A bumpy head can be caused by an infant’s fontanel not yet closed, or by other factors such as seborrheic dermatitis or urticaria. Unevenness of the top of the head is more common in infants and young children, who are in the developmental stage of their bodies. Therefore, infants before the age of one and a half years old tend to show unevenness of the top of the head because the fontanel has not yet completely healed. If this symptom does not improve with age, consider the presence of craniosynostosis. Urticaria often causes localized skin edema, and patients may present with itchy, uneven, erythematous bumps of various sizes on the surface of the skin. Seborrheic dermatitis is often associated with heredity, exuberant sebum secretion, local microbial colonization and other factors, patients with exuberant sebum secretion of parts such as scalp, chest and back can appear erythema, papules, greasy scabs, which can be manifested as a bumpy phenomenon on the top of the head. When patients experience discomfort, they should go to the hospital immediately.