Pocket Emergency Medicine (Pocket Notebook Series) 3rd Ed.

PARASITIC INFECTIONS

SCABIES

History

• Persistent pruritus, worsen over 2–3 wk; sometimes multiple family members involved

• More common in fall & winter months, worse at night

Findings

• Skin eruption: Elevated thin pink or gray track in skin w/ small vesicle at tip

• Associated intense pruritus b/w web spaces of extremities, genital region, axilla, feet, buttocks, areola, nipples, abdomen, beneath breasts

• Secondary lesions include urticaria, impetigo, eczematous plaques, pyoderma, excoriations, cellulitis, & furuncles

Evaluation

• Clinical Dx; burrow ink test, tetracycline fluorescence test, skin scrapings, or shave biopsy

Treatment

• Symptomatic relief, treat secondary infections & household members, clean clothes

• Permethrin 5% cream most effective; if severe can also give ivermectin, lindane 1%

Disposition

• D/c w/ instructions for household to be treated, decontaminate clothing, bedding

• Exclude from school until treated, topical permethrin usually effective w/i 12 h

Pearls

• Caused by female human mite, S. scabiei

• Skin-to-skin contact, indirect contact through bedding or clothing

• Can lead to long-term colonization of skin by group A Strep

TOXOPLASMOSIS

History

• Immunocompromised (HIV), painless impaired vision

Findings

• Mainly neural & muscular tissue involvement, often asymptomatic

• Nontender isolated cervical or occipital LAD, 4–6 wk

• Congenital: Intracranial calcifications, neonatal hydrocephalus, chorioretinitis, blindness

• Immunocompromised: HA, confusion, sz, AMS, focal motor deficits, CN abnormalities, movement disorder

Evaluation

• IgG detection via ELISA

• MRI better than CT to see Toxoplasma brain lesions

Treatment

• Fluid resuscitation, sz tx, airway management

• Nonpregnant: Pyrimethamine + sulfadiazine OR spiramycin OR clindamycin OR azithromycin OR atovaquone + folic acid; corticosteroids for ocular toxoplasmosis

• Pregnant: Spiramycin + pyrimethamine + sulfadiazine

• AIDS: Pyrimethamine + sulfadiazine (tx & prophylactic)

Disposition

• Depends on sxs

Pearls

• Caused by Toxoplasma gondii, an obligate intracellular (in macrophage) sporozoan

• Intracellular parasite; cats are definitive host, mammals serve as intermediate host

• Transmitted via airborne spores or infected food (raw meat, unwashed vegetables, dairy)



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