Final answer:
Circulating pruritogens are substances in the blood that induce itching. Examples include histamine, cytokines, bile salts, and opioids. Treatment involves addressing the underlying cause and using medications to alleviate itching.
Step-by-step explanation:
Circulating pruritogens refer to substances found in the blood that can induce itching. These substances include histamine, cytokines, bile salts, and opioids. When these pruritogens bind to specific receptors on nerve endings in the skin, they trigger the sensation of itching.
For example, in cholestatic liver diseases, such as primary biliary cholangitis, increased levels of circulating bile salts can cause intense itching. In chronic kidney disease, the accumulation of uremic toxins in the blood can also lead to pruritus.
Treatment for pruritus involves identifying and addressing the underlying cause. Antihistamines, topical corticosteroids, moisturizers, and medications that block specific nerve receptors can be used to alleviate itching.