The main reasons for infants scratching their heads include scalp allergy, ringworm, and ear canal infections. 1. Scalp allergy: if infant scalp allergy leads to eczema, urticaria, contact dermatitis and other allergic diseases on the scalp, in the process of the body’s immune response, the immune cells will release histamine, which can stimulate the infant’s scalp to produce itchy sensation, so the infant is always scratching his head. 2. Tinea capitis: when the infant’s scalp is infected by fungi to form tinea capitis, under the stimulation of fungi and inflammatory factors, the scalp will have intense itching, swelling and heat and other discomforts, which can lead to infants scratching their heads. 3. Ear infections: Whether the itch is caused by an infection of the external ear canal or an infection of the inner ear canal, infants are unable to accurately scratch the itchy location and can only scratch the head where the ear is located. If an infant is scratching his or her head, it is important to take the infant to the hospital in a timely manner to have the cause investigated by a professional doctor for targeted treatment.