My mother (83) has a lump on her wrist just below her thumb on the palm side (possible ganglion cyst?). It came up yesterday and caused pain and some difficulty in moving. Mobility returned and discomfort lessened today but tonight we noticed a red streak going from the lump up her arm. It is slightly above her elbow at this point. What could cause the redness? She hasn’t injured herself and doesn’t have any sores. Do we need to take her to the ER?