Chapter 43 Fever and Rash (Case 13)
Case
A 2-year-old boy presents with a 3-day history of fever and a rash “all over.”
Speaking Intelligently
Distinguishing a benign cause of fever and rash from a potentially life-threatening one is of utmost importance but may be difficult. Serious bacterial illness tends to progress quickly, becoming fulminant in hours. An ill-appearing febrile child with a progressive petechial or purpuric rash or diffuse erythema (erythroderma) suggests a serious infection. Prompt assessment and stabilization of the ABCs (airway, breathing, and circulation) are the first step. Meningococcemia, RMSF, and TSS can cause inadequate perfusion and hypotension, requiring fluid resuscitation. Laboratory studies are drawn, and intravenous targeted antibiotic therapy is quickly initiated. If the likely cause is relatively benign, the workup may proceed with less urgency. In an immunocompromised child, however, even “mild” infections can be serious, and these children typically receive empirical broad-spectrum antibiotics. Realize that most cases of fever and rash in children are due to benign viral processes; however, in addition to serious bacterial infection, one must occasionally consider rheumatologic, immune-mediated, and oncologic etiologies.
Patient Care
History
Physical Examination
Tests for Consideration
Clinical Entities: Medical Knowledge
Meningococcemia | |
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Pϕ | Neisseria meningitidis is a gram-negative bacterium that colonizes the nasopharynx of approximately 5% of the population, and transmission is via respiratory droplets. Bacteremia and meningitis are forms of invasive disease with a mortality rate up to 10%. Meningococcal endotoxins cause extensive capillary injury, which results in the characteristic hemorrhagic rash and can progress to uncompensated shock and death. Extremity necrosis is a common and devastating sequela of fulminant meningococcemia. |
TP | Peak incidence occurs under 1 year and in middle to late adolescence. A brief nonspecific febrile prodrome precedes high fevers, mental status change, petechial or purpuric rash, and hypotension. |
Dx | Diagnosis is supported by gram-negative cocci on Gram stain of the blood or spinal fluid, and cultures are confirmatory. |
Tx | Supportive treatment consists of ventilation, oxygenation, and hemodynamic support. Ceftriaxone and vancomycin are preferred empirical therapy. If cultures confirm meningococcemia, coverage can be narrowed to penicillin G for 7 to 14 days.1 See Nelson Essentials 100. |
Rocky Mountain Spotted Fever | |
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Pϕ | RMSF is a tick-borne illness caused by Rickettsia rickettsii, a gram-negative coccobacillus that infects the small vessels of all tissues and organs, producing an infectious vasculitis. Host immune response contributes to diffuse vascular damage. |
TP | This entity is commonly confused with meningococcemia; clinical presentation is quite similar. Clues to distinguish RMSF from meningococcemia are high fevers preceding rash for several days, distal extremity petechial rash spreading centrally to include palms and soles, and travel to an endemic area. High prevalence areas in the United States include the mid-Atlantic, Southern, and south-central states. RMSF has a seasonal predilection for April through September. |
Dx | Diagnosis is often made clinically with supportive laboratory data, such as hyponatremia, hypoalbuminemia, elevated transaminases, anemia, and thrombocytopenia. Antibody titers to Rickettsia species are insensitive; comparative acute and convalescent antibody titers may be more helpful. |
Tx | Doxycycline is the treatment of choice for this life-threatening illness and should be started once RMSF is suspected, with supportive treatment as needed.1 See Nelson Essentials 122. |
Toxic Shock Syndrome | |
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Pϕ | Gram positive bacteria, typically Staphylococcus and Streptococcus species, produce toxins that cause a characteristic “erythroderma” rash, fever, tachycardia, and possibly hypotension as a result of toxin-mediated vasodilation. |
TP | Patients present with a diffuse red macular tender rash (which later undergoes desquamation), fever, and possible alteration of mental status or other signs of inadequate perfusion, such as oliguria. Females may have a history of tampon use. |
Dx | Diagnosis is clinical; namely, fever, the specific appearance of the rash, and signs of compensated shock (tachycardia), or decompensated shock (hypotension). Creatinine and liver transaminases may be elevated. Bacterial cultures are rarely positive, because toxins are responsible for clinical manifestations. |
TX | Intravenous antibiotics are promptly begun with a two-drug regimen: A bactericidal agent interfering with cell wall synthesis, such as a beta-lactam, and another targeting ribosomal toxin production, such as clindamycin. Intravenous fluids and cardiorespiratory monitoring are provided as needed.1 See Nelson Essentials 97. |