Thursday, June 28, 2012

Condyloma Lata

The phenomenon known as the Prozone Effect occurs when the antibody titer of a patient with syphilis is so high that it overwhelms the ability of the RPR test to detect it.  It particularly occurs during pregnancy, with HIV infection and in rip-roaring cases of secondary syphilis.  

Condyloma lata are notably different from condyloma acuminata by being softer- MUCH softer- than condyloma acuminata, and by being usually broader and flatter than condyloma acuminata.  They are commonly patches as well as papules.  Their corresponding lesions on the mucous membranes are called, surprisingly, mucous patches.  They have the same spongy appearance as their perigenital counterparts.  

The whole reason for asking this question is to call attention to the soft nature of the condyloma lata, and to call attention to the Prozone Effect.

As an addendum, consider ordering an  FTA-ABS for those patients who you think might be false-negative RPRs.  

Wednesday, June 27, 2012

Lymphogranuloma Venereum

This week’s theme seems to be “Looking for love in all the wrong places”. LGV is a sexually transmitted disease that is caused by Chlamydia trachomatis, which is related to the causative agent that which causes, among other things, trachoma, an eye infection common in parts of Africa.  The serovariants that cause LGV, however, are distinct from the ocular variants and are transmitted sexually instead of by close contact.  The first signs of LGV are usually a painless ulcer on the external genitalia, followed by painful lymphadenopathy, which often leads to draining abscesses.  These buboes, in combination with the history, are pretty much suggestive of LGV.  While in the early part of the lymphadenopathic stage, you see swelling on both sides of the inguinal ligament, which leads to the clinical picture we see above, which is known as the “Groove Sign”.  While not pathognomonic (patients with lymphoma and  other infections can have a faux Groove Sign) it is highly indicative of LGV, and the Pavlovian response you should always have when faced with such a clinical picture is to immediately utter “LGV” under your breath.

Tuesday, June 26, 2012

Gummatous (Tertiary) Syphilis

Ah, syphilis.  The disease that gave our specialty its foothold in modern medical consciousness, it was known variably as the Great Imitator, the Great Pox (as opposed to smallpox) and, depending on which side of the Channel you lived, either the English Disease or the French Disease.  Me?  I have both English and French friends, none of whom have had syphilis - to my knowledge- and so I must remain neutral.

Syphilis comes in four flavors:  Primary, Secondary, Latent and Tertiary.  A full discussion of the timing of these manifestations is available online, and so I won't belabor the subject, but in the case of tertiary syphilis, it tends to occur somewhere around fifteen years later, give or take.  

Gummatous syphilis is one of the tertiary manifestations of this spirochetal conundrum, as is neurosyphilis and cardiovascular syphilis.  The gummas often presented on non-skin tissue and were soft, granulomatous masses.  In the skin, they commonly became ulcerated as above.  The lesions started out as painless, progressed to mild tenderness but often then led to a gnawing, boring pain that was excruciating.  

Syphilis had a great hold on the 19th and early twentieth century mind.  Henrik Ibsen, Norway's most famous playwright, wrote a play Ghosts, about dysfunctional Norwegian society, with syphilis playing an allegorical role representing the moral rot of society.  Needless to say, it was quickly banned just about everywhere, thus cementing Norway's place as the Graveyard of Playwrights.

We will see syphilis again, because of its importance both in medicine and in medical history.  

Sunday, June 24, 2012

Harlequin Ichthyosis

Harlequin Ichthyosis is the most dramatic of the congenital ichthyoses.  At birth, the infants display a profound thickening of the skin and as a result are encased in a massive thickened shell of abnormal skin.  They also have contractions of the eyes, mouth, limbs and have an abnormal barrier function, leading to fluid shifts, metabolic abnormalities and susceptibility to infections.  Those of you who have children should thank your maker every day your child does not suffer from this condition.

It, like many of the ichthyoses, is an autosomal recessive condition, and the specific genetic abnormality is ABCA12 on chromosome 2.  They have ultrastructural abnormalities related to the formation of and maturation of keratin.  Although this was at one time always fatal, with the advent of treatment  with systemic retinoids there are multiple reported survivors.  

