OCCULT BACTEREMIA
DEFINITION
Fever without obvious focus of infection (except otitis media) in a well-appearing child, and positive blood culture for a bacterial pathogen.
ETIOLOGY
Neonates
Group B streptococci
Escherichia coli
Listeria monocytogenes
Staphylococcus aureus
Coagulase-negative Staphylococcus (preterm infants, catheter-related)
Candida albicans (preterm infants, catheter-related)
Group B strep is the most common cause of neonatal septicemia
Children
Streptococcus pneumoniae (most common)
Neisseria meningitidis
Salmonella typhimurium
S aureus
Group A streptococci
SIGNS AND SYMPTOMS
Fever
Leukocytosis
PREDISPOSING FACTORS
Loss of external defenses (burns, ulceration, catheter).
Inadequate immune function.
Impaired reticuloendothelial function.
Overwhelming inoculum.
TABLE 10-1. Age-Based Management of Possible Occult Bacteremia in a Low-Risk Infant—Full Term, Previously Healthy, with Negative Laboratory Screen (Normal WBC Count and Urinalysis)
DIAGNOSTIC WORKUP
Blood and urine cultures.
Complete blood count (CBC): Normal WBC count is > 5000 and < 15,000 cells/cmL.
Lumbar puncture if < 60 days old.
TREATMENT
Treat to prevent progression to septicemia.
See Table 10-1 for age-based criteria.
SEPSIS
A 3-month-old female is brought to the ED with fever, vomiting × 1, → activity, and poor breast-feeding of 1 day’s duration. Previous history is unremarkable. Physical examination shows the following: “ill appearing,” temperature of 101.1°F (38.4°C), HR 196 beats/min, and no identifiable focus of infection. Think: Sepsis.
Young infants are at ↑ risk for infection. Initial presentation may be nonspecific signs and symptoms, and young infants lack focal signs of infection.
DEFINITION
A systemic inflammatory response to infection that includes hemodynamic and metabolic derangements.
Hypoperfusion abnormalities include lactic acidosis, oliguria, an alteration of mental status, and an ↑ alveolar-arterial oxygen gradient.
DIAGNOSTIC CRITERIA
Manifested by ≥ 2 conditions:
Hyper- or hypothermia (≥ 101.2°F [38.4°C] or < 96.8°F [36°C]).
Tachycardia (heart rate: infant > 160 bpm, child > 150 bpm).
Tachypnea (respiratory rate: infant > 60, child > 50).
WBC count > 15,000 or < 5000 cells/L and bandemia.
ETIOLOGY
Same as for occult bacteremia above.
SIGNS AND SYMPTOMS
Remember, a sick-looking, listless, infant who is not eating in the first 3 months of life with a rectal temperature < 98°F (36.7°C) is hypothermic and thus septic.
Vomiting is usual symptom in any infant with fever.
DIAGNOSIS
Same as for occult bacteremia.
Ten percent will have negative cultures.
RISK FACTORS
Younger at greater risk.
Prematurity.
Immunodeficiency.
Catheters.
Contact with known N meningitidis or Haemophilus influenzae infection.
Septic Shock
DEFINITION
Shock associated with systemic inflammatory response syndrome (SIRS) is defined as “hypotension persisting despite adequate fluid resuscitation, along with the presence of hypoperfusion abnormalities or organ dysfunction.” Septic shock is defined as shock plus clinical evidence of infection.
DIAGNOSTIC CRITERIA
Clinical evidence of infection plus meets the criteria for SIRS, plus one of the following:
Hypoperfusion requiring > 40 mL/kg isotonic fluid (crystalloid or colloid) and/or inotropic support.
Hypotension.
More than one manifestation of organ hypoperfusion.
TREATMENT
IV broad-spectrum antibiotics.
Manage shock with supportive therapy to maintain blood pressure, perfusion, and oxygenation.
Meningococcemia (Figure 10-1)
A 5-year-old boy presents with sudden onset of chills, fever, and listlessness. Physical examination shows a temperature of 103.5°F (39.7°C) and reddish-purple, palpable, nonblanching spots, mostly on the lower extremities and buttocks. He is rapidly progressing to shock. Think: Meningococcemia.
Typical presentation is sudden onset of fever, vomiting, headache, and lethargy. Most patients have petechiae on presentation. The infection can progress rapidly to profound shock and DIC.
Meningococcemia
Fever
Purpura
Rapid progression
Presents nonspecifically but progresses rapidly (within hours).
Most progress to septic shock due to endotoxin.
First petechiae, then purpura, and finally eschar (one of the rashes seen on palms and soles).
Typical rash distribution: Buttocks and lower extremities.
Adrenal hemorrhage (Waterhouse-Friedrichsen syndrome) and insufficiency common.
Establish diagnosis by culture of blood, cerebrospinal fluid (CSF), and skin lesions.
FIGURE 10-1. Meningococcemia.
(Reproduced, with permission, from Knoop KJ, Stack LB, Storrow AB, et al. Atlas of Emergency Medicine, 3rd ed. New York: McGraw-Hill, 2010: 423. Photo contributor: Richard Strait, MD.)
TREATMENT
IV ceftriaxone or cefotaxime is treatment of choice until sensitivities are available.
See Septic Shock.
HUMAN IMMUNODEFICIENCY VIRUS (HIV) IN THE CHILD
ETIOLOGY
Infants: Vertical transmission from mothers either perinatally or through breast milk (preventable with antiretroviral prophylaxis).
Adolescents: Sexual transmission or IV drug use.
Perinatal HIV
Lymphadenopathy
Hepatosplenomegaly
Oral thrush
Failure to thrive
DIAGNOSIS
HIV screening is part of prenatal care.
