Is one such course of treatment sufficient to bring about a cure?

Yes, in ordinary cases, if the applications have been carefully and thoroughly made; exceptionally, however, some parasites and ova escape destruction, and consequently itching will again begin to show itself at the end of a week or ten days, and a repetition of the treatment become necessary.

Does the secondary dermatitis which is always present in severe cases require treatment?

Only when it is unusually persistent or severe; in such cases the various soothing applications, lotions or ointments employed in acute eczema are to be prescribed.

Is a dermatitis due to too active and prolonged treatment ever mistaken for persistence of the scabies?

Yes.

Pediculosis.

(Synonyms: Phtheiriasis; Lousiness.)

Define pediculosis.

Pediculosis is a term applied to that condition of local or general cutaneous irritation due to the presence of the animal parasite, the pediculus, or louse.