Skin Biopsy for Prurigo Nodularis

James Del Rosso:

So you can have a patient presenting with a few nodules and they might be pruritic in some cases, so they have the sensation of wanting to pick at it. And it may be prurigo nodularis, but it could be something else. And that's going to depend on what that tissue in that nodule looks like under the microscope. So there are characteristic features you see with prurigo nodularis. So if you biopsy that lesion, it'll tell you this is characteristic of prurigo nodularis. But if you have some type of infiltrative process that's leading to a tumor or a nodule development that has a different cellular pattern, it's not going to look like prurigo nodularis under the microscope. So there are times where the histopathology and a biopsy may differentiate for you, but usually prurigo nodularis can be diagnosed clinically with good accuracy.