In non-breast-feeding infants < 18 months of age and born to HIV -infected mothers, definitive exclusion of HIV-1 is based on:
At least two negative HIV-1 DNA or RNA virologic tests, both of which were obtained at ≥ 1 month of age and one of which was obtained at ≥ 4 months of age or
Two negative HIV-1 antibody test results from separate specimens obtained at ≥ 6 months of age and
No other laboratory or clinical evidence of HIV-1 infection, and no AIDS-defining condition for which there is no other underlying condition of immunosuppression.
In adolescents of > 13 years of age, rapid oral swab enzyme immunoassay (EIA) is an alternative method. If it is positive, confirmatory enzyme-linked immunosorbent assay (ELISA) and Western blot are required.
Suspect HIV infection in a child with failure to thrive, oral thrush after 3 months of age, generalized nontender lymphadenopathy, hepatosplenomegaly, and thrombocytopenia.
Common presentation:
Infants: PCP
Children: ITP
Consider acute HIV syndrome in a sexually active adolescent with mononucleosis-like illness with fever, lymphadenopathy, and hepatosplenomegaly.
See Table 10-2 for clinical classifications.
TABLE 10-2. 1993 Centers for Disease Control and Prevention Clinical Classification of HIV Infection in Children < 13 years
TREATMENT
Three classes:
Nucleoside reverse transcriptase inhibitors (NRTIs).
Non-nucleoside reverse transcriptase inhibitors (NNRTIs).
Protease inhibitors.
HIV rapidly becomes resistant; therefore, multidrug therapy is necessary.
COMMON OPPORTUNISTIC INFECTIONS IN HIV
Toxoplasmosis
ETIOLOGY
Toxoplasma gondii (intracellular protozoan).
Cats excrete cysts in feces.
SIGNS AND SYMPTOMS
Mononucleosis syndrome including fever, lymphadenopathy, and hepatosplenomegaly.
Disseminated infection with T cell deficiency.
DIAGNOSIS
Serologic antibody tests, biopsy, visualization of parasites in CSF.
TREATMENT
Pyrimethamine and sulfadiazine used concurrently (both inhibit folic acid synthesis, so replace folic acid).
Cryptococcosis
DEFINITION
Fungal infection.
Primary infection in lungs.
Disseminates to brain, meninges, skin, eyes, and skeletal system in immune compromised.
SIGNS AND SYMPTOMS
Subacute or chronic meningitis is the most common presentation in AIDS.
Typically presents with fever, headache, and malaise.
Postinfectious sequelae commonly including hydrocephalus.
Change in visual acuity.
Deafness.
Cranial nerve palsies.
Seizures.
Ataxia.
DIAGNOSIS
Definitive diagnosis requires isolation of the organism from body fluid or tissue specimens: sputum, bronchopulmonary lavage, or CSF.
Niger seed (birdseed) can ↑ detection in sputum and urine.
The latex agglutination test and EIA for detection of cryptococcal capsular polysaccharide antigen in serum or CSF specimens are excellent rapid diagnostic tests.
Microscopy: Encapsulated yeast seen as white halos when CSF is mixed with India ink.
Can be grown in culture (takes up to 3 weeks).
May also see cryptococcomas on head CT.
TREATMENT
Treat with combination therapy using amphotericin B and flucytosine.
Relapse rate is very high. This is a reason for subsequent maintenance therapy with oral fluconazole.
Pneumocystis jiroveci Pneumonia
Formerly P carinii, now classified as a fungus.
EPIDEMIOLOGY
Peak incidence 3–6 months of age.
Highest mortality rate in infants.
SIGNS AND SYMPTOMS
Acute onset of fever, tachypnea, dyspnea, dry cough, and progressive hypoxemia.
Chest x-ray—diffuse bilateral interstitial infiltrates or alveolar disease, may have characteristic “ground glass” appearance.
DIAGNOSIS
Diagnosis by methenamine silver staining of bronchoalveolar fluid lavage (BAL) to identify cyst walls or Giemsa staining to identify nuclei of trophozoites. LDH > 500.
TREATMENT
First-line treatment with prednisone is trimethoprim-sulfamethoxazole (TMP-SMX) (TMP: 15–20 mg/kg/24 hr; SMX: 75–100 mg/kg/24 hr) q6h for 5–7 days.
Alternative regimens: Pentamidine, TMP-SMX plus dapsone, atovaquone.
PROPHYLAXIS
Starting at 6 weeks of age TMP-SMX if CD4 < 15%, or < 200 for age 6–12 years old and < 500 for age 1–5 years old. Risk displacement of bilirubin in neonate.
Atypical Mycobacterial Infections
ETIOLOGY
Mycobacterium avium complex (MAC).
Considered an AIDS-defining illnesses. Patients with CD4 counts < 50/mm3 are at highest risk.
Rifabutin ↓ serum levels of zidovudine (ZDV) and clarithromycin.
SIGNS AND SYMPTOMS
Disseminated disease:
Fever.
Malaise.
Weight loss.
Night sweats.
May have gastrointestinal (GI) symptoms.
Fluconazole can ↓ the level of rifabutin by 80%.
DIAGNOSIS
Diagnosis by culture from blood, bone marrow, or tissue.
TREATMENT
Two-drug regimen:
Either clarithromycin or azithromycin
Plus ethambutol, rifabutin, rifampin, ciprofloxacin, or amikacin.
Rifabutin can color body secretions such as urine, sweat, and tears a bright orange
PROPHYLAXIS
For CD4 < 50: Azithromycin once a week.
Cytomegalovirus (CMV)
ETIOLOGY
Member of Herpesviridae family.
PATHOPHYSIOLOGY
Infection is lifelong, as with any other herpesvirus. It may be acquired early in life and stay latent until host becomes immunocompromised, years later. Lung, liver, kidney, GI tract, and salivary glands are most common organs infected.
