Classification of Itch

Eighteen experts from eight countries proposed a classification of itch based on clinical signs:

• Pruritus on diseased (inflamed) skin (e.g., atopic dermatitis)

• Pruritus on nondiseased (noninflamed) skin (e.g., pruritus of renal failure)

• Pruritus presenting with severe, chronic, secondary scratch lesions (e.g., prurigo nodularis)

They then categorized itch based on the underlying disease:

• Dermatologic

• Systemic

• Neurologic

• Psychiatric/psychosomatic

• Mixed disease

• Other or undetermined origin

The discussion provides diagnostic examples of each category. The authors stress that the various forms of itch are not identical and that treatment depends on classification and category.