ScabiesA. Overview. Caused by mite, Sarcoptes scabiei, that burrows in the skin. Most common in children but found in all ages. Usually transmitted by person-to-person transmission but may be picked up from bedding, clothes, etc. B. Diagnosis. Characterized by linear burrows (pathognomonic), papules, or nodules with or preceded by intense pruritus, especially at night. Secondary findings include excoriations, crusting, eczematous plaques, and impetigo. In older children and adults, areas of involvement are webs of fingers, axillae, flexures of arms and wrists, belt line, and areas around the umbilicus, nipples, genitals, and lower buttocks. In infants, palms, soles, head, and neck are involved. Confirm with scraping of lesion with scalpel blade placed on slide with mineral oil and look for mites, ova, or fecal pellets.C. Treatment. Permethrin cream 5% is drug of choice applied head to toe at bedtime and washed off in morning (8 to 14 hours). Alternative is lindane lotion 1% applied to cool, dry skin at bedtime, washed off in morning, and repeated in 1 week. Neither should be used in infants <2 months of age or in pregnant or nursing women; instead use precipitated sulfur (6%) in petroleum applied for three consecutive nights. Family members should be treated even if symptomatic. Bed linens and clothing should be washed in hot water (>120° F) or stored in tightly sealed bags for 1 week. Recently, Meinking et al. reported the use of a single dose of ivermectin 100 mg as effective treatment for scabies, but this is not an approved indication.
