Vitamin K Deficiency Bleeding (VKDB): This condition is a common cause of purple rash in infants, particularly in those who did not receive vitamin K at birth. The rash is often accompanied by bleeding or bruising.

Erythema Multiforme: A skin condition characterized by target-like lesions, which can appear purple. It's often triggered by infections or medications.
Henoch-Schönlein Purpura (HSP): A form of vasculitis that can cause a purple rash, typically on the legs and buttocks. It's often accompanied by joint pain and abdominal symptoms.
Allergic Reactions: Allergic reactions to medications, foods, or environmental factors can cause a purple rash in infants.

Meningococcemia: A life-threatening infection caused by Neisseria meningitidis, which can cause a purple rash (purpura). It's essential to recognize and treat promptly to prevent severe complications.
Disseminated Intravascular Coagulation (DIC): A condition characterized by widespread clotting and bleeding, which can cause a purple rash. It's often associated with severe infections, trauma, or other critical conditions.
Child Abuse: Non-accidental trauma can cause a purple rash or bruising in infants. It's crucial to consider this possibility and investigate further if suspected.

Kawasaki Disease: A rare condition that causes inflammation in the blood vessels, which can lead to a purple rash. It's often accompanied by fever, conjunctivitis, and lymphadenopathy.
Congenital Disorders: Certain genetic disorders, such as congenital cytomegalovirus infection or congenital syphilis, can cause a purple rash in infants.
Leukemia: Although rare, leukemia can cause a purple rash or bruising in infants due to bone marrow failure and bleeding tendencies.