Causes of a red streak running up the arm include infection from a skin injury, animal or insect bite, or a piercing or tattoo, according to WebMD. Other signs of infection are pain, redness, warmth and swelling around the area of the injury, pus and fever.
The bacteria that cause infection can come from an object that pierces the skin, from the environment or from the patient's own skin, states WebMD. Cleaning and protecting the wound reduce the chances of infection, but those who have pre-existing conditions such as diabetes, weakened immune systems or peripheral artery disease are more at risk.
Scabies is an itchy rash caused by a mite that is too small to be visible with the naked eye, explains the American Academy of Dermatology. The mite burrows under the skin and causes an inflammation in the form of a rash. Sometimes, the rash forms tiny red bumps that travel in a line. A person who has suffered a previous attack of scabies may start to itch after one to four days, while a person who has never had an attack may take weeks to start itching.
Poison ivy contains an oil that causes an allergic reaction that often leads to red streaks, according to the American Academy of Dermatology.