Bruising

Unexplained Bruising: Weighing the Pros and Cons of Possible Causes

Jami Reaves, DO
Greg Wallace, DO
Volume 9 - Issue 6 - June 2010

THE CASE


Figure – This bruise in an infant boy's right popliteal fossa was one of a number of unexplained bruises, which raised suspicion for abuse.A 3-month-old boy was brought by his mother to his busy primary care physician's office for follow-up of bronchiolitis when numerous bruises were noted. The mother said that the infant had a 1-week history of unexplained bruising, petechiae, and irritability. The child was referred to the local emergency department (ED) because of concern for nonaccidental trauma.

On questioning, the mother stated that a bruise over the child's right cheek resulted from a bump to the head that he sustained while being carried over his father's shoulder and sucking on a pacifier. She did not know how he had acquired the other bruises.

The child was the product of a full-term pregnancy. The mother denied use of any drugs or any history of illness during her pregnancy; however, results of maternal testing for group B streptococci were positive. Birth weight was 2.9 kg (15th percentile) and length was 51 cm (50th percentile). The infant had a vitamin K injection in the newborn nursery. In addition, he had a nuchal cord and had to remain in the neonatal ICU for 5 days because of difficulty in breathing. Circumcision was performed during this stay; there was no significant bleeding.

The infant's medical history was significant only for bronchiolitis 3 weeks before this visit; he had recently completed a 10-day course of amoxicillin(Drug information on amoxicillin). He had been formula-fed since birth and was currently taking no medications. Growth and development were within normal limits. Family history was significant for cystic fibrosis (CF) in a maternal great-uncle (although this was revealed only after extensive questioning). There was no other pertinent medical or social history.

Physical examination in the ED revealed a temperature of 36.4°C (97.5°F); heart rate, 131 beats per minute; respiration rate, 36 breaths per minute; length, 54 cm (below the 3rd percentile); head circumference, 39.5 cm (10th percentile); and weight, 5.95 kg (50th percentile). Examination of the head, ears, eyes, nose, and throat revealed petechiae on the hard palate, bilateral otitis media, and anterior cervical chain lymphadenopathy. Lungs were clear to auscultation. Purpuric/ecchymotic lesions were noted in the perioral, buccal, and occipital regions. The patient also had similar bruises in the right popliteal fossa (Figure) and on the left thigh and back. The remainder of the physical findings were normal.

Answer: The bruises were the result of cystic fibrosis presenting as a coagulation disorder.

 

DISCUSSION

Because the history and presentation were concerning for physical abuse, the child abuse team was consulted in the ED.

Studies to include in a workup for suspected child abuse. A skeletal survey and head CT were obtained; neither showed evidence of