Fever on the CCFP exam

Approach

• Fever is a rectal temperature of 38.0 °C or more, at home or in the clinic. Treat a temperature under 36.0 °C the same way.
• Looking well does not rule out infection. Bacteria in the blood turn up in 3.0% of febrile babies up to 28 days, and 1.6% at 29 to 60 days.
• Up to 60 days, test every febrile baby: complete blood count with absolute neutrophil count (ANC), procalcitonin, blood culture, and urine for analysis and culture.
• At 29 to 60 days, use the PECARN rule (from the Pediatric Emergency Care Applied Research Network; table). All three normal means low risk: no routine lumbar puncture (LP).
• A high ANC or procalcitonin: do an LP, start intravenous (IV) antibiotics, and watch until cultures are negative at 36 hours. A positive urinalysis alone, with normal markers, does not call for an LP.
• Chest x-ray only for real breathing trouble: more work of breathing, or an oxygen level of 96% or less after the nose is suctioned.
• An ill-looking baby: airway, breathing and circulation first. Take cultures and give antibiotics without delay. The LP can wait until the baby is stable.

Approach

• No antibiotics for colds, flu-like illness, or sinus symptoms that have lasted under 7 days.
• No antibiotics for bronchitis or asthma in adults, or for bronchiolitis in children.
• Sore throat: antibiotics only with a positive clinical score (Centor or FeverPAIN) and a positive strep test.
• Ear infection: treat the pain first. Watchful waiting suits mild cases.
• In a young infant, a positive virus test does not rule out bacteria in the blood or spinal fluid. Still do the age-based work-up.
• A low-risk infant aged 29 to 60 days needs no empiric antibiotic.
• Babies with a high ANC or procalcitonin get IV antibiotics. A positive urinalysis with normal blood markers is treated too, by mouth or IV.

Approach

• Choose by age and likely germ (table). Change the drug once culture results and sensitivities are back.
• Infant 29 to 90 days who needs treatment: IV ceftriaxone 100 mg/kg every 24 hours. Add vancomycin 15 mg/kg every 6 hours only if meningitis is suspected.
• Infant 29 to 90 days with normal blood markers and a presumed urinary infection: oral cefixime 8 mg/kg once a day is an option.
• An infant at risk of herpes simplex virus (HSV), such as blisters on the skin or age under 14 days, needs an LP for HSV testing and IV acyclovir 20 mg/kg every 8 hours.
• Child over 2 months with suspected bacterial meningitis: ceftriaxone or cefotaxime, plus vancomycin. Add ampicillin if the child's immune system is weak.
• Child with pneumonia treated at home: amoxicillin, not a broader drug.
• A mild penicillin reaction in the past is no reason to pass over a first-choice penicillin or cephalosporin.

Approach

• Go back to the history and exam, and repeat them: travel, animals, new drugs, a new heart murmur, weight loss, joint pain.
• Take blood cultures before any antibiotic, as long as that does not delay treatment of a sick patient.
• A child with fever for 5 days or more: look for Kawasaki disease. Check the eyes, lips and mouth, hands and feet, skin and neck nodes.
• An infant with fever for 7 days or more and no cause: think of incomplete Kawasaki, even with few signs. Check the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP).
• Kawasaki needs an echocardiogram (heart ultrasound) of the coronary arteries. A normal first one does not rule it out; repeat it at 2 and at 4 to 6 weeks.
• Do not wait for the echo to treat. One dose of IV immunoglobulin (IVIG), 2 g/kg in the first 10 days of fever, cuts the aneurysm risk below 5%.

Approach

• Meningitis in infants: fever, poor feeding, drowsiness, vomiting and irritability, sometimes a rash. A stiff neck is uncommon.
• Meningitis in older children: headache, neck pain or stiffness, and a lower level of consciousness.
• Sepsis: an infection with a fast heart rate, fast breathing and fever. Check capillary refill, blood pressure and mental state.
• Higher risk of sepsis: cancer, no spleen, or a weak immune system from illness or drugs.
• Under 60 days, the absence of fever does not rule out sepsis.
• Fever with a new heart murmur, a heart valve problem or injection drug use: think of endocarditis. Take blood cultures before any antibiotic.

Approach

• Suspected meningitis: give antibiotics without delay. If the LP cannot be done now, treat anyway and transfer.
• Put off the LP for shock, a bleeding problem, skin infection at the site, or signs of brain swelling. Draw blood cultures first.
• Dexamethasone, if given, goes just before, with, or within 4 hours of the first antibiotic dose.
• Sepsis: antibiotics ideally within 1 hour. Do not wait for results.
• Shock: give 10 to 20 mL/kg of balanced crystalloid over 5 to 20 minutes. Reassess after each bolus for crackles or a large liver.
• Heat stroke or neuroleptic malignant syndrome: start cooling and support at once. Do not wait for the cause to be proven.

Approach

• Ask about heat, hard exercise, and every drug: new, stopped, or dose changed.
• Heat stroke: a very high temperature with confusion, seizures or collapse after heat or exertion. The skin may be dry or sweaty.
• Neuroleptic malignant syndrome: on an antipsychotic, with fever, rigid muscles, confusion and an unstable pulse or blood pressure. Stop the drug.
• Serotonin syndrome: on drugs that raise serotonin, with agitation, tremor, jerking reflexes (clonus) and fever.
• Other causes: drug fever, a blood clot, cancer, an overactive thyroid, and inflammatory disease such as lupus.

Approach

• Serious infection in an older adult may cause no fever.
• Look for other signs: new confusion, falls, eating less, fast breathing, a fast pulse or low blood pressure.
• Examine fully: chest, belly, skin, joints, and any lines or catheters.
• Do not test the urine for a change in thinking alone. Test it only with clear signs of infection.
• When an older adult does have a fever, it still needs a full search for its source.