December 15th, 2012
We asked you about the treatment to this skin rash… and the answer is….
a. Coal Tar
This is the classic salmon pink rash of psoriasis. You can see the surface has a scaly appearance.
As the rash in psoriasis is palpable and spread over an area of >0.5cm it is called a plaque not a macule – (If it was an impalpable area of colour change it would be called a patch).
Skin psoriasis is treated by emmollients, vitamin D analogues, coal tars, dithranol, topical steroids and oral retinoids. Methotrexate and Anti TNF therapy in addition to other immune modulating therapies are used in severe cases. Remember the four main types:
- plaque (seen here)
- pustular (pustules often occuring on the hands and feet)
- guttate ( teardrop lesions -sometimes occuring following a streptococcal infection)
- erythrodermic (diffuse skin involvement – potentially lifethreatening)
Capsaicin is a Rubefacient: a topical skin irritant. Its use is based on the principle that irritation of the skin produces a “distracting” effect from the pain from OA/ neuropathy (e.g. post herpetic neuralgia).
It is used topically for osteoarthritis and neuropathic pain.
Capsaican is the “active” ingredient in chillies which gives them their heat. Its use over a rash like psoriasis would be liable to produce excruciating pain and significant inflammation.
October 15th, 2012
We asked you about this 27 year old female who presented with a 3-day headache. After looking at her lumbar puncture results, the diagnosis is….
a. Benign Intracranial Hypertension
The pressure is very high! The CT was normal essentially excluding raised intracranial pressure secondary to an obstructive hydrocephalus (e.g. meningioma obstructing the 4th ventricle draining CSF). The red cells are high in the first sample of CSF but as further CSF is tapped off, this clears. This supports a slightly “traumatic” tap. Xanthochromia testing in the sample is negative, providing no evidence of a prior bleed into the CSF which has then been broken down into xanthochromia.
To diagnose a S.A.H. you have to have either blood or altered blood in the CSF. As a rule of thumb you should have “no” red cells in the CSF if its not a traumatic tap and there is no other pathological processes.
The diagnosis is BIH. This is reasonably common in young people and is not benign: untreated it can threaten sight. Treatment is via means to reduce CSF pressure e.g. repeated lumbar punctures.
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September 29th, 2012
A 27 year old female presents with a headache. She has had it for 3 days. She has no other symptoms. She has a normal CT brain.
Her lumbar puncture shows the following.
| CSF Opening Pressure (10-20cm H20) |
42 |
| Macroscopic appearance |
Clear |
| Bottle 1Bottle 3 |
RBC 150 mm3, WCC 0mm3RBC 0mm3,WCC 0mm3 |
| Gram stain |
Negative |
| MCS |
No growth |
| Glucose |
4.5 |
| Xanthochromia |
negative |
What is the most likely diagnosis?
a. Benign Intracranial Hypertension
b. Tension headache with traumatic Lumbar Puncture
c. Sub arachnoid haemarrage missed on CT
d. Stroke
e. Sub Arachnoid Haemorrage
f. TB Meningitis
Leave your answer below!
August 1st, 2012
A medical student sustains a needlestick injury from an intravenous drug user. Unfortunately this user is Hepatitis C positive.
Regarding Hepatitis C which of the following statements is true?
- a. Vaccination to hepatitis C is routinely available to healthcare professionals and confers some protection
- b. The chance of transmission of hepatitis C is around 3%
- c. The chance of transmission is around 0.3%
- d. Hepatitis C if transmitted will lead to liver failure in that individual
- e. The chance of transmission is around 30%
Leave your answer as a comment below; answer in a few days!
July 25th, 2012
We asked you this tough Oncology question. Thanks for all your guesses!
For those of you who answered with this reponse, you are right…
a. Beta HCG
c. AFP (alfa fetoprotein)
f. PSA (prostate specific antigen)
The other tests are not specifically designed as “screening tests” for patients. For example a man losing weight should not simply have a CEA, CA19-9 and Ca 125(!) checked as:
- there is no replacement for clinical examination and planned investigations
- “negative results” do not negate the need for further investigation
- “positive results” do not necessarily infer any diagnostic specificity.
A careful history, examination, investigations and clinical assessment is much more important than just requesting lots of tests.
PSA, HCG and AFP are different as a result of their sensitivity and specificity and relative prevalences of each of the conditions they act as “markers” for namely: prostate cancer, Choriocarcinoma and hepatoma.
The other tests are not validated as ‘cancer screening’ tools and should not be used in this way.
Commonly cited tumour markers:
| Substance |
Associated with |
Notes |
| AFP |
Hepatoma: also some seminomatous testicular tumours |
Remember high risk populations including hepatitis virus and alcoholics |
| CEA |
Colorectal cancer |
Note its use in follow up rather than diagnosis |
| Calcitonin |
Thyroid Medullary cancer |
Diagnosis and follow up |
| CA125 |
Ovarian cancer |
|
| Urinary Catecholamines |
Phaeochromocytoma |
Remember to consider this in patients presenting with palpitations and resistant hypertension |
| Protein Electrophoresis |
Myeloma |
Any questions that include the test “immunoglobulins and protein electrophoresis” is essentially looking for the monoclonal production of immmunoglobulin seen in myeloma |
| Ca 19-9 |
Pancreatic Cancer |
Levels of >10,000 can correlate with metastatic spread in this aggressive tumour |
| Beta HCG |
Choriocarcinoma |
Almost ‘always’ elevated. Also elevated in germ cell tumours |
| PSA |
Prostate cancer |
|
| Urinary 5HIAA |
Carcinoid |
Symptoms often imply metastases |
