Lice

Identify exclusion criteria for the self-treatment of head lice and know when patients can self-treat

• Allergy

  • Chrysanthemums or pyrethrins (synergized pyrethrins)

  • Ragweed (potential cross sensitivity with synergized pyrethrins)

  • Pyrethrins (permethrin)

• Presence of secondary infection in affected area

• Age

  • <2 months for permethrins

  • <2 years for pyrethrins

• Eyebrow or eyelid infestation

• Pregnancy/breastfeeding

• Presence of active tumors

• Regional resistance to pediculicides

Nonpharmacological recommendations

• Careful visual inspection of hair for nits, combing hair with nit comb

• Avoid direct physical contact, use of shared items

• Washing clothing, bedding in hot water and dried in clothes dryer OR sealing in plastic bag for 2 weeks

• Washing shared items in very hot water

• Carpets, rugs, furniture should be vacuumed regularly 

Nix

• Permethrin 1% (synthetic pyrethroid)

• MOA: Na channel blockade of nerve cells leading to paralysis

• Indications: head lice

• Application

  • Shampoo/rinse/towel dry hair

  • Apply and leave on for 10 min

  • Rinse hair

  • Use nit comb after

• Repeat treatment not required unless lice observed in 7-10 days

• Localized ADRs

• **Remember: RID (DRI) = REPEAT, NIX = NO REPEAT

RID

• Synergized pyrethrins 0.17-0.33% combined with piperonyl butoxide 2-4%

• MOA: block nerve impulse transmission resulting in paralysis, death

  • The piperonyl butoxide prevents breakdown of pyrethrins

• Indications: head and pubic lice

• Application

  • Apply and leave on for 10 min (dry hair)

  • Rinse/shampoo hair

  • Use nit comb after

  • Repeat in 7-10 days

• Localized ADRs

Ivermectin 0.5% Lotion

• MOA: Binds to glutamate-gate chloride channels on nerve and muscle cells

  • Nerve blockade, death

• Indications: head lice

• Application (Similar to RID)

  • Apply on dry hair

  • Leave on for 10 min

  • Rinse hair (no shampoo for 24h)

• Product only applied once, if second application is needed → REFER

• Use of nit comb is not required

• Localized ADRs

Counseling Points

• Counseling points:

  • Pediculicides may not kill 100% of lice eggs

    • Visual inspection of the hair for nits

    • Combing with a nit comb after treatment (Rid and Nix)

  • Avoid physical contact with lice infested patients 

  • Seek medical treatment when

    • Significant irritation or exposure to eyes, mucous membranes

    • Symptoms persist after second application