DERMATOLOGY...."Which is which"???

There are good several diseases in dermatology that sound CONFUSINGLY ALIKE.
These will very likely be covered on your examination...so, let's cover them and simplify.


Q:   What is ECHTYMA GANGRENOSUM?


A:   It is an infection of the skin...caused by an undelying  PSEUDOMONAS AUREGINOSA
       systemic infection. Common in the ICU setting.




Q:   What is PYODERMA GANGRENOSUM?


A:   It is an INFLAMMATORY condition...causing necrotizing-bullous eruptions, especially of
       the extremities.  Corticosteroids WILL IMPROVE  and antibitotic (e.g. dapsone) may have added effect.
       There are 3 types...and 70% will be assiciated with a variety of underlying diseases, e.g.
       MULTIPLE MYLOMA, IBD (Crohn's disease/Ulcerative colitis), ARTHRITIS(primarily RA) and DM.



Q:  What is a PYOGENIC GRANULOMA?


A:  It is a HARMLESS skin growth, also called Eruptive Hemangioma, that can occur on any part
      of the body, especially fingers and gingiva.  The name remained...because it was initially thought
     of as being infectious in etiology.



Q:  What is SEBORRHEIC KERATOSIS?


A:  It is a WARTY growth of the skin....predominantly of the elderly....causing a "STUCK-ON"
      appearance, commonly seen on the scalp, face, chest and back.  Can transform into SQUAMUS
      CELL CARCINOMA...in immunocompromised patients.



Q:  What is SEBORRHEIC DERMATITIS?


A:  It is a SCALY eruptive lesion seen commonly in AIDS patient and in  patients suffering
      from PARKINSONISM.  The rash typically affects the face, nose, scalp.
      Causative organism is PITYROSPORUM OVALE.
   



Q:  What is ACTINIC KERATOSIS?


A:  It is a PRECANCEROUS condition.....can lead to SQUAMUS CELL CARCINOMA.
      They are "red itchy bumps"...occuring especially on SUN EXPOSED surfaces, such as
      hands, forearms. At times the lesions can BLEED and become painful.



Q:  What is DERMATITIS HERPETIFORMIS?


A:  They are MICROABSCESSES and IgA DEPOSITS on the basement membrane of the skin,
      causing BLISTER like lesions of the elbows, low back, buttocks...likely due to immune mediated
      etiology.   It is commonly assiciated with CELIAC SPRUE...thus, a GLUTEN FREE diet, will
      frequently clear the dermatosis.



Suggest a good memorization of these VERY SIMILAR SOUNDING disorders, as they will be
asked on the examinations. 


  

URINALYSIS.....diagnostic clues.

URINALYSIS can give us instant CLUES to  an underlying pathology...and is also a
frequent topic of the boards.  We'll review some common and (not so common) findings.



1.   CALCIUM OXALATE...usually associated with Ulcerative Colitis or Ethylene Glycol Poisoning.

2.   ERYTHROCYTE CASTS...Pathognomonic for Acute Glomerulonephritis (AGN)

3.   HYALINE CASTS....implies moderate to severe dehydration...eg. Prerenal Azotemia

4.   GRANULAR CASTS...imlplies necrotic insult, such as Acute Tubular Necrosis (ATN)

5.   MUDDY BROWN CASTS....usually due to Acute Tubular Necrosis. (ATN)

6.   EOSINOPHILURIA.....very suggestive of ALLERGIC Interstitial Nephritis.
                                             (Best diagnosed with use of Hansel's stain).

7.   WHITE CELL CASTS...also commonly found in ALLERGIC Interstitial Nephritis.

8.   STERILE PYURIA...is a classic finding in Acute Interstitial Nephritis. (AIN).

9.   TUBULORETIC INCLUSIONS....pathognomonic for renal manifestation of HIV.

10.  URINE OSMOLALITY....reflects the kidneys ability to process water 
                                               An INCREASED osmolality = Concentrated urine (dehydration).
                                               An DECREASED osmolality = DILUTE urine.



Thanks for your time...be back shortly.

QUICK TAKES II

Q:   What is Lateral Epicondylitis?


A: 

QUICK TAKES

We'll review some uncommon clinical scenarios...not so uncommonly covered, by the medical boards.


Q: What does a WIDENED MEDIASTINUM most commonly imply?



A: 1. Dissecting Thoracic Aneurysm
2. Inhalational Anthrax

3. Improper patient positioning during CXR (this is most common).




Q: What does finding of CALCIUM OXALATE in urinalysis imply?


A: 1. Ethylene Glycol Poisoning
2. IBD (Crohn's Disease)




Q: What are BURTON'S LINES?



A: Bluish discoloartion along the gingival margins of teeth...in CHRONIC LEAD POISONING.
Not seen in edentulous persons. It is a highly suggestive sign!






Q: What is a PINGUECULA?



A: It is a harmless, yellow-while collagen (jelly-like) depostion on the corneal surface.
Can be removed for bothersome-cosmetic reasons.




Q: What are MEES' LINES?



A: A whitish transverse discoloration of the fingernails...seen in ARSENIC or LEAD poisoning.






We'll continue soon!

HEMATOLOGICAL EMERGENCIES...

We'll continue with interesting topics in hematology, specifically disorders that need quick diagnosis and management.



1. WHAT IS TTP (Thrombotic Thrombocytopenic Purpura)?


A: TTP is an uncommon but not infrequent blood dyscrasia, that primarily affects
platelets. As the name implies, platelet numbers are very diminished causing
cutaneous purpura. This is primarily a disease of ADULTS.

The PENTAD for diagnosing TTP are:
1. Thrombocytepenia
2. Purpura
3. Confusion (mental status changes)
4. Renal Insufficiency/failure
5. Fever

Usually not all 5 charactersitic findings are present. To make the diagnosis, besides the low
plateletet count and reactive purpura...the presence of an additional finding, will do.





2. WHAT IS THE TREATMENT FOR TTP?


A: Emergent PLASMA EXCHANGE, as well as meticulous supportive care.





3. WHAT IS ITP (Idiopathic Thrombocytopenic Purpura)?


A: ITP predominately affects CHILDREN in about 90% of cases, due to immune phenomenon.
Generally occurs as after a recent VIRAL EXANTHEM, UPPER RESPIRATORY
INFECTION, INFECTIOUS MONONUCLEOSIS,etc. Clinically, similar to TTP above.



4. WHAT IS THE TREATMENT OF ITP?


A: Medical treatment for ACUTE TTP, with active bleeding consist of GLUCOCORTICOIDS.
If steroids are unhelpful...IVIG (Intravenous Immunoglobulin) infusion is recommended.
Emergency SPLENECTOMY is reserved for severe ITP.




5. WHAT IS POST (PLATELET) TRANSFUSION PURPURA?


A: Occurence of LOW PLATELET COUNT 7-10 DAYS, after platelet transfusion.
Patients usually present with bleeding from gums, purpura and severe thrombocytopenia.
It is due to presence of an ANTIGEN called...HPA-/a.

6. WHAT IS THE TREATMENT?


A: IVIG or PLASMAPHERESIS.



Thanks for your time!