CMV is the most frequently transmitted virus to a child before birth.
SIGNS AND SYMPTOMS
Pneumonitis.
Esophagitis.
Retinitis (can cause blindness).
DIAGNOSIS
Reactivation may be associated with appearance of IgM in serum.
Detection of pp65 antigen in white blood cells is used to detect infection in immunocompromised hosts. Quantitative polymerase chain reaction (PCR) (viral load) in blood is available.
Urine shedding of virus is lifelong. Positive urine CMV culture does not indicate association with current disease.
TREATMENT
Gancyclovir. Addition of intraocular to systemic for retinitis.
IV foscarnet in gancyclovir-resistant infection.
FEVER AND RASH
Enanthema: Lesion(s) on mucosa.
Exanthema: Lesion(s) on the skin, rash.
Polymorphous rash: Consists of various primary elements.
Primary elements of rash:
Macule: Flat, pink blanching spot.
Papule: Small, raised spot.
Vesicle: Small, round fluid-filled lesion.
Pustule: Small, round pus-filled lesion.
Petechia: Pinpoint nonblanching purplish spot (extravasation).
Purpura: Small, raised, purplish nonblanching lesion (extravasation).
Erythroderma: Confluent redness of the skin.
Excoriation: Crust.
Eschar: Dead tissue (or ulcer) covered by dry, dark scab.
In order to recognize infection, keep in mind:
Primary element(s) of rash.
Distribution and/or pattern of the rash.
Sequence (timeline) of events.
Associated hallmarks of infection.
Vaccine-preventable infection is most likely to develop in an unvaccinated child, for example, in a new immigrant or in an adoptee.
Remember: Any rash may be itchy.
See Table 10-3.
Rubeola (Measles)
A 6-year-old girl has a 1-day history of a rash. It started on her face and then spread to the trunk. Prior to developing the rash, she had a 4-day history of running nose, pink eyes with crusting, barking cough, and high fever. She was never immunized because of her parents’ beliefs. On exam, her temperature is 103°F (39.4°C), and there is a maculopapular rash most prominent on the trunk. There are three tiny whitish round spots on her buccal mucosa. Think: Measles.
Measles is characterized by high fever, an enanthem (Koplik’s spots), cough, conjunctivitis, and a maculopapular rash. The rash usually begins on the face and appears several days after the initial symptoms. Koplik’s spots precede the onset of rash.
Rubeola classic findings:
Coryza
Cough
Conjunctivitis
Koplik spots
ETIOLOGY
Paramyxovirus (RNA virus).
SIGNS AND SYMPTOMS
Fever is high and, together with “3Cs” (see Table 10-3), precedes rash (3–5 days).
Conjunctivitis is exudative (yellow discharge).
Cough is croupy (barking, or “seal-like”).
Rash starts as faint macules on upper lateral neck, behind ears, along hairline, and on cheeks.
TABLE 10-3. Fever and Rash
Lesions become maculopapular and spread quickly downward (“shower distribution”), while the rash becomes confluent (erythrthroderma) starting from the top.
May have lymphadenopathy or splenomegaly.
Koplik spots (pathognomonic): Irregularly shaped spots with grayish white centers on buccal mucosa (see Figure 10-2).
DIAGNOSIS
Clinical.
Laboratory rarely needed.
Children under the age of 6 months do not usually get measles due to passive immunity they still have from mother.
COMPLICATIONS
Otitis media.
Pneumonia: May be fatal in HIV patients.
Encephalitis.
TREATMENT
The World Health Organization recommends vitamin A for all children with measles, regardless of their country of residence.
Vitamin A for measles.
VACCINE
Live attenuated vaccine included in measles-mumps-rubella (MMR) vaccine.
Generally given at 12–15 months with a booster given at 4–6 years.
FIGURE 10-2. Koplik spots (rubeola).
(Reproduced, with permission, from Knoop KJ, Stack LB, and Storrow AB. Atlas of Emergency Medicine, 1st ed. New York: McGraw-Hill, 1997: 174.)
Rubella
A 3-year-old girl develops a rash. She was recently adopted from Romania, and her immunization history is unknown. She is brought in because of a fever × 1 day. On physical examination, she is not sick-looking, her temperature is 100.4°F (38.0°C), there is a confluent maculopapular rash on her face and discrete rash on her trunk, and the suboccipital and posterior cervical lymph nodes are palpable. WBC 7.2. Think: Rubella.
The disease has a prodrome of low-grade fever, sore throat, red eyes, headache, malaise, and anorexia. Suboccipital or postauricular lymphadenopathy is common. Rash is usually the first symptom, which appears on the face and spreads centrifugally to the extremities.
Rubella is contagious from 1 week before the rash appears to 1 week after it fades.
ETIOLOGY
RNA virus.
SIGNS AND SYMPTOMS
Mild fever prodrome for 1–2 days.
Rash begins on face and spreads quickly to trunk (“shower distribution”). As it spreads to trunk, it clears on face.
Lymphadenopathy: Retroauricular, posterior cervical, and suboccipital.
Conjunctivitis may be present.
Polyarthritis common in adolescent females.
COMPLICATIONS
Progressive panencephalitis (very rare):
Insidious behavior change.
Deteriorating school performance.
Later, dementia and multifocal neurologic deficits.
Thrombocytopenia (rare).
TREATMENT
Supportive; usually lasts about 3 days.
Congenital Rubella Syndrome
The earlier in gestation rubella occurred, the higher is the risk—more than 80% in the first trimester, and 25% at the end of the second trimester.
Neonatal manifestations:
Intrauterine growth retardation.
Pneumonitis.
