FUO Flashcards
1 yr old immunization unknown adoptee from china presents with a whole body brick rash (darker on the trunk) cough (crusty runny nose) and some diarrhea. Child is fussy. Differential diagnosis?
Measles- a very infectious agent due to viral spread through respiratory droplets. Systemic viral illness.
Define fever of unknown origin
Three outpatient visits or three days in the hospital or 1 week of “intelligent and invasive” ambulatory investigation
4 Categories of illnesses to consider in a recent traveler with a fever
- parasitic organism (malaria)
- enteric pathogens
- respiratory pathogens
- systemic viral illnesses (especially for pediatrics)
What are some causes of a “fever”?
- infections
- mechanical trauma (crush injury)
- neoplasm
- medications
- autoimmune diseases
- drugs
- CNS disorders
- acute hemolysis
- large vascular accident
- malignant hyperthermia
- acute metabolic disorders (pheochromocytoma, delirium tremens)
Key things about fevers
do fevers = infection? What does a fever usually mean?
NOT infection - think inflammation
- TNF, IL1, IF
When you think Fever, what are the three main categories you always consider?
Infection
Cancer
Immune disease
What is fever rarely due to?
Disorders of auto regulation
- CNS injuries,
What is Dr. Petersdorf 1961’s definition of fever of unknown origin?
- fever higher than 101 on several occasions
- persisting without diagnosis for at least 3 weeks
- at least one week of investigation at a hospital
How does the duration of fevers differ between infections, malignancies, and immune diseases?
- Infections: typically RAPID onset/resolution., except in chronic inflammation (TB, Lyme disease, HIV, hepatitis viruses, parasites - will cause inflammation when they move/die.)
- malignancies: usually declare themselves in WEEKS
Immune diseases: wax and wane for MONTHS/YEARS (typically less urgent), vague findings
What are the key questions to ask about FUO
- DURATION- series of recurrent episodes? One long episode?
- TEMPORAL PATTERN? Normal intervals In between? Occurring in hours/days?
-
* is the patient ill appearing?*
- acutely ill? Toxic (visibly in distress) unstable vital signs
- weight loss?
- other finding os on ROS and exam
What is the stepwise evaluation (history taking) for a patient with FUO
Life history of health Family risk of chronic disease (cancer, immune) Travel- location, food/water/insect exposure Pets/animals Family household school exposures History of THIS complaint: - onset, duration, pattern - patient vs observers - signs and symptoms
Physical exam for FUO:
** look for real manifestations of systemic disease- not secondhand report**
- signs of inflammation (fever, wt loss)
- focal pain/tenderness (dolor, rumor, tumor, calor)
- look at common problem sites: mucous membranes, sinuses, lungs, careful abdominal exam
- msk- joint inflammations
- integument- health of skin: rashes?
- liver spleen lymph nodes
FUO first tier of labs:
- WBC (shift to PmNs), C-reactive protein, ESR
- urinalysis, BUN, bili,
- LDH (cancer)
- PPD, HIV
Second tier of labs for FUO
More exotic Virals: ebv, Cmv, hep b and c Bacteria: Lyme, syphillus, rickettsia, etc Parasites: toxo, Autoantibodies: Ana, dsdna, sm, GI panel
Malaria smears, stool cultures,
Eye exam
Cardiac exam
repeat skin, joint, Ln, spleen liver exam
Imaging to do for FUO in second tier
Ct
MRI
U/S
Third tier for FUO analysis
Go fishing Lots of blood draw Ln bm biopsy PET scan One central manager by now coordinating all this
Watch and wait is ok for stable pts
18 yr oldwith lymphadenopathy and fever- fatigue, ns, myalagias, flat affect, chains of Ln inflamed, African American female
Anemic, tissue inflammation (alt ast in the 100’s), high crp, high sed rate
Consider autoimmune: SLE (lupus)
Ana +
Anti ds DNA+
Anti sm +
4 yr old with parotitis- one week of fullness of neck tender, and warm. Had mumps dx 6 weeks ago, and “mumps” flared again 1 week later (rare for mumps) => recurrent parotitis?
Prolonged loss of appetite for weeks/months Anemic Arthritis in ankles Low platelet count High LDH
Atypical lymphoblasts- 62,000 WBC
- acute lymphocytic leukemia
7 year old with fever. Initial fever 3 weeks ago nausea and diarrhea. Traveled all over Central America. Dramatic fevers chills3-4x/day for 10 days. Pale, quiet, noting specifically wrong with him clinically or physically.
Typhoid fever? Strong abx response to salmonella (common is post illness)
=> enteric fever
