phthirus pubis
• | “crabs”; axillary, pubic, eyelash hair |
pediculosis humanis corporis
• | vector for three diseases – epidemic typhus, trench fever, relapsing fever |
• | transmits through defecation |
pediculosis humanis capitis
• | intense pruritis of the scalp; often only the nits are seen |
• | all lice live by sucking blood from the human host every 3 to 6 hours |
• | obligate parasites of humans, (head lice can survive away from host for ~ 3 days) |
• | nits – hatch 8 to 10 days |
Treatment:
• | permethrin 1% (Nix) apply to dry scalp for 5 to 10 minutes; then rinse off; repeat 1 week |
• | malathion 0.5% (Ovide) apply to dry scalp 8 to 12 hours; rinse off; repeat in 1 week |
• | resistant cases: Rx permethrin 5% cream (Elimite) (overnight, under shower cap) |
• | Eurax works well for resistant pubic lice |
• | pediculosis pubis (especially when on eyelashes) - petrolatum ointment 2 to 4X / day for 8 to 10 days |
instructions for topical treatment:
• | apply after shampooing without conditioner; to thoroughly dry hair |
• | do not shampoo again for 24 hours |
• | re-treatment in a week is necessary, since no treatment is ovicidal |
• | nit removal (combing with a nit comb) should be meticulous in the week between treatments |
• | resistant cases: ivermectin 250 µg/kg single dose |
• | children: <15kg = don’t use ivermectin; 15-24kg = 3mg tab X1; 25-35kg = 6mg tab X1; >35kg = adult dose |
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