0071643192.pdf

INFECTIOUS DISEASE

Cocci—California

Histo—Ohio

Blasto—Bordering Great

Lakes

■ Acute or chronic pneumonia
■ Disseminated disease
■ Reactivation possible in immunocompromised

A 3-year-old boy presents with nightly perianal itching and a normal physical

exam. What is the most likely diagnosis?

Pinworm (Enterobius vermicularis).

COMMON PARASITIC HELMINTHS

■ Most cause eosinophilia.
■ Most helminths are uncommon within the continental United States,
with the exception of E. vermicularis(prevalence ~10% in some studies).
■ Other less commonly identified helminths (mainly in rural southeast
United States) include hookworm (1.5%), Trichuris trichiura(1.2%),Ascaris
lumbricoides(0.8%), Strongyloides stercoralis (0.4%), Hymenolepis nana
(0.4%), and Taeniaspecies (0.1%).

Intestinal Nematodes (Round Worms)

■ Worldwide distribution (see Table 8.14)
■ Treat with mebendazole, albendazole, or pyrantel pamoate.
■ Pulmonary symptoms (ie, Löeffler syndrome, including cough, wheezing,
and pulmonary consolidations) due to worm migration through the lungs
may be seen in infections with Ascaris, hookworm, Strongyloides.

TABLE 8.14. Intestinal Nematodes

NAME NEMATODE ROUTE SYMPTOMS/EXAM DIAGNOSIS

Pinworm E. vermicularis Fecal-oral (most commonly Nocturnal perianal itching Scotch-tape swab

among children)

Common A. lumbricoides Ingestion Pneumonitis, abdominal cramps, O&P

roundworm worm passage (~30 cm long),

obstruction

Hookworm Ancylostoma Soil contact (ie, bare feet) Localized dermatitis (normally O&P

duodenale feet), pneumonitis, abd pain,

Necator americanus anemia

Whipworm T. trichiura Ingestion, soil contact, Dysentery, tenesmus, rectal O&P

flies on food prolapse

Strongyloides S. stercoralis Soil contact, ingestion Eosinophilia, perianal rash, abd Serology, O&P

pain,overwhelming infection

in immunosuppressed

Trichinella Trichinella sprialis Ingestion of raw pork, Fever, periorbital edema, Serology, muscle

walrus, or bear myalgias, CNS abnormalities biopsy