Radiolucent bone lesions.
Hepatosplenomegaly.
Thrombocytopenia.
“Blueberry muffin” rash (dermal erythropoiesis).
Eye: Cataracts, glaucoma, pigmentary retinopathy, microphthalmos.
Heart: Patent ductus arteriosus (PDA), peripheral pulmonary artery stenosis.
Sensorineural hearing impairment.
Neurologic: Meningoencephalitis → mental retardation.
VACCINE
Live attenuated vaccine included in MMR vaccine.
Generally given at 12–15 months with a booster given at 4–6 years.
Roseola
An 11-month-old boy has had a fever 103–104°F (39.4–40°C) for 4 days and was seen in ED because of febrile seizures. He had no vomiting, did not look sick, and his neurologic examination was normal. The only finding at the time was small suboccipital lymph nodes. No workup was done. Three days later, the child’s fever has resolved, but now he has a maculopapular rash. Think: Roseola.
Typical history: Rash appears when the fever disappears. It is associated with high fever, and some children may develop a seizure. Mild cervical or occipital lymphadenopathy may be present.
Peak age: 6–24 months
ETIOLOGY
Human herpesvirus types 6 and 7.
By the age of 4 years almost all are immune.
SIGNS AND SYMPTOMS
High fever.
Mild upper respiratory symptoms.
Cervical and suboccipital lymphadenopathy.
Maculopapular rash that spreads to the neck, face and proximal extremities.
The high fever seen with roseola often triggers febrile seizures.
TREATMENT
Supportive (antipyretics, ↑ oral fluid intake, rest).
Fifth Disease (Erythema Infectiosum)
An 8-year-old girl has a 4-day history of fever and bright red cheeks. Now she has rash everywhere and complains of knee pain. On examination, she is not sick-looking, her temperature is 100.8°F (38.2°C), and she has “slapped”-looking cheeks and a discrete macular rash on the trunk and extremities that looks lacy. Her joints look intact, with full range of motion. Think: Erythema infectiosum, Parvovirus B19.
Erythema infectiosum is a self-limiting exanthematous illness in children. Slapped-cheek appearance is classic presentation. In addition, lacy, reticulated appearance on the extremities is often present.
ETIOLOGY
Parvovirus B19.
PATHOPHYSIOLOGY
Attacks red blood cell precursors.
Transmitted in respiratory secretions.
SIGNS AND SYMPTOMS
Prodrome: 1 week of low-grade fever, headache, malaise, myalgia, and mild upper respiratory symptoms.
“Slapped cheeks,” circumoral pallor.
Rash spreads rapidly to trunk and extremities in ornamental “lacelike” pattern.
Arthritis (knee) rare in children.
DIAGNOSIS
Clinical (serum parvovirus B19 immunoglobulin M is available, eg, for arthritis cases).
Parvovirus B19 serology may be offered to women of childbearing age to determine their susceptibility to infection (teachers).
COMPLICATIONS
Transient aplastic crisis in patients with chronic hemolysis including sickle cell disease (SCD), thalassemia, hereditary spherocytosis, and pyruvate kinase deficiency.
Chronic anemia/pure red cell aplasia in immunocompromised hosts.
Hydrops fetalis: Generalized edema due to fetal congestive heart failure (caused by fetal anemia).
TREATMENT
Supportive (antipyretics, ↑ oral fluid intake, rest).
Intravenous immune globulin (IVIG) should be considered for immunocompromised patients.
Scarlet Fever
A 7-year-old boy has a sore throat, fever, and rash. His classmate had similar symptoms 1 week ago. On examination, his temperature is 102°F (38.9°C). He has red tonsils; swollen, tender bilateral anterior cervical lymphatic nodes (2.5 cm); and a confluent red rash that feels “sandpaper-like.” He has circumoral pallor (nasolabial triangle and chin are spared). Think: Scarlet fever.
Scarlet fever has an abrupt onset, with fever, chills, malaise, and sore throat and a distinctive rash that begins on the chest. Circumoral pallor is often present. The rash has a rough, sandpaper-like texture.
Scarlet fever common findings:
Sandpaper rash
Pastia lines
Desquamation
ETIOLOGY
Erythrogenic exotoxins of group A β-hemolytic Streptococcus (GAS).
SIGNS AND SYMPTOMS
Fever, often sore throat.
Confluent erythematous (erythroderma) sandpaper-like rash.
Nasolabial triangle and chin are spared: “Circumoral pallor.”
Accentuation of rash in a linear pattern in folds (Pastia lines).
Desquamation (peeling), starting with fingers, in the second week.
DIAGNOSIS
Clinical.
Throat culture, anti-streptolysin O (ASO), and deoxyribonuclease B titers.
COMPLICATIONS
Myocarditis.
TREATMENT
Penicillin.
Varicella (Chickenpox)
A 5-year-old boy has had a fever for 3 days and an itchy rash that started yesterday. He is a recent immigrant from overseas. On examination, his temperature is 101.8°F (38.8°C) and he does not look sick. There are crops of papules, vesicles, pustules, and crusts on the face, trunk, and extremities. Think: Varicella.
Varicella is a highly contagious disease characterized by a generalized vesicular rash. There is centripetal distribution. In a patient with chickenpox, erythematous macules, papules, vesicles, and scabbed lesions are present at the same time.
DEFINITION
Highly contagious, self-limited viral infection characterized by multiple pruritic vesicles (Figure 10-3).
ETIOLOGY
Varicella-zoster virus (VZV), group of herpesviruses.
EPIDEMIOLOGY
Ninety percent of patients are < 10 years old.
Often, there is a history of exposure to infected individual.
Incidence is ↓ with introduction of vaccine.
PATHOPHYSIOLOGY
Transmitted by respiratory secretions and fluid from the skin lesions.
