating to death the difference between polymyositis and dermatomyositis, suffice it to say polymyositis is the disease without skin manifestations, whereas DM does have skin changes.

The skin changes associated with DM are as follows:

1. Gottron's Papules (see above).  Violaceous papulosquamous eruptions over the MCPJs and IPJs.  

2. Heliotrope rash.  The classic violaceous rash on the eyelids is textbook, but it may be subtle at times.

3. Shawl Sign.  Diffuse, flat erythematous rash over back, neck, upper chest (often in a V shape)

4. Facial erythema

5. Periungual telangiectases

6. Flagellate truncal erythema

Not skin, but still part of the diagnostic picture:

7. Proximal muscle weakness (ask them to stand up out of a chair without using their hands)

8. Muscle tenderness, particularly the proximal thighs.

Just like with Beau's lines, the best place to find DM periungual telangiectases is the fourth finger.  

Although this is a discussion about adult DM, there is a juvenile variant which also has cutaneous calcifications.

Systemic Lupus Erythematosus

SLE is a pretty strange disease.  It manifests itself as a photosensitivity in many cases, and can be thought of as an allergy to the sun with protean medical manifestations.  When one looks at the patients (mostly women) who have the butterfly rash, what we look for is such subtle signs as whether or not the nasolabial fold is spared, the submentum is less involved than the chin, and, if there is a hand rash, whether or not the rash spares the knuckles.  If it does, slide all your chips onto the "SLE" spot on the table, and expect to cash in.  

In contradistinction to dermatomyositis, (see the next post) even though there is periungual erythema and perhaps telangiectasia, the sparing of the MCPJs and the PIPJs is classic SLE, whereas with DM one would expect it to involve the knuckles, the so-called Gottron's papules.

Why couldn't this be SCLE??   Well, it could, but SLE is a far better answer given the photo, because there really isn't a papulosquamous look to this at all, but more just that inflammatory look.  Remember, when faced with a choice, pull the trigger on the MOST likely of the dxes.

One last point to make.  Obviously, this is a systemic disease (or they would  have named it something else, wouldn't they?) but one of the main systems it affects that most people forget is the brain.  When their antibody titers are cranked up and they are really sick, they get a cerebritis which can make them loopy, unpleasant or, in rare cases, quasi-psychotic.  So, forgive them if they are flaring and are cranky with you.  They probably don't mean what they say.

Your job, above all else, is to get them to stay out of the sun.  Yell at them if they disobey you.  Hurt their feelings if necessary, because with each flare they get, they can further damage their kidneys, joints, etc. and those don't recover from the damage.

Neurofibromatosis Type 1

This very unfortunate woman has Von Recklinghausen's Disease, aka NF-1.  Despite the obvious neurofibromas (which buttonhole, as you remember) we also see axillary freckling/pigmentation, which we know as Crowe's Sign.  We should also examine the eyes, and would expect to see Lisch Nodules;  we would also expect to see cafe au lait patches (6 or more).  We could image them, looking for optic gliomas and would also expect a family member to have the disease (as it is inherited as an autosomal dominant disease), as well, although 50% of cases are spontaneous, i.e. not inherited.  

Chronic Paronychia

Chronic paronychia is a condition that results in nail dystrophy that usually extends across the entire breadth of the involved nail.  It is caused when there is disruption of the proximal nail fold/ cuticle resulting in a space under the free edge of the nail fold, which creates a chronic wet area which is an ideal environment for yeast, often of the candidal persuasion. 

The way to distinguish this from, say, Beau’s lines is to look at the proximal nail fold/ cuticle unit to see if it is intact.  Next, look at the character of the transverse grooves.  If they are irregular and kind of ragged looking, it is usually a result of chronic paronychia.  If, on the other hand, it is a smooth, even curvilinear line across the nail plate, it is usually a Beau’s line.  Remember:  Beau’s lines are a result of a physiologic stress of one sort or another; it is a reflection of a systemic issue, not a local one.  It is the same process (slowing of the growth of the matrix) which in the hair also leads to telogen effluvium.  In fact, if I am trying to work someone up for telogen effluvium, the first thing I do is look at their nails. The best place to find Beau’s lines is the fourth (ring) fingernail for reasons that are completely unclear to me, but chronic paronychia can be on any nail. 

