I have a red bite on my thigh with a red streak coming out of the top and bottom of it. What could be the cause of it?

R/O CELLULITIS. Cellulitis is a superficial skin infection that can be caused after an abrasion/bite/rupture of a boil . if it is extending up your arm SEEK PROMPT MEDICAL ATTENTION YOU MAY NEED IV ANTIBIOTICS. Seek prompt evaluation for potential need of IV VS oral antibiotics/X-ray /labs. SEEK PROMPT EVALUATION SINCE INFECTION IS PROGRESSING.