Brief Answer:
A minor external injury likely.

Detailed Answer:
Hello,
Thanks for posting your query.
Head injuries fall into two categories external (usually scalp) injuries and internal head injuries, which may involve the skull or the brain.
Fortunately, most childhood falls or blows to the head result in injury to the scalp only, which is usually more frightening than threatening. The scalp is rich with blood vessels, so even a minor cut there can bleed profusely. There may be a "goose egg" or swelling after a head blow as the result of the scalp's veins leaking fluid or blood into (and under) the scalp. It may take days or even a week to disappear.
If your child has not lost consciousness, and is alert and behaving normally after the fall or blow apply an ice pack to the injured area for 20 minutes every 3 to 4 hours (as rightly done). If you use ice, always wrap it in a washcloth or sock; ice applied directly to bare skin can cause cold injury to the skin.
Observe your child carefully for the next 24 hours. If color and breathing are normal, and you observe or sense no other abnormalities, let your child be normal.
If your child can't be awakened or shows any signs of internal injury (see below), visit the doctor if he complaints of head and neck pain, vomits repeatedly, difficult to awaken, isn't walking normally.
Some internal head injuries complications of a fractured skull, torn blood vessels, or damage to the brain itself can be serious and possibly life threatening like unconsciousness for more than a few minutes, bleeding or clear fluid from the nose, ear or mouth, disturbance of speech or vision, neck pain or stiffness, seizure, then would advice to visit your clinician immediately.
I hope this answers your query.
In case you have additional questions or doubts, you can forward them to me, and I shall be glad to help you out.
Wishing you good health.
Regards.
Dr. Praveen Tayal.
For future query, you can directly approach me through my profile URL http://bit.ly/Dr-Praveen-Tayal

---