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 criteriaLaboratory criteria Malar RashBlood (Low hemoglobin, platelets, or WBC) Discoid RashRenal disease (proteinuria, hematuria) Serositis (pericarditis, pleuritis)Anti nuclear antibody + Oral ulcersImmunologic: 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