The reason I put this picture in is because chronic paronychia was discussed in the blog a couple of days ago under habit tic deformity.  NOBODY should have missed this question!!

Metastatic Melanoma to the Scalp

When looking at lumps and bumps on the skin, the first algorithm we go through is “benign or malignant?”  There are usually multiple clues.  First, history. Of course, I didn’t give you the history on this one, because it would give away the answer (he was being treated for metastatic melanoma). Second, the character of the lesion.  As we all know, cancers grow as fast as the body will let them, but they are all marked by a relatively high metabolic rate compared to the surrounding tissue (even the lowly basal cell carcinoma induces blood vessel formation, just so it can be fed).  High metabolism demands a good blood supply, so most cancers, if they are going to be successful, will be surrounded in some way with an increased blood supply.  Third, what is the context, exam-wise?  We see here numerous other nodules on the scalp, which would make us think “Hmmm.  Multiple vascular lesions on the scalp.  Unlikely to be a primary cancer.”

So, run the algorithm.  Benign versus malignant.  Primary versus metastatic.  And the metastases seem to like skin.  Although many metastases like the skin, the ones that stick out in my head are clear cell carcinoma of the kidney and melanoma.  So, since there is no pigment in the lesions, I would have guessed metastatic clear cell ca, but nevertheless a metastatic process.  I would biopsy with a scoop shave, and let the pathologist sort it out with immunohistochemical studies.

Why metastasize to the scalp?  Well, the scalp, much like the lungs, and the liver, sees a lot of blood go through it, and it has multiple small vessels in it.  If a metastasis is floating around in the bloodstream, having arrived (usually) through the lymphatics, getting dumped into the subclavians via the thoracic duct and into the general circulation.  They then float around until they get wedged into a small vessel, where, if they have enough nutrition, they set up shop.  They secrete cytokines which cause local proliferation of blood vessels, which allows the metastases to grow.  In some cases, the growth is explosive, and in others, it is not. 

Many patients are a little reticent to have their picture taken, especially when they are faced with serious consequences of disease or with a disfiguring condition.  This gentleman wanted  me to take his picture, so other people would be warned about melanoma and hopefully avoid the pain he endured.  He passed away roughly a week after this picture was taken, from brain and lung metastases.  

  

Habit tic deformity

The habit tic deformity is a self-induced condition that is caused by damage to the external part of the nail matrix, usually by pressing or scraping on the lunula of the nail with another fingernail.  Since the matrix is softer than the fully-formed nail, it is more easily damaged than the distal nail.  The way to tell it is a habit tic deformity is to see if the dystrophic changes extend all the way across the nail, as they would with chronic paronychia, or if they are longitudinal and well defined, like it would be with a median canaliform dystrophy.  Also, with chronic paronychia, one would see interruption or complete disruption of the proximal nail fold.  

Median canaliform dystrophy

Use this as a moment to reflect on the way the nail is made.  The lunula, which is largely obscured by the proximal nail fold, is the matrix.  The most proximal of the lunula/matrix ends up being the outer part of the nail plate, the distal part of the lunula/matrix is the deep part of the nail plate.  So, since this dude was primarily picking at the distal part, the changes of the dystrophy actually go all the way through the nail.  To compare it to the rainbow below, the red part is originated at the proximal matrix, the violet part is formed at the distal part of the matrix.

We are coming down to the final days of March Madness, and we have a two-way tie for the lead, with two others one point behind.  Who will win the Gewurztraminer?  Stay tuned...

The Best Damn Band in the Land

The Ohio State University is not my alma mater (Miami of Ohio is), and I never played a band instrument in my life, but growing up in Columbus, listening to the Ohio State Marching Band play Fight on Down the Field, or watching them do "Script Ohio" are two of the goofy pleasures of my life.  Growing up in Columbus and being an OSU fan is much like growing up in Dublin, Ireland.  Almost everyone in Dublin is Roman Catholic, and almost everyone in Columbus can give you a blow-by-blow account of the last OSU-Michigan game.  It's religion, sort of.  

When my son, who did play saxophone in the University of Florida's marching band, went with the Gators to the BCS National Championship game versus OSU, his comment was this:  "We beat them in football" (I don't want to talk about that)"but, they were the best marching band I ever saw." Well said, Danny Boy.  Well said.