It sounds like your scalp might be reacting to the rapid hair growth, which can sometimes cause itchiness due to increased oil production or sensitivity. Dandruff could be a sign of dryness, buildup, or even a mild fungal imbalance, which might explain the itching too. An anti-itch shampoo could definitely help, especially if it has ingredients like tea tree oil, salicylic acid, or zinc pyrithione, which are great for calming irritation and addressing dandruff.
You might also want to try moisturizing your scalp with a light oil (like argan or jojoba oil) to balance dryness. If the problem persists or worsens, it could be worth checking with a dermatologist to rule out any underlying scalp conditions. But hey, congrats on the extreme growth—that’s a nice silver lining!