There has been a recent notable increase in scabies and pediculosis pubis and pediculosis capitis. Once the diagnosis is established (preferably by demonstrating the mite or louse), therapy includes consideration of a risk to benefit ratio, explanation of the nature of the infestation to the patient, application of appropriate therapeutic techniques, and follow-up procedures. Resistance of the Sarcoptes mite to modern scabicides has been suggested but not proved. Resistance of the head louse and body louse to modern pediculicides has been reported in other countries but not in the United States.