Virus replicates in respiratory tract.
Establishes lifelong infection in sensory ganglia cells.
Herpes zoster (shingles) is the reactivation of VZV and occurs in dermatomal distribution.
SIGNS AND SYMPTOMS
Rash may be preceded by a prodrome of fever, malaise, anorexia, headache, and abdominal pain 24–48 hours before the onset of the rash.
FIGURE 10-3. Varicella (chickenpox).
Note dewdrop appearance of lesion and that there are lesions in multiple stages of eruption.
“Dew drops on a rose petal” initially appear on face and spread to trunk and extremities, sparing palms and soles.
Within days, vesicles become turbid and then crusted (see Figure 10-3).
DIAGNOSIS
Clinical; Tzanck preparation is not used anymore.
PCR test of swab from the vesicle.
Smallpox generally presents with all lesions in the same stage (versus chickenpox).
COMPLICATIONS
Skin lesions may be superinfected by bacteria (Streptococcus pyogenes or Staphylococcus aureus).
Pneumonia in immunocompromised or pregnant patients.
Encephalitis.
Reye syndrome (associated with aspirin use).
TREATMENT
For most immunocompetent children: Symptomatic for fever and pruritus.
For VZV pneumonia and for immunocompromised individuals: Acyclovir.
Congenital Varicella Syndrome
Caused by maternal varicella infection in first 20 weeks of pregnancy.
Varicella zoster immune globulin (VZIG) is used for post-exposure prophylaxis in immunocompromised or newborns exposed to maternal varicella
SYMPTOMS
Cicatricial skin lesions (cutaneous scarring).
Limb hypoplasia.
Neurologic deficits.
Eye abnormalities.
VACCINE
Live attenuated vaccine, first dose given between 12 and 18 months of age, second dose age > 4 years.
Hand-Foot-Mouth Disease
ETIOLOGY
Enteroviruses: 71, coxsackievirus A16.
EPIDEMIOLOGY
Fecal-oral and respiratory routes.
Summer and fall seasonal pattern.
SIGNS AND SYMPTOMS
GI discomfort.
Ulcerative mouth lesions (small, superficial, round erosions).
Hand and foot lesions tender and vesicular.
Hands more commonly involved than feet.
May occur on palms and soles.
COMPLICATIONS
Aseptic meningitis
Encephalitis
Mumps
An unvaccinated 14-year-old boy presented with fever of 100.9°F (38.3°C), bilateral facial swelling, and inability to eat normally because of pain when he tries to chew. On examination, he was active and had trismus (inability to open wide the mouth) and swelling in front of the earlobes. There was no redness or purulent discharge at Stenson duct openings. At follow-up visit 8 days later, parotid swelling is resolved, but now he has a swollen tender left testis. Think: Mumps orchitis.
Epididymo-orchitis is a common extra–salivary gland complication of mumps in postpubertal males. Many of these occur during the first week of parotitis. It is characterized by marked testicular swelling and severe pain and may be associated with fever, nausea, and headache. Testicular atrophy may follow, although sterility is not common.
ETIOLOGY
Paramyxovirus (RNA virus).
PATHOPHYSIOLOGY
Spread via respiratory secretions.
Incubation period of 14–24 days.
SIGNS AND SYMPTOMS
Rare viral prodrome.
Swelling and tenderness in one or both parotid glands.
Difficult to open mouth.
COMPLICATIONS
Meningoencephalomyelitis (rare).
Orchitis/oophoritis common after puberty.
Pancreatitis.
Arthritis.
Thyroiditis.
Deafness.
VACCINE
Live attenuated vaccine included in MMR vaccine.
Generally given at 12–15 months with a booster given at 4–6 years.
BACTERIAL INFECTIONS
Typhoid (Enteric) Fever
An 8-year-old boy returns from Africa, and 5 days later develops fever that gets higher and higher, escalating in the next 7 days. He has abdominal pain and refuses to eat. His last bowel movement was normal and occurred prior to the onset of fever. On examination, his temperature is 103°F (39.4°C), HR 88 beats/min. There are fine pink spots on the abdomen and a palpable spleen (2.5 cm). Abdomen is soft, with mild, nonconstant tenderness and no guarding or rebound. WBC is 11.9, and blood smear shows no parasites. Think: Typhoid fever.
Typhoid fever is characterized by prolonged sustained fever, relative bradycardia, splenomegaly, rose spots, and leukopenia. It is due to S typhi.
Typhoid fever:
Relative bradycardia
Rose spots
Hepatosplenomegaly
ETIOLOGY
Salmonella typhi.
PATHOPHYSIOLOGY
Fecal-oral transmission.
Incubation period of 7–14 days.
Time of incubation dependent on inoculum size.
SIGNS AND SYMPTOMS
Fever: Gradual rise in the first week, gradual → in the third week.
Malaise.
Anorexia.
Myalgia.
Headache.
Abdominal pain.
Diarrhea is a late symptom.
Transient rose-colored spots on trunk.
Hepatosplenomegaly.
COMPLICATIONS
Intestinal hemorrhage
Intestinal perforation
DIAGNOSIS
Culture of blood, urine, stool.
The sensitivity of blood culture is ~60%.
TREATMENT
Ceftriaxone.
Severe case with altered mental status: Dexamethasone is to be considered.
VACCINE
Available for travelers to endemic areas (not routinely recommended).
Tick-Borne Infections
LYME DISEASE
A 6-year-old boy developed limping, swelling, and pain in his right knee; there was no fever. Two months ago he was hiking in Wisconsin. Physical examination shows temperature of 98.6°F and no distress. No rash/murmur/organomegaly. The right knee was swollen, warm, but not red, with ↓ range of motion due to pain on passive movement. Think: Lyme disease.
