Hi,
Yes, it is advisable to see a doctor about an itchy mole on your neck, particularly since it is red and fairly large. While it may not show signs of asymmetry or blurry edges, changes in color, shape, size, and texture of a mole could indicate possible 
skin cancer or other skin conditions that require prompt medical attention. Additionally, itchiness in a mole is not a normal symptom and could be a sign of an underlying issue.
Your doctor may recommend a 
biopsy of the mole to determine whether it is benign or malignant and whether it needs further treatment. They may also examine other 
moles on your body and recommend regular skin checks to monitor for any changes or signs of skin cancer.
If you require a personalized response, kindly use the 
Ask A Doctor service and post a follow-up. Take care. Hope I have answered your question.
Regards,
Dr. Priyanka, General & Family Physician