Diethyl phthalate with methyl salicylate

How it works

Diethyl phthalate provides the parasiticidal/repellent action against ectoparasites, while methyl salicylate is included as a counter-irritant with mild analgesic and antipruritic effect.

Prescribing in practice

• For external use only; avoid contact with the eyes, mucous membranes and broken or inflamed skin, and avoid extensive application in young children.
• It is an older preparation that has largely been superseded by more selective topical insecticides for routine scabies and lice treatment.
• Treat close contacts where appropriate and advise on environmental and laundry measures to prevent reinfestation.

Monitoring

Monitoring is clinical, based on eradication of infestation, relief of itch and any local skin irritation.

Counselling the patient

• Apply only to intact skin and keep it away from the eyes and mouth.
• Itching may persist for a while after successful treatment and does not always mean it has failed.
• Stop and seek advice if marked skin irritation occurs.

Evidence & guidelines

This combination is a traditional topical antiparasitic; current prescribing references favour more selective insecticides as first-line for scabies and lice.