Lyme disease:
Erythema migrans
Bell’s palsy
Heart block
An 11-year-old girl presents with an enlarging erythematous, nonitchy spot on her left shoulder. She was camping in upstate New York 2 weeks ago. On examination, her temperature is 100.3°F (37.9°C), she is not sick-looking, and she has a flat annular lesion 7 cm in diameter on the left shoulder. No regional lymphadenopathy is noted. Think: Lyme disease.
Lyme disease is a tick-borne, inflammatory disorder due to the spirochete Borrelia burgdorferi. The most common manifestation of Lyme disease in children is erythema migrans rash and arthritis. Most case of Lyme disease are from the following states: New York, Pennsylvania, New Jersey, Massachusetts, Connecticut, Wisconsin, Maryland, Minnesota, and Delaware
DEFINITION
A multisystem disease transmitted by the bite of an Ixodes tick infected with a spirochetes.
ETIOLOGY
Borrelia burgdorferi.
EPIDEMIOLOGY
Patients are often unaware of the tick bite.
Incubation period: 2–31 days (see Table 10-4).
Keep in mind geography (presence of a vector) and season (see Table 10-5).
PATHOPHYSIOLOGY
Disseminated Lyme is due to a spirochetemia.
TABLE 10-4. Stages of Lyme Disease
TABLE 10-5. Epidemiology of Tick-Borne Infections
SIGNS AND SYMPTOMS
See Table 10-4.
Erythema migrans (EM):
Begins as a red macule or papule that gradually (over days to weeks) turns into an annular, erythematous lesion of 5–15 cm in diameter (Figure 10-4).
Sometimes there is partial central clearing (halo appearance).
May have vesicular or necrotic areas in its center and can be confused with cellulitis.
The lesion usually is painless and not pruritic.
May be located at the axilla or in the groin.
May be associated with acute onset of fever, chills, myalgia, weakness, headache, and photophobia.
Isolated facial palsy (CN VII, Bell’s palsy): Develops 3–5 weeks after exposure.
Treatment has no effect on resolution, but prevents late events (arthritis).
Self-limited.
DIAGNOSIS
Confirmed by serology.
During the first 4 weeks of infection, serologic tests are negative and therefore not recommended.
Immunoglobulins M and G (IgM and IgG) peak 4–6 weeks after exposure and are detected by EIA (screening, may be false positive) and Western immunoblot (confirmation).
False-positive results with other spirochetal infection and in patients with some autoimmune disorders (systemic lupus erythematosus [SLE], rheumatoid arthritis [RA]).
An elevated IgG titer in absence of an elevated IgM indicates prior exposure as opposed to recent infection.
PCR can detect spirochete DNA in CSF and synovial fluid.
Forty percent of skin biopsies reveal spirochetes.
FIGURE 10-4. Erythema chronicum migrans rash characteristic of Lyme disease.
COMPLICATIONS
Sixty percent of untreated cases with disseminated infection develop arthritis (mediated by immune complex formation) 6 weeks following tick bite.
TREATMENT
Amoxicillin (cefuroxime) or doxycycline:
EM: 14–21days.
Multiple EM: 21 days.
Isolated facial palsy: 21–28 days.
Arthritis: 28 days.
Ceftriaxone or Penicillin IV: Carditis, meningitis, persistent/recurrent arthritis: 14–28 days.
If untreated, lesions fade within 28 days. If delayed diagnosis, may have permanent neurologic or joint disabilities.
ROCKY MOUNTAIN SPOTTED FEVER (RMSF)
An 8-year-old girl from North Carolina presents with fever, severe headache, and myalgia over 3 days in July. She attended a family picnic 1 week ago. On examination, she has a temperature of 102.9°F (39.4°C), HR 134 beats/min. She is complaining of headache and has a macular rash on the wrists, palms, ankles, and soles. There are no other significant findings. Her platelets are 68 and serum sodium is 129. Think: Rocky Mountain spotted fever.
RMSF is a systemic tick-borne illness caused by Rickettsia rickettsii. Rash is considered the hallmark of this disease, which characteristically involves the palm and soles. Severe frontal headache is common, although it occurs less frequently in children. Abdominal pain, splenomegaly, and conjunctivitis may also be present. RMSF should be considered in the following states: Oklahoma, North and South Carolina, Tennessee, and Pennsylvania. Highest incidence rates for RMSF are in North Carolina and Oklahoma. Since the classic triad of fever, rash, and a history of tick exposure occurs in a few patients, awareness of seasonality and geographic distribution of the disease is important to make the diagnosis. Laboratory abnormalities include hyponatremia, hypoalbuminemia, anemia, and thrombocytopenia.
If treated adequately, lesions fade within days and the late manifestations are prevented.
DEFINITION
A potentially life-threatening disease following a tick bite.
ETIOLOGY
Rickettsia rickettsii.
EPIDEMIOLOGY
Keep in mind geography (presence of a vector) and season (see Table 10-5).
PATHOPHYSIOLOGY
An intracellular infection of the endothelial cells lining the small blood vessels, resulting in vascular necrosis and extravasation of blood.
Only 60% of patients report a history of a tick bite.
The incubation period is 2–14 days.
Rarely occurs in the Rocky Mountains.
Highest incidence in children aged 5–10 years old.
SIGNS AND SYMPTOMS
Sudden onset of high fever, myalgia, severe headache, rigors, nausea, and photophobia.
Fifty percent develop rash within 3 days. Another 30% develop the rash within 6 days.
Rash consists of 2- to 6-mm pink initially blanchable macules that first appear peripherally on wrists, forearms, ankles, palms, and soles.
Within 6–18 hours the exanthem spreads centrally to the trunk, proximal extremities, and face (centrifugal).
