Pediatric Examination and Board Review (185 page)

6.
(A)
Malassezia furfur
also can cause a chronic folliculitis in immunocompromised persons, such as with acquired immunodeficiency syndrome. In addition, systemic
Malassezia
infection can cause fungemia in infants receiving parenteral nutrition that contains intralipids. Fever, apnea, and bradycardia, interstitial pneumonia, and thrombocytopenia are common associated findings.

7.
(B)
Primary infection occurs through inhalation of airborne particles. After inhalation, the organism disseminates from the lungs to other organs, the most important being the CNS. Dissemination of the fungus is rare in children without defects in cellmediated immunity. CD4+ lymphocytes have been shown to play an important role in containing CNS infection caused by
Cryptococcus
. Infection with
Cryptococcus neoformans
in the pediatric or adolescent age group should prompt an evaluation for HIV.

8.
(B)
Trimethoprim-sulfamethoxazole is the drug of choice for treatment. Clindamycin plus primaquine has been used for treatment in adults. Prednisone is recommended as adjunctive therapy for moderate to severe
P jiroveci
infection.

9.
(E)
Tuberculous meningitis is most common in children 6 months to 4 years old. Meningitis can occur within 2-6 months of the initial infection. Chest radiographs are normal in 50%, and the Mantoux test is nonreactive in 40% of children with tuberculous meningitis. A CT scan of the brain can be useful to detect basilar enhancement, communicating hydrocephalus, and signs of cerebral edema (
Table 104-1
). Hydrocephalus secondary to meningeal cysticercosis is rare, and cryptococcal meningitis is also not associated with hydrocephalus. Lymphocytic choriomeningitis virus can cause congenital infection characterized by chorioretinitis, hydrocephalus, and microcephaly. Intracranial calcifications are also typically present. Infection with lymphocytic choriomeningitis virus can also be acquired after contact with mice or hamsters.

10.
(
D
) Congenital tuberculosis is rare. A pregnant woman with isolated pulmonary tuberculosis is unlikely to infect her infant until after birth. If congenital tuberculosis is suspected, a Mantoux test, chest radiograph, and lumbar puncture should be performed and antituberculous therapy started. The placenta should be sent to pathology and cultured for
M tuberculosis
.

TABLE 104-1
Characteristic Features of Tuberculous Meningitis in Children

Abbreviations: CSF, cerebrospinal fluid; CT, computed tomography.

11.
(A)
All of the bacteria listed can cause disseminated infection in children with AIDS, but infection with nontuberculous mycobacteria, particularly
M avium
complex (MAC), is most common. The risk of developing disseminated MAC infection is inversely related to the CD4+ count. The incidence is as high as 24% in children with CD4+ counts less than 100 cells/mm
³
. Manifestations of disseminated MAC infections include fever, weight loss, night sweats, abdominal pain, diarrhea, anemia, and neutropenia.

12.
(B)
Lymphadenitis or scrofula is the most common manifestation of nontuberculous mycobacterium (NTM) infection. Lymphadenitis caused by nontuberculous mycobacteria is usually unilateral and involves the submandibular or anterior cervical lymph nodes. For NTM lymphadenitis in healthy children, complete surgical excision is curative.

13.
(D)
Although EIA often provides rapid results, this method is not commercially available for
Giardia
. The other methods listed are more readily available, and examination of a duodenal specimen should be considered when the organism is not found on repeated stool examination but clinical suspicion is high. Infection can occur either by hand to mouth transfer of cysts from feces of an infected person or ingestion of fecally contaminated food or water. Asymptomatic infection is common. Most community-wide epidemics have occurred secondary to a contaminated water supply.

14.
(E)
Lymphadenopathy is frequently found in the cervical area of the neck. The classic triad of congenital toxoplasmosis is chorioretinitis, cerebral calcifications, and hydrocephalus. Humans develop infection with
T gondii
in several scenarios. These include consumption of raw or undercooked meat that contains cysts, accidental ingestion of oocysts from soil, contaminated food, or contact with cat feces.

