Itchy anus, itchy stomach, itchy head, red lines on stomach. worm? candida?

Hard to say: Candida and pinworms both can cause itchy anus(Pruitis Ani), but there are a number of other infections and dermatologic conditions that may be responsible. There is no way to tell from such limited information if all your symptoms are related to one disease(probably not.) You need to see a physician for an examination or consider an online consultation at Health Tap