As a bonus question, clinically how could you differentiate between lamellar ichthyosis and harlequin ichthyosis?

Thursday, June 21, 2012

Transient Neonatal Pustular Melanosis

TNPM is a condition marked by pustules and vesicles that are present at birth, and which heal with a collarette of scale and, eventually, a hyperpigmented macule.  It is fairly common in African American children, and is remarkable in that the pustules are loaded with neutrophils.  It differs from Erythema Toxicum Neonatorum in that it is present at birth (ETN usually has its onset after birth), has a relatively normal background (ETN has an erythematous background) and by the predominance of neuts on smear (ETN has numerous eosinophils).  Most of you nailed this one.  Good job!

Tuesday, June 19, 2012

Allergic Contact Dermatitis Secondary to Smoke

This was a brutally tough question.  This patient was helping her mom and dad clear some brush from their property near San Antonio, and she came down with this mysterious swelling and itching on her face. At first, I thought it was urticarial or angioedematous, but the problem was that there was no lip swelling, the distribution was asymmetrical and somewhat patterned.  Using those clues, I moved away from hives and angioedema and started looking for a cause for the swelling.  Knowing now what you know, what is your best guess for the etiologic agent given these clues? One point.

Addendum:  Most of you got this right after the above clues were revealed.  The patient's parents had gathered up all the brush and weeds (and poison ivy) from the land they were clearing, started a bonfire and our patient walked through the smoke, with her left side facing the bonfire.  Therefore, the most affected side, her left, got the biggest dose of the toxicodendron dose from the smoke.

The take home message is this, as if I haven't said it before:  Trust your eyes.  If it doesn't add up with the story, ask leading questions, and don't let the patient drive the interview.  In this case, only after I figured out that it was an aerosolized allergen did the patient and parents admit as to what really happened.  Now that you know the story, the picture makes a lot more sense.  Trust your eyes.

Monday, June 18, 2012

Deficiency of Uroporphyrinogen Decarboxylase

Uroporphyrinogen decarboxylase, the enzyme deficiency of which leads to porphyria cutanea tarda, is the most common of the heme-synthesis enzyme deficiencies.  Of course, it is characterized by many cutaneous manifestations, including scarring and blistering and skin fragility of the hands, hypertrichosis of the bitemporal area, subungual onycholysis, and as you can see above, extensive photoaging and textural differences on the nasal bridge.  This finding is also common for those who have Erythropoietic Protoporphyria, and so if anyone had said Ferrochelatase as the answer, I would have given them credit.

As we have discussed previously with PCT, it is important that patients who display the findings of PCT get a full workup for liver disease and hemochromatosis, either familial or alcohol induced.The mechanism of alcohol induction is thus:  the enzyme is present in large concentration in the hepatocytes, and when large amounts of ethanol are ingested, it causes oxidative damage to the hepatocytes, which in turn damages the cytosolic enzymes within.  This patient, however, had estrogen-induced PCT, which is a story for another day.

Sunday, June 17, 2012

The Pulley Stitch

I love the pulley stitch.  The pulley stitch is a "get out of jail free card" for those of us who do a lot of surgery.  It allows the surgeon to put a lot more pull on the skin edges without tearing through the tissue, thus allowing you to close defects under significant tension.  The disadvantage is that it is very likely to leave a significant suture track, but there are times when that is secondary to the integrity of the wound.  One of our players called it a slip stitch, and then described it exactly as I did, above.

The way to tie a pulley stitch is to go near-far-far-near, resulting in that big external loop.  A vertical mattress suture is far-far-near-near, and if under great tension, often strangulates the wound margin.  Not good.  So, if you find yourself struggling to close a wound under tension, consider the pulley stitch.

