pruritus

[Latin prūrītus, from past participle of prūrīre, to itch.]

Itching.

Itching; common in many types of skin disorders, especially allergic inflammation and parasitic infestations. Its presence in animals is inferred because of the presence of scratching, which would be a more accurate description. Pruritus is epidermal in origin and does not occur in deep ulcerations, although they may be painful. It is most intense at mucocutaneous junctions. See also paresthesia, hyperesthesia.

• p. ani — intense chronic itching in the anal region. May be caused by perianal dermatitis, intestinal parasitism and anal sac disease in dogs and cats.
• cholinergic p. — caused by stimulation of afferent cholinergic fibers at the neuroglandular junction of the sweat gland with release of acetylcholine and sweat. There is mast cell degranulation. Called also heat reflex urticaria.
• essential p. — that occurring without known cause.
• symptomatic p. — that which occurs secondarily to another condition.