When should I consider seeking medical attention for a poison ivy rash, particularly if the irritation seems to escalate beyond the typical symptoms? At what point do the usual home remedies fail, and the discomfort transforms into a more pressing health concern? Is it when the rash exhibits signs of extensive swelling, or when blistering occurs that may indicate an infection? Can one ascertain the severity of the reaction based on where the rash has developed on the body? For instance, could a poison ivy reaction on sensitive areas, such as the face or genitals, warrant a more immediate response? Furthermore, is there a threshold of duration for the rash—perhaps if it persists beyond a week or shows no signs of improvement—that should compel me to consult a healthcare professional? Additionally, how might underlying conditions or a history of severe allergic reactions influence my decision to seek medical intervention sooner rather than later?