15.
(D)
T vaginalis
is a common sexually transmitted organism. In addition to the signs and symptoms described, abdominal pain can occur. This may indicate severe vaginitis, but pelvic inflammatory disease should also be considered. In males, urethritis occurs with more than half of patients having urethral discharge. Neonates can develop infection after a vaginal delivery. Symptomatic infection in the female neonate involves a self-limited vaginal discharge.

16.
(B)
In children, infection with
T canis
begins with ingestion of embryonated eggs. This occurs when children are playing in sandboxes and playgrounds contaminated with cat or dog feces. Other clinical manifestations of VLM include lower respiratory tract symptoms such as bronchospasm that mimics asthma. If the
T canis
larvae invade the eye, the results is ocular larval migrans (OLM). The retina can be involved with loss of vision. The raccoon roundworm,
Baylisascaris procyonis
, rarely can cause infection in children, can result in severe encephalitis, and can be acquired from raccoon feces in a sandbox.

17.
(
B
) Each
Plasmodium
species that causes malaria has a distinct geographic distribution.
P ovale
occurs most often in West Africa. Malaria attributable to
P vivax
and
P falciparum
is common in Southeast Asia, Oceania, and South America.
P falciparum
is prevalent in Africa, Haiti, and Papua New Guinea.
P malariae
has the same distribution but is less common than
P falciparum
. Relapses may occur in
P vivax
and
P ovale
because of a persistent hepatic stage of infection.

18.
(B)
In approximately 10% of patients with invasive
Entamoeba histolytica
infection, a liver abscess develops. An ameboma is a mass of granulation tissue in the cecum or ascending colon. The clinical presentation usually includes a tender and palpable abdominal mass. Other organ system involvement is uncommon.

S
UGGESTED
R
EADING

Mandell GL, Bennett JE, Dolin R.
Mandell
,
Douglas and
Bennett’s Principles and Practice of Infectious Diseases
. 7th ed. Philadelphia, PA: Churchill Livingstone; 2010.

Pickering LK, Baker CJ, Kimberlin DW, Long SS.
Red Book
:
2009 Report of the Committee on Infectious Diseases.
28th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2009.

CASE 105: A 4-YEAR-OLD BOY WITH FEVER AND A NECK MASS

A 4-year-old boy is brought to your office for evaluation of a right-sided neck mass. The child was well until about 10 days ago when he developed fever and a rightsided neck swelling. The swelling has increased in size over the past week and is painful. There has been no cough, sore throat, or rhinorrhea. There has not been contact with anyone who has been ill. There also has not been any history of travel.

On physical examination the child is alert, active, and nontoxic in appearance. The temperature is 102.7°F (39.3°C). There are 3 × 4 cm and 1 × 2 cm right posterior cervical triangle lymph nodes. The nodes are movable, firm, and tender to palpation. There are no skin lesions. Examination of the heart and lungs is normal. The leukocyte count is 8900/mm
³
, the hemoglobin is 9.5 g/dL, and the platelet count is 300,000/mm
³
.

SELECT THE ONE BEST ANSWER

1.
In obtaining further history you find out there has been no contact with an adult who has a chronic cough or any exposure to ticks or rabbits. The mother does tell you that their family cat had kittens about 3 months ago. The most likely etiologic agent of this child’s illness is

(A)
Bartonella henselae

(B)
Blastomyces dermatitidis

(C)
Francisella tularensis

(D)
Mycobacterium tuberculosis

(E)
Toxoplasma gondii

2.
The diagnosis in this 4-year-old child can be confirmed most readily by

(A) culture of blood

(B) culture of lymph node specimen

(C) special stains of lymph node specimen

(D) serology

(E) an antigen skin test

3.
Treatment of the infection in this 4-year-old should include

(A) surgical excision of the lymph nodes

(B) no antimicrobial therapy

(C) doxycycline by the oral route

(D) cefazolin

(E) parenteral gentamicin