What kills the tick that causes demodicosis? - briefly
Systemic and topical acaricides—including ivermectin, milbemycin oxime, selamectin, and amitraz—effectively eradicate the Demodex mite that causes demodicosis.
What kills the tick that causes demodicosis? - in detail
The organism responsible for demodicosis is a microscopic Demodex mite that inhabits hair follicles and sebaceous glands. Effective eradication relies on agents that disrupt the mite’s cuticle, interfere with its nervous system, or create an inhospitable environment.
Topical preparations with proven acaricidal activity include:
- Permethrin 5 % cream or lotion – acts on voltage‑gated sodium channels, causing paralysis and death of the mite.
- Benzoyl peroxide 5–10 % gel – oxidizes cellular components, leading to rapid mite mortality.
- Sulfur ointment (3–5 %) – generates hydrogen sulfide, toxic to the parasite and reduces bacterial colonisation.
- Tea tree oil (0.5–1 % solution) – contains terpinen‑4‑ol, which penetrates the cuticle and impairs respiration.
Systemic options, reserved for extensive or refractory cases, are:
- Ivermectin (oral, 200 µg/kg single dose, repeat after 1–2 weeks) – binds to glutamate‑gated chloride channels, inducing paralysis throughout the mite’s body.
- Metronidazole (oral, 15–30 mg/kg/day in divided doses) – exerts anti‑anaerobic and anti‑inflammatory effects, indirectly suppressing mite proliferation.
- Oral azithromycin (10 mg/kg/day for 5 days) – reduces secondary bacterial overgrowth, limiting the mite’s nutrient supply.
Adjunctive measures enhance treatment success:
- Regular cleansing of affected skin with mild, non‑comedogenic soaps – removes excess sebum that serves as food for the parasite.
- Daily eyelid hygiene for ocular involvement – uses diluted baby shampoo or commercial lid scrubs to mechanically dislodge mites.
- Environmental decontamination – washing bedding, towels, and personal items at 60 °C eliminates residual organisms.
Monitoring response involves counting mites in standardized skin scrapings or microscopic examination of eyelash samples. A decline of >90 % within two weeks indicates adequate control; persistence warrants escalation to systemic therapy or combination regimens.
In summary, eradication of the demodicosis‑causing mite requires a multimodal approach: potent topical acaricides, judicious systemic agents when necessary, and strict hygiene practices to prevent reinfestation.