The physician’s most important diagnostic tools are a thorough and systematic history and physical exam. Laboratory testing for systemic disease may be necessary. Common questions include the following:
- What are the extent, severity, and quality of the itch?
- When does the pruritus occur, and what is its duration?
- Are there provocative factors, such as change in temperature or climate?
- Does the patient have a history of previous skin disorders or allergies?
- What are the patient’s current medications?
- Has the patient taken any new oral medications or ingested any new foods?
- How often does the patient bathe?
- What products does the patient use on his/her skin?
- Has the patient used any new skin products?
- Is there a history of systemic illness?
- Is health maintenance up to date?
- Is there a history of psychiatric illness?
- What is the home environment?
- Are there pets at home?
- Does any other family member experience itching?
- Has there been any recent travel?
- Is there any emotional stress?
In examining the skin, the physician should focus on whether it is normal or abnormal. Care should be made to differentiate between primary and secondary skin lesions. The primary skin lesion can identify the causal disease, whereas secondary skin lesions are usually reactive from the pruritus itself. Pruritus can occur in the setting of normal skin.