Thursday, June 14, 2012

Ulnar Deviation Secondary to Rheumatoid Arthritis

As can be seen in this picture, severe rheumatoid arthritis is characterized by, among other things, significant ulnar deviation and flexion of the non-thumb digits.  The reason why this deviation occurs is that there is such articular swelling and inflammation, the phalangeal aspect of the joint is pushed off the metacarpal aspect, and so they slip off to the ulnar side of the hand.  There is also a rheumatoid nodule, as many of you pointed out.  The varied manifestations of RA are not worth repeating here, but since there are many inflammatory conditions that are associated with RA, it is important to recognize and take into account the preexisting disease when working someone up for another condition.

I'd also like to reflect on something we have briefly touched on before, but I was explaining to a friend that each one of my patient visits is, in many ways, like a mini-performance.  I assume the role (as we discussed before) the patient expects me to conform to (father, brother, friend, etc.) and hit my mark and say my lines.  It's a great way to hone my communication skills and ensure the patient gets the most out of the encounter.  And, it keeps my energy up at the end of a busy, tough day.  But hey, it's show business!!

Wednesday, June 13, 2012

Solar Elastosis

Well, I can't comment much on this one, except to say this woman should not have listened to the Fifth Dimension.

Tuesday, June 12, 2012

Immunofluorescent Image of Pemphigus Vulgaris

When you look at this image, you see a hint of the miracle that is our skin.  As you know, in pemphigus vulgaris IgG attacks the intracellular attachments that hold the skin cells together, resulting in loss of adhesion of these cells.  The blisters that form are only roofed by the stratum corneum (in which the cells adhere to one another by a different mechanism than the suprabasilar keratinocytes) , and so are fairly fragile, especially so in the mucosa, because the stratum corneum is relatively nonexistent there.  What does that translate to in clinical terms?  Thin walled, very fragile blisters that are easily burst, and erosions in the mouth, because of the lack of stratum corneum.

As a little aside, many people who have pemphigus are exacerbated by ingestion of members of the onion family;  as part of your management strategy, have them stay away from onions, garlic, leeks, shallots and the like.  

Monday, June 11, 2012

Tripe Palms

Malignant acanthosis nigricans can accompany, precede or follow the onset of internal malignancy.  Most cases are associated with an adenocarcinoma, most commonly of the stomach, but also the lung and breast.  Other types of internal malignancies have been noted as well.  It is more common in males but also can be found in females.  Tripe palms, as pictured above, is palmar acanthosis nigricans. Here's a trick:  if a nonobese male over the age of 40 develops acanthosis nigricans, particularly on the palms where there are thickened, velvety palms and pronounced dermoglyphs, then work him up!!!  Although it is not pathognomonic, up to 95% of tripe palm patients have an associated with internal malignancy.

Sunday, June 10, 2012

Actinic Granuloma

Actinic granuloma presents as papules and plaques on sun-exposed skin.  Lesions are usually numerous and may coalesce to form plaques that may cover much of the exposed skin.  It may be pruritic, persistent, and is more common in older patients.  Strangely, there is an association with temporal arteritis.  Although it may in some instances appear like granuloma annulare, the histopathology of the two entities is very different.  It can be differentiated from PMLE by the character of the lesions (firmer and often yellow red) and by the history, which would be a seasonal presentation, as we discussed previously.  The above picture is a detail from the same patient in the original picture.

Thursday, June 7, 2012

GSW Tattoo

One of the advantages of having done an inner city internship is that, when presented with this lady on Grand Rounds, I not only knew what it was, but guessed the right caliber (.38 special).  The blue is from the powder tattooing the skin, with the Tyndall Effect accounting for the bluish color.  I forget the exact details, but this lady was shot at close range with a .38 caliber handgun and somehow lived to tell the tale.  

While at Penn, I had several GSWs I had to deal with, one of which was a shotgun blast which soaked up 47 units of blood before the patient expired.  

The reason for giving you such an obscure presentation is not to frustrate you, but to give you a puzzle with very little information.  It's a good exercise, even if you don't get it right (nobody got this one) because all we are, in reality, is visual detectives.  Modern day Sherlock Holmeses, if you will.

