The first step in the evaluation of chronic pruritus is to determine if the itch can be attributed to a dermatologic disease, or whether an underlying noncutaneous cause is present. A detailed review of systems and a thorough drug history should be performed. Pruritus is sometimes the first manifestation of systemic diseases such as Hodgkin's disease or primary biliary cirrhosis, antedating other symptoms by months or longer. The skin should be examined carefully to assess for primary skin lesions.
It should be recognized that excoriations, nonspecific dermatitis, prurigo nodularis, and LSC (lichen simplex chronicus) are secondary lesions, for which an underlying cause should be sought. Excessively dry skin (xerosis) usually presents with minimally detectable changes, but erythematous and scaly inflammatory patches may develop. In addition to the history and physical examination,…