This week, we are sharing another USMLE® Step 1-style practice question to test your knowledge of medical topics. Today’s case focuses on a 6-month-old boy who was taken to a hospital following an accident. Physical examination reveals several bruises over the trunk and extremities at different stages of healing, which the parent attributes to falls that occurred while he was learning to walk. Can you figure out which of the following is the most likely cause of this patient’s symptoms?
A 6-month-old boy is brought into the emergency department by his parent following a motor vehicle accident. The parent states they were stopped at an intersection when another car hit hers in the rear. The patient was restrained in a car seat during the accident. At arrival, the patient’s temperature is 37.6°C (99.7°F), blood pressure is 95/47 mmHg, and pulse is 109/min. Weight is at the 10th percentile and height is at the 60th percentile. The patient is inconsolable by his parent. Physical examination reveals several bruises over the trunk and extremities at different stages of healing, which the parent attributes to falls that occurred while he was learning to walk. There is significant tenderness over the right leg and any manipulation of the extremity causes pain. Imaging reveals a spiral fracture of the femur. Which of the following is the most likely cause of this patient’s symptoms?A. Osteogenesis imperfecta
B. Vitamin C deficiency
C. Rickets
D. Accidental trauma
E. Child abuse
Scroll down to find the answer!
The correct answer to today’s USMLE® Step 1 Question is…
E. Child abuse
Before we get to the Main Explanation, let’s look at the incorrect answer explanations. Skip to the bottom if you want to see the correct answer right away!
Incorrect answer explanations
The incorrect answers to today’s USMLE® Step 1 Question are…
A. Osteogenesis imperfecta
Incorrect: Children with osteogenesis imperfecta have a congenital defect in the synthesis of type I collagen. These patients are predisposed to various bone fractures, even in the setting of minimal trauma. Other physical examination findings include short stature and blue sclerae, neither of which are present in this patient.
B. Vitamin C deficiency
Incorrect: Vitamin C is necessary for proper collagen synthesis and formation. Vitamin C deficiency can result in fragile vasculature and easy bruising. Although this patient has several bruises over the body, the spiral femoral fracture and inconsistent history provided by the parent suggest a different diagnosis.
C. Rickets
Incorrect: Rickets is usually caused by vitamin D deficiency. In children, the condition can present with bone pain, deformation, and fractures. Although this patient has a femoral fracture, the presence of bruises in various stages of healing and the parent’s inconsistent story (children do typically begin standing or walking until 9-12 months of age) are concerning for child abuse.
D. Accidental trauma
Incorrect: Trauma, such as a car accident, can lead to bruising and fractures. However, the bruising would typically be in a specific pattern, such as along the path of a seatbelt. In contrast, this child’s bruising is widespread and in various stages of healing. Moreover, the parent’s inconsistent history should raise suspicion for child abuse. In general, children do not typically begin standing or walking until 9-12 months of age.
Main Explanation
This 6-month-old child, who is not yet capable of standing or walking, presents with several bruises in different stages of healing as well as a spiral femoral fracture. These findings are suggestive of child abuse, which demands immediate attention and action.
Children in unstable family situations (e.g., single-parent homes, domestic violence, parental substance use disorders) are at increased risk of enduring child abuse. As soon as child abuse is suspected, a skeletal survey should be performed to evaluate for additional occult fractures. Findings suspicious for child abuse include bruises or fractures at various stages of healing, femoral fractures in non-ambulatory infants, and posterior rib fractures. Additional diagnostic evaluation should include an ophthalmic examination to evaluate for retinal hemorrhages and a head CT to assess for intracranial bleeding.
If a healthcare provider suspects child abuse or neglect, local child protective services should be notified immediately. Management of patients with child abuse entails stabilization, identification, and treatment of all injuries, including a low threshold for hospitalization.
Major Takeaway
Child abuse should be promptly identified in children presenting with injuries incongruent with the patient’s developmental age, repeated hospitalization for unexplained injuries, or history of sexually transmitted infections. If child abuse is suspected, child protective services should be immediately notified.
References
Kodner, C., Wetherton, A. (2013) Diagnosis and management of physical abuse in children. American Family Physician. 88(10), 669-675. PMID: 24364482.
Swerdlin, A., Berkowitz, C., Craft, N. (2007) Cutaneous signs of child abuse. Journal of the American Academy of Dermatology. 57(3), 371-392. Doi: 10.1016/j.jaad.2007.06.001.
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The United States Medical Licensing Examination (USMLE®) is a joint program of the Federation of State Medical Boards (FSMB®) and National Board of Medical Examiners (NBME®). Osmosis is not affiliated with NBME nor FSMB.
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