What kills a tick during scabies? - briefly
Topical permethrin (5 % cream) and oral ivermectin are the agents that eliminate both the scabies mite and any attached tick. Both disrupt the arthropod’s nervous system, causing rapid paralysis and death.
What kills a tick during scabies? - in detail
Scabies results from infestation by the Sarcoptes scabiei mite, not by ticks. Consequently, the agents that eradicate the organism in this condition are acaricidal medications designed for mites. The most widely used topical preparation is 5 % permethrin cream, which disrupts sodium channels in the mite’s nervous system, leading to paralysis and death within hours of contact. Application to the entire body surface, left on for 8–14 hours, and repeated after one week, eliminates the parasite in the majority of cases.
Oral ivermectin, a macrocyclic lactone, binds to glutamate‑gated chloride channels, causing hyperpolarization of neuronal membranes and rapid paralysis of the mite. A single dose of 200 µg/kg is effective for most patients; a second dose administered 7–10 days later addresses newly hatched mites that were not exposed to the initial treatment.
Additional topical agents include:
- Benzyl benzoate 10–25 %: penetrates the exoskeleton, disrupts lipid membranes, and kills mites within 24 hours; requires repeated applications.
- Crotamiton 10 %: interferes with mite metabolism; less potent than permethrin but useful for patients unable to tolerate other agents.
- Sulfur ointment 5–10 %: acts as a mild irritant, impairing mite respiration; safe for infants and pregnant women, though treatment duration is longer.
Adjunctive measures such as thorough washing of clothing, bedding, and towels at ≥ 60 °C or sealing items in plastic for two weeks prevent re‑infestation. Antihistamines or low‑dose corticosteroids may relieve pruritus, but they do not affect the parasite.
If a tick bite is mistakenly associated with scabies, the appropriate response is removal of the tick and, when indicated, prophylactic antibiotics (e.g., doxycycline) for tick‑borne infections. This protocol is distinct from scabies treatment and does not involve the acaricidal drugs listed above.