Pruritus. What to do when the itching won't stop.

Pruritus is a common problem that can result from many conditions. Some, such as fungal or parasitic infection, may be fairly obvious. However, others, such as iron deficiency and psychogenic disorder, are more difficult to diagnose. Evaluation must include a thorough inspection of the skin, history taking for drug intake and chemical exposure, and appropriate laboratory testing. The location on the body and characteristics of the itching may point to a cause. In some cases, attention to exacerbating factors (eg, dry skin, coarse fabrics against the skin, dry environmental conditions) and application of topical preparations may be sufficient. Antihistamines are the foundation of oral treatment, and with the advent of second-generation agents, they can be taken with fewer concerns about their sedative effects. Specific conditions of which pruritus is one feature may require specific treatment. For example, in patients undergoing dialysis, activated charcoal, UV light treatment, or heparin therapy may be useful.