In the diagnosis of vasculitis, while ANCA positivity is often associated with certain types of vasculitis, it's crucial to remember that it can also occur in other conditions such as infections, inflammatory bowel disease, and even drug-induced syndromes. This can lead to diagnostic confusion and potentially misdirected treatment plans. Therefore, clinicians must consider the entire clinical context and not rely solely on ANCA results to make a definitive diagnosis of vasculitis since even ANCA positivity may be sometimes a red herring! 

ANCA may be found in a variety of conditions other than ANCA-associated  vasculitis, including inflammatory bowel diseases, other autoimmune diseases, and infections where their clinical significance is unclear. Which other conditions do you know?