Within 1–3 days the macules evolve to deep red papules, and within 2–4 days the exanthem is hemorrhagic and no longer blanchable.
Up to 15% have no rash (“spotless”).
Many patients have exquisite tenderness of the gastrocnemius muscle.
Meningitis is common.
If untreated, myocarditis, disseminated intravascular coagulation (DIC), shock, fatality rate up to 25%.
DIAGNOSIS
Clinical.
Rash biopsy would demonstrate necrotizing vasculitis.
Indirect fluorescent antibody (IFA) assay: Titer > 1:64 is diagnostic.
TREATMENT
Doxycycline, irrespective of a patient’s age.
COMPLICATIONS
Fulminant infection in glucose-6-phosphate dehydrogenase (G6PD) deficiency.
Noncardiogenic pulmonary edema.
Meningoencephalitis.
Multiorgan damage due to vasculitis.
RMSF is a clinical diagnosis. It is important not to delay treatment.
Toxic Shock Syndrome
DEFINITION
An acute, febrile, exanthematous illness that involves multiple systems with potential complications, including shock, renal failure, myocardial failure, and adult respiratory distress syndrome.
PATHOPHYSIOLOGY
A result of hematogenous dissemination of a toxin.
Toxins from Staphylococcus or Streptococcus (Table 10-6) act as superantigens activating T cells, resulting in massive release of cytokines, which has profound physiologic consequences (ie, fever, vasodilation, hypotension, and multisystem organ involvement).
RMSF is one of the few current indications to use chloramphenicol. It is seldom used anymore due to potential for gray baby syndrome (aplastic anemia).
TABLE 10-6. Diagnostic Criteria of Toxic Shock Syndrome (TSS)
SIGNS AND SYMPTOMS
Sick-looking patient—streptococcal TSS (group A Streptococcus [GAS]): Usually, there is evidence of soft tissue infection (Table 10-7), classically necrotizing fasciitis in a patient with varicella.
Less than half of staphylococcal TSS is associated with menstrual tampons. Source also may be nasal or wound packing, or an abscess.
Recovery in 7–10 days.
TREATMENT
Aggressive fluid replacement.
Eradication of source.
Parenteral β-lactamase-resistant antibiotic.
TABLE 10-7. Streptococcal versus Staphylococcal
FUNGAL INFECTIONS
See Table 10-8 for a summary of endemic fungal infections.
TABLE 10-8. Summary of Endemic Fungal Infections
Coccidioidomycosis
A 13-year-old girl develops fever, cough, and chest pain soon after she has visited relatives in Arizona, where they were outing in a desert quite often. On examination, her temperature is 102.5°F (39.2°C), RR 44 breaths/min, no hypoxemia, and rales are heard over her left lower lobe. There are symmetrical tender, red, shiny indurations on both shins. WBC: 16.8. Chest radiograph shows left lower lobe consolidation. Think: Coccidioidomycosis.
Coccidioidomycosis is an infectious disease caused by the fungus Coccidioides immitis. Also known as San Joaquin Valley fever, coccidioidomycosis should be considered in southwestern U.S. states (Arizona, California, New Mexico, Utah, Nevada, and Texas). Symptoms usually develop 1–3 weeks after exposure. Clinical features include dry cough, chest pain, myalgias, arthralgia, fever, anorexia, and weakness.
ETIOLOGY
Coccidioides immitis, the dimorphic fungus.
EPIDEMIOLOGY
Southwestern United States.
Black and Filipino, pregnant women, neonates, and immunocompromised people have higher risk of dissemination.
Person-to-person transmission does not occur.
Incubation period: 1–3 weeks.
Transmission: Inhalation of airborne spores.
Infection produces lifelong immunity.
SIGNS AND SYMPTOMS
Usually asymptomatic or self-limited: Influenza-like or pneumonia, with fever, headache, cough, malaise, myalgia, and chest pain.
Maculopapular rash, erythema multiforme, or erythema nodosum may be the only manifestations.
Dissemination is rare, mostly in infants: Skin, bones and joints, central nervous system (CNS), and lungs.
Night sweats and anorexia.
Meningitis almost invariably is fatal if untreated.
DIAGNOSIS
Residual coin-like pulmonary lesions may be present on chest x-ray.
Spherules with endospores in tissue or body fluid is pathognomonic.
Cultures are hazardous.
Elevated erythrocyte sedimentation rate (ESR) and alkaline phosphatase.
Marked eosinophilia.
TREATMENT
Same as for histoplasmosis below.
Surgery for chronic pulmonary coccidioidal disease that is unresponsive to IV azole or amphotericin B therapy.
Histoplasmosis
A 6-year-old boy from Indiana develops fever, chest pain, and cough. He was playing in a cave 10 days ago and got scared of bats. Physical exam shows no distress, temperature of 100.7°F (38.2°C), RR 28 breaths/min, oxygen saturation 95%. Rhonchi are heard over the lung fields bilaterally. WBC: 14.9. Chest x-ray shows diffuse bilateral reticulonodular infiltrates and hilar lymph node. Think: Histoplasmosis.
It is the most common endemic mycosis causing human infection. Pneumonia is the most common presentation. Atypical pneumonia is usually the initial diagnosis. Initial chest x-ray may show patchy infiltrate, while diffuse reticulonodular infiltrates are present in a progressive disease. The presence of hilar or mediastinal lymphadenopathy ↑ the suspicion for fungal pneumonia.
ETIOLOGY
Histoplasma capsulatum.
EPIDEMIOLOGY
Endemic infection: Ohio and Mississippi River valleys.
History of exposure to bird or bat droppings.
Incubation period: 1–3 weeks.
Transmission: Inhalation of airborne spores.