Wednesday, June 6, 2012

Ichthyosis Vulgaris

Ichthyosis vulgaris is an incredibly common (roughly 1/250) condition which is a result of a defect in fillagrin synthesis, and it is autosomal dominant in its inheritance.  For a bonus point, tell me what autosomal dominant means in terms of how diseases are transmitted from parent to child.  It is characterized by large, flat scales on the lower legs, but also in the upper limbs, the back, chest, neck.  The scales predominate in areas that are not well supplied by sweat glands, such as intertriginous areas.  

It is differentiated from eczema craquele by the character of the scale and the location, being much more prominent and wider distributed than eczema craquele.  The picture of lamellar ichthyosis is different, in that the scales, if anything, are accentuated in the flexural areas and they are pretty much universal, as opposed to ichthyosis vulgaris.

If you had to choose an ichthyosis, you should pick ichthyosis vulgaris, because it is more common, hence its name.

Tuesday, June 5, 2012

Lentigo Maligna

Lentigo maligna is a tricky disease to diagnose in most cases, because the lesions are usually in a field of somewhat similar looking lentigines and SKs.  How to differentiate them from their benign brethren?  One is similarity.  Does the patient have a lot of lesions that are similar in character to the one you are examining?  It is very, highly, extremely, wildly unlikely that the patient will have numerous MISs, so if there are lots of other spots that look like this, then give 'em a pass.

Second is what I call the first glance phenomenon.  We often look at dark lesions peripherally before we put the full fovea centralis on the spot.  That "rod only" look often is a better discriminator for what is truly dark and what is less so.  In other words, if it catches your eye, you should REALLY have to talk yourself out of biopsying it, or go ahead and put a hole in it.  When in doubt...

Finally, get up close and personal with it.  Scrape your fingernail across it.  What's the texture?  Smooth like a snake or crusty like a tortoise?  

As an aside, I studied for a few months at the Armed Forces Institute of Pathology, one of the preeminent derm path labs in the world, and the older guys there used to call LM/MIS "precancerous melanosis" because they didn't believe those lesions were truly cancer.  I'm not completely of one mind on the subject, either.

Monday, June 4, 2012

Bullous Pemphigoid

Bullous pemphigoid is an autoimmune disease that attacks proteins in the basement membrane known variably as 230 and 180 kD (kiloDalton) proteins or Type XVII Collagen. These proteins are in the basement membrane and act as intrinsic parts of the hemidesmosome which tacks down the basal cell keratinocytes to the basement membrane.  Once these proteins are attacked and lysed by the autoantibodies, they float up because they are no longer attached, and lymphatic fluid fills up the space underneath the floating sheets of keratinocytes, resulting in fluid-filled blisters.  

If you look at the pic above, you see very tense blisters.  The tense blisters are tense because they contain the entire epidermis on top of them. More important, you see the red, inflamed background.  That red background is where the autoantibodies are attaching themselves to the hemidesmosomes and thus triggering the lytic reaction, and so THAT is the area where you want to do your biopsy for IF.  What you will see on H and E is lots of eosinophils, some neutrophils, and the very beginnings of separation of the basement membrane from the basal layer.  

As I have said before, it takes three hands to do an IF biopsy for this condition:  One to hold the skin, one to hold the punch, and one to direct the biopsying hand away from the blisters and onto the inflamed skin.

For those of you who guessed contact, the info that he was getting worse should have steered you away from that. He should have gradually improved over the two weeks.  For those of you who guessed bullous impetigo, I would have given you a better pic of the honey colored crusting.  Also, the blisters would have been more flaccid.

Sunday, June 3, 2012

African Cheetah

Why is this cat laughing?  Well, it comes down to this:  He's got a dead warthog behind him, he is the fastest creature in the world, and he just scared the bejeezus out of a bunch of American tourists.  So, it's a pretty good cheetah day.  The clues to a cheetah are its body size (usually smaller than a leopard), the spots as opposed to rosettes on the pelt, and finally as several of you pointed out, the vertical lines on the medial face.  Although the reality is they are very risk avoidant (their bones are too fragile to go head-to-head with other predators) and will usually run from a fight, this guy put on a pretty good bluff for us.  

So, on to the quest for (medical) knowledge!  Enjoy this month, I will be serving up some tasty diagnostic dilemmas. Sur la planche!