I'm getting itching in my left breast what can be the reason for it and what should I apply or what should I do?

Itchy Breast. Causes of breast itch vary and may include insect bites, allergies, infections, and trauma. When wounds are healing they often start to itch, which is a sign of improvement. One of the itchiest infections you can contract is chickenpox, an extremely common childhood illness. Eczema, contact dermatitis, scabies, and pinworm are other sources of itching. Breast itch can also be a symptom of cancer.