Reinfection happens with large inoculum.
SIGNS AND SYMPTOMS
Generally asymptomatic
Flulike prodrome.
The more spores inhaled, the more symptoms.
Severe acute pulmonary infection: Diffuse nodular infiltrates, prolonged fever, fatigue, and weight loss.
Progressive disseminated histoplasmosis (PDH): In infants < 2 years of age and in immunosuppressed, often starts as prolonged “fever of unknown origin.”
DIAGNOSIS
Mediastinal adenitis or granuloma may be seen on chest x-ray.
Cultures: Sputum, blood, bone marrow; may be negative.
Histoplasma antigen assay: Cross-reaction with other endemic fungi.
TREATMENT
Uncomplicated infection in an immunocompetent child is self-limited, and does not require treatment.
Oral itraconazole for serious focal (pulmonary) infection.
IV amphotericin B for PDH.
In order to recognize endemic infection, keep in mind:
PROTOZOAL INFECTIONS
Schistosomiasis
A 16-year-old male presents with fever, arthralgia, cough, abdominal pain, and rash of 5 days’ duration. He went to Puerto Rico for a river rafting trip 3 weeks ago. On examination, his temperature is 102°F (38.9°C), there are scattered urticaria on the trunk and extremities that wax and wane, and his spleen is palpable 3 cm below the costal margin. WBC count is 6.1, with 23% eosinophils. Think: Schistosomiasis.
Schistosomiasis is transmitted in tropical and subtropical areas. Clinical presentations are chills, cough, abdominal pain, diarrhea, nausea, vomiting, headache, rash, and lymphadenopathy. Physical examination may show an enlarged, non-tender liver and an enlarged spleen. Eosinophilia is often prominent in schistosomiasis.
ETIOLOGY
Caused by trematodes (flukes). See Table 10-9.
TABLE 10-9. Schistosomiasis
EPIDEMIOLOGY
Fecal or urine ova get into the snails and form larvae.
Larvae leave the snail into the fresh water and penetrate the skin.
Larvae travel to particular organs and tissues, and there develop into mature forms.
SIGNS AND SYMPTOMS
“Swimmer’s itch” transient, a few hours after water exposure, followed in 1–2 weeks by an intermittent pruritic, papular rash.
Invasive stage: Within weeks to months of exposure—fever, malaise, cough, abdominal pain, and nonspecific rash .
Ulceration of intestine and colon, abdominal pain, and bloody diarrhea (Schistosoma interclatum and Schistosoma mekongi).
Pay attention to travel history and timing from return (incubation period from weeks to months).
DIAGNOSIS
Eggs in stool or urine.
Eosinophilia.
TREATMENT
Praziquantel.
Exposure to fresh water (lake, river) at the endemic area: swimming, fishing, playing.
Visceral Larva Migrans
ETIOLOGY
Toxocara canis and Toxocara cati (roundworms of puppies or kittens).
EPIDEMIOLOGY
Fecal-oral transmission: Eggs in soil make their way into the mouth by getting onto hands or toys.
Role of pica—eating soil: Ingested eggs hatch and penetrate the GI tract, migrating to the liver, lung, eye, central nervous system, and heart, where they die and calcify.
Differentiate eye lesions of visceral larva migrans from retinoblastoma.
SIGNS AND SYMPTOMS
Most individuals are asymptomatic.
Symptomatic in young children (under 4 years of age).
The more larvae, the more symptoms.
Visceral: Fever, cough, wheezing (pneumonitis), hepatomegaly.
Rare: Myocarditis, encephalitis (seizures).
Ocular: Endophthalmitis or retinal granulomas, usually in older children or adolescents.
DIAGNOSIS
Leukocytosis and hypereosinophilia.
Hypergammaglobulinemia and ↑ titers of isohemagglutinin to the A and B blood group antigens.
EIA for Toxocara antibodies. EIA is more sensitive in visceral than in ocular form of infection.
TREATMENT
Albendazole.
A 4-year-old boy presents with fever and cough of 10 days’ duration. On exam, he has a temperature of 101.8°F (38.8°C) and hepatomegaly. He has leukocytosis, with 45% eosinophils. He likes to play with his puppy in a sandbox. What is the diagnosis? Visceral larva migrans.
TRAUMATIC INFECTIONS
Animal Bites/Scratches
Cleaning, debridement, and irrigation are most important treatment.
Antibiotic prophylaxis for human, cat, and dog bites (amoxicillin/clavulanate).
X-ray to check for bone involvement if deep wound.
Most wounds should not be sutured; if deep wounds, surgical consult is best.
Assess risk for rabies: Local epidemiological information.
Ensure tetanus immunization is up to date.
Pathogens in bites:
Human: Eikenella corrodens
Cats: Pasteurella multocida
Dogs: Capnocytophagia canimorsus
Abrasions and Lacerations
A 10-year-old boy steps on a dirty nail that punctures his foot through his sneaker. Two days later he presents with pain, swelling, and redness of the heel, with purulent drainage from a central pinpoint opening. He has no fever. WBC is 14.6. X-ray: no foreign body, no fracture, no gas in the soft tissue. Think: Wound likely to become infected with Pseudomonas. The association of Pseudomonas infection with puncture wounds to the foot is well recognized.
Cleaning, debridement, and irrigation are most important initial treatment. Suturing indicated if no obvious signs of infection.
If secondarily infected, debride and drain.
Initial antibiotic given based on most likely organism; Gram stain and culture to determine best antibiotic in chronic or complex wounds.
Staphylococcus and Streptococcus are the most common pathogens, so a first-generation cephalosporin such as cephalexin or clindamycin is commonly given as empiric treatment.
In human bites, consider child abuse and risk for HIV and hepatitis B.