prurire

Prurire, in medical usage often rendered as pruritus, is the sensation that creates an urge to scratch. It can be acute or chronic, lasting days to months, and ranges in severity. In some languages prurire serves as a direct verb meaning to itch, while pruritus is the standard clinical noun. The condition is a symptom rather than a disease, with many possible underlying causes.

Causes include dermatologic conditions such as xerosis (dry skin), atopic dermatitis, eczema, psoriasis, urticaria, and contact dermatitis; systemic diseases including liver or kidney disease, cholestasis, thyroid disorders, iron deficiency anemia; infections such as scabies or fungal infections; pregnancy-related itch; and drug-induced pruritus from opioids, antibiotics, or antihypertensives. Often, itch remains idiopathic after evaluation.

Pathophysiology involves sensory fibers in the skin (unmyelinated C-fibers) and diverse mediators. Histamine mediates some cases, but chronic pruritus frequently involves non-histaminergic pathways and central processing mechanisms. The itch-scratch cycle can damage the skin and perpetuate symptoms.

Diagnosis relies on history and examination, with targeted lab tests (liver and kidney function, thyroid tests, CBC) or skin scrapings when indicated to identify causes. Additional investigations are guided by red flags or persistent symptoms.

Treatment aims at the underlying cause and symptom relief. Skin hydration with emollients, and anti-inflammatory topicals (steroids or calcineurin inhibitors) help many dermatologic etiologies. Antihistamines often offer limited relief for chronic itch; gabapentinoids, certain antidepressants, or specialized therapies may be used for refractory cases. Severe pruritus may require phototherapy or other targeted treatments.