Parasites of the skin and hair.

Because scratching is nature's treatment for ectoparasites, they should be considered in the differential diagnosis of any pruritic rash. Usually, the diagnosis is not difficult to make if the clinician suspects an ectoparasitic cause and is familiar with the symptoms and signs of these disorders. The diagnosis is confirmed using a few instruments and basic office supplies. The clinician must treat not only the individual patient but must also consider the source of the infection because others may require treatment. Family and community education about removal of the parasites from the patient's environment is one of the clinician's responsibilities.