Differential Diagnosis for 7-month-old with Unexplained Bruising and Swelling
- The following differential diagnosis is organized into categories to guide further investigation and management.
Single Most Likely Diagnosis
- Child Abuse: Given the presence of unexplained bruising and swelling in a non-ambulatory infant, child abuse is a significant concern and must be considered as the single most likely diagnosis. The absence of a trauma history and the pattern of injuries (e.g., bilateral arm bruising, right knee bruising, and left wrist swelling) raise suspicions of non-accidental injury.
Other Likely Diagnoses
- Idiologic Thrombocytopenic Purpura (ITP): This condition, characterized by low platelet count due to immune-mediated destruction, can present with bruising and could be a consideration, although the swelling is less typical.
- Henoch-Schönlein Purpura (HSP): Although more common in older children, HSP can cause bruising, swelling, and joint pain. However, it typically presents with a characteristic rash and abdominal symptoms.
- Infection: Certain infections, such as osteomyelitis or septic arthritis, could cause localized swelling and might be associated with bruising if there is significant inflammation or bleeding into the joint.
Do Not Miss Diagnoses
- Hemophilia or Other Bleeding Disorders: These conditions can present with unexplained bruising and swelling, especially after minor trauma or even spontaneously. Although less common, missing a bleeding disorder could lead to significant morbidity or mortality if not recognized and managed appropriately.
- Cancer (e.g., Leukemia): Certain types of cancer, such as leukemia, can cause bruising and swelling due to bone marrow infiltration and subsequent thrombocytopenia or other cytopenias. Although rare, the diagnosis of cancer is critical and potentially life-threatening if missed.
- Scurvy (Vitamin C Deficiency): Scurvy can cause bruising, swelling, and joint pain due to poor collagen synthesis. It's a rare condition in infants but could be seen in cases of nutritional deficiency.
Rare Diagnoses
- Ehlers-Danlos Syndrome: A group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and other organs and tissues. Defects in connective tissues cause the signs and symptoms of these conditions, which can include easy bruising.
- Congenital Disorders of Glycosylation: These are a group of rare genetic disorders that can affect various bodily systems and may present with bruising among other symptoms due to coagulation abnormalities.
- Other Rare Bleeding Disorders: Such as factor deficiencies (other than those seen in hemophilia) or disorders of platelet function, which can present with bruising and swelling.