Download Fever of unknown source: Cases

Fever of unknown source: Cases
Family Medicine Specialist CME
October 15-17, 2012
Pakse
Objectives
• Describe an initial approach to physical exam to
a patient with fever of unknown source, to help
guide further investigations
• Order appropriate tests to diagnose malaria
• Recognize that lupus is diagnosed both by
clinical and laboratory criteria.
• Describe an approach to investigating suspected
cancer
Case 1: Approach to infectious causes
• A 60 year old male is taken to the hospital because
of confusion for 3 days. He cannot provide any
other history. In the hospital, you notice that he has
a fever of 40 degrees Celsius, heart rate of 110bpm,
and blood pressure of 100/60.
• What do you want to do next?
• What will you look for when examining someone
with a fever and you do not know where the source
could be?
Physical exam in someone with fever
▫ Neurologic:
 Confusion or altered mental status
 Unequal pupils, focal motor deficits (brain abscess)
 Neck rigidity (meningitis)
▫ Head and Neck:
 Infection of ears, mouth, throat, dental abscesses
▫ Heart:
 New murmur (endocarditis)
▫ Lungs:
 Crackles, dullness to percussion, decreased air entry
(pneumonia, infected pleural effusions)
Physical exam in someone with fever
▫ Abdomen:
 Pain (can be from inflammation or perforation of nearly
any of the intraabdominal organs. For example:
appendicitis, cholecystitis, perforated peptic ulcer)
 Masses (abdominal abscesses)
▫ Pelvis:
 Suprapubic or flank pain (urinary tract infection,
pyelonephritis)
▫ Skin:
 Redness, heat, and pain (cellulitis), Ulcers, Necrosis
(scrub typhus), Petechiae (dengue fever, endocarditis),
What investigations would you do if you find…
• Neurologic abnormalities?
CT head and/ or lumbar puncture
• New heart murmur?
Blood cultures if available
Echocardiogram to look for endocarditis
• On lung exam: Crackles, bronchial breath sounds,
decreased air entry, dullness to percussion
Chest X-Ray to look for pneumonia and its
complications
What investigations would you do if you find…
• Severe pain on palpation of abdomen
Abdominal X ray to look for bowel wall thickening
(such as with colitis), obstruction, or free air
Ultrasound or CT of abdomen
• Flank pain or suprapubic pain
Urinalysis to look for ++ white blood cells
Urine culture if available
Ultrasound or CT of the kidneys to look for
abscess
Case 2
• A 40 year old female presents with 4 days of
episodic fevers, chills, headaches, and muscle
pains occurring every 48 hours.
• Based on this limited history, what infection
might she have?
• What investigation(s) will you do?
• What test will help you confirm your diagnosis?
Malaria Investigations
• If available, do blood cultures to rule out other
infections
• Lab tests in malaria that can be abnormal:
▫ Complete blood count: Often shows anemia
 Most do not have an elevated white blood cell count
▫ High bilirubin and LD consistent with hemolysis
▫ Elevated liver enzymes (AST and ALT)
Diagnosis of Malaria
• Thick and thin blood smears
▫ Thick smears are more sensitive to pick up
malaria
▫ Thin smears are to help determine the species of
Plasmodium causing the infection
• Why is knowing the species of Plasmodium
causing the malaria infection important?
Diagnosis of Malaria
• The 2 most common species in Lao PDR that
cause Malaria are P. falciparum and P. vivax
• Important to know which species because it
affects treatment
▫ P. falciparum is resistant to chloroquine but P.
vivax is not
▫ P. vivax can hide in the liver and cause relapse of
disease even after chloroquine treatment. Prevent
relapse by adding primiquine (14 days) to
standard malaria treatment
Case 3
• A 24 year old female presents with fever, rash on
her face and scalp, photosensitivity, and joint
pain to her hands.
• What disease does she have that could be
causing her fever?
• How do you diagnose this disease (what are
some clinical + laboratory features) ?
Lupus
• Diagnostic criteria (4/11)
Clinical criteria
Laboratory criteria
Malar Rash
Blood (Low hemoglobin, platelets, or WBC)
Discoid Rash
Renal disease (proteinuria, hematuria)
Serositis (pericarditis, pleuritis)
Anti nuclear antibody +
Oral ulcers
Immunologic: Anti double stranded DNA +
Arthritis of 2+ joints
Photosensitivity
Neurologic (seizures, psychosis)
Lupus
• What investigations should be ordered?
▫ Complete blood count
 Anemia, Thrombocytopenia, Leukopenia
▫ Creatinine
▫ Urinalysis
 Proteinuria, hematuria
▫ Antinuclear antibody (ANA)
▫ Anti double stranded antibody (Anti dsDNA)
▫ Electrocardiogram
 If patient has pleuritic chest pain, and suspect
pericarditis
Case 4
• A 65 year old man presents with 1 month history
of fevers. He also has noticed blood in his urine
and constant abdominal pain. He has no
appetite and has lost 40 lbs of weight in the last
3 months. On exam, you can palpate a large
mass to his right flank.
• What is the diagnosis?
• What investigations would you like to do?
Cancer
• Diagnosis is likely renal cell carcinoma
• If you suspect cancer, the first step is to image
the suspected area.
▫ In this case:
 Abdominal ultrasound
 CT abdomen
▫ If the images are very suspicious for malignancy,
then look for regional or distant involvement with
more imaging (eg. CT chest)
Cancer
• Generally, if the images are consistent with renal
cell carcinoma and there is no evidence of
distant metastases, the next step is removal of
the involved kidney and sending that tissue for
pathology if available