Pediatric emergency medicine trisk 587

trimethoprim intravenously every hours) should be considered if there are respiratory symptoms, with or without a positive chest radiograph Treatment for suspected PCP should not be delayed because of concern of interfering with the diagnostic workup Fungal infections, with the exception of oral thrush, are uncommon in HIV-infected children However, candidal sepsis should be considered in hospitalized patients who not improve with antibiotics Chronic fever is common in HIV-infected children and has a broad differential diagnosis The major focus of such an evaluation in the ED is to rule out acute bacterial infection A careful history and physical examination should be followed by a CBC, urinalysis, chest and sinus films, and blood, urine, and stool cultures Recurrent otitis media is commonly seen, and some children may have recurrent parotitis or sinusitis If no source is recognized on examination and the initial testing is negative, more unusual infections need to be considered Tuberculosis, although common among HIV-infected adults, is uncommon in children but may be more likely among adolescents Mycobacterium avium complex may cause chronic fevers in HIV-infected children This pathogen is often associated with anemia secondary to bone marrow infiltration and can be cultured from blood, stool, and bone marrow Numerous viruses can cause chronic infections associated with fever in these children EBV and CMV are among the more common, with CMV often presenting with chronic hepatitis and bloody diarrhea It may also cause pneumonia and retinitis A blood buffy coat specimen can be sent for quantitative CMV-antigen detection Most HIV-positive children with fever of unknown origin are hospitalized to facilitate the diagnostic process The possibility of drug fever must also be considered Two OIs warrant special attention: PCP and lymphoid interstitial pneumonitis (LIP) PCP is caused by a fungal pathogen and is the most common initial manifestation of HIV in the perinatally infected infant The infant or child typically is febrile, with marked tachypnea, wheezing, rhonchi, and diminished breath sounds Rales are not usually part of the PCP picture, and cough may be absent When coughing is present, it is typically dry and nonproductive Over hours to days, the patient develops hypoxia and increased respiratory distress Initial ED evaluation should include beginning supplemental oxygen, obtaining pulse oximetry, an arterial blood gas, a chest radiograph, and serum LDH levels Radiographs may show a diffuse interstitial (“ground-glass”) pattern, but infants may develop patchy infiltrates or complete opacification of the lung fields The diagnosis often requires bronchoscopy with specimens sent for silver stains However, if the ED physician suspects PCP, it is appropriate to start IV TMPSMZ at a dosage of mg/kg/dose of TMP every hours The child should be hospitalized for close observation and further evaluation as needed In general, patients with PCP not respond rapidly to antibiotic therapy Patients intolerant of TMP-SMZ can be treated with systemic (not aerosolized) pentamidine (4 mg/kg/day as a single daily dose) or atovaquone, but these should be considered second-line agents Corticosteroid therapy in children with severe PCP improves survival and is generally recommended for patients with PaO2 less than 70 mm Hg or an alveolar–arterial gradient of greater than 35 mm Hg Standard precautions are indicated LIP is a lymphoid hyperplastic condition associated with both HIV and EBV infections LIP results in a slowly progressive hypoxemic condition in children outside infancy The most common symptoms are chronic cough, mild tachypnea, generalized adenopathy, marked hypoxemia, and digital clubbing Chest radiography reveals an interstitial nodular pattern, and bronchiectasis can be seen on high-resolution CT of the chest The diagnosis is confirmed via biopsy Fever is an unusual manifestation of LIP and should prompt evaluation for secondary pyogenic bacterial infections Therapy may be with antiretroviral therapy; in acute respiratory compromise, empiric corticosteroid therapy may be warranted If the PaO2 is less than 65 mm Hg, LIP is treated with to mg/kg/day of prednisone (maximum: 60 mg/day) for to weeks and subsequently tapered to maintain the PaO2 above 70 mm Hg If the patient is febrile, tuberculosis or MAI must be ruled out before beginning steroid therapy Management: Whenever a child with HIV infection presents with high-grade fever (temperature higher than 39°C or 102.2°F), a complete blood cell count (CBC) with differential and blood culture is recommended If the child is still in diapers, a urine sample should be obtained for analysis and culture Older children who are toilet trained usually complain of dysuria or frequency if they have a UTI If the child has any respiratory signs or symptoms, including isolated tachypnea, or if the CBC has an elevated leukocyte count with a shift to left, regardless of the presence of respiratory signs, pulse oximetry and a chest radiograph should be ordered The WBC count is best evaluated in relation to baseline counts because many HIV-infected children have some degree of leukopenia If it is known that the child is not leukopenic or the baseline is not available, a WBC count of 15,000/mm3 or more should be considered suggestive of bacterial infection If the child appears well and the evaluation has not revealed a source for the fever that requires hospitalization, the child may be sent home (if the child’s caregiver can be easily contacted and has the means to return if necessary) with instructions to return if symptoms worsen or if the patient develops lethargy or will not take adequate amounts of fluids Clinicians can choose to offer empiric antibiotics (e.g., ceftriaxone) for children being considered for outpatient care A follow-up evaluation by telephone or a revisit to the child’s regular provider or the ED should be scheduled for the next day HIV-infected children with severe immunosuppression (CD4%