There are a number of reasons that a toddler experiences hair loss and in most cases, the condition is not serious.
A toddler may get bald patches on their head from sleeping in a certain position. Many infants will have a bald patch at the back of the head from rubbing against the sheets in the crib. This is normal and is to be expected in most children.
There are however, instances when hair loss should be concerning.
If the bald spots have red, flaky or scaly skin, or if it looks like the hair is broken off at the skin, it could be an infection called tinea capptis, (also known as ringworm). This is a very common cause of hair loss in toddlers.
Hair loss can also be caused by tying ponytails too tight or wearing certain hair accessories. This is called traction alopecia.
If there are irregular bald patches, your child could be pulling their hair out, or twirling their hair. This is known as trachotillomania.
When there are bald patches that are smooth and round, your child could have alopecia areata, which is an immune system disease that attacks hair follicles.
Many times, when a toddler is taking certain medication, they will experience hair loss.
There are also medical conditions that will make a child lose hair. Hypothyroidism and Hypopituitarism can result in full hair loss, although this is rare.