prurigo nodularis
Prurigonodularis (PN) is a skin disease in which hard crusty lumps are formed on the skin that itches intensely. Repetitive rubbing, scratching, and touching results in more lesions in the skin. The itching is so intense that people scratch themselves to the point of bleeding or pain. The lumps formed in the skin are hard, and have about a half inch across, with a dry and rough top that is often scratched open. They tend to be located in the areas most easily reached and are worse on the outer sides: arms, shoulders and legs. The trunk, face and even palms can also be affected. The exact cause is unknown but some factors triggering PN include liver and kidneys problems, nervous and mental conditions and other skin diseases. Prurigo nodulares, in some cases, can be seen in other diseases such as lymphoma, chronic autoimmune cholestatic hepatitis, HIV infection, severe anemia,or a chronic kidney disease-related itching known as uremic pruritus. Treatment is very difficult, and may include corticoids, antihistaminic and other medication such as thalidomide and similar (Lenalidomide). In some cases, cryotherapy, photochemotherapy and habit reversal therapy for the itch-scratch cycle has improved the symptoms. PN can last for many years, and the itching is so intense that may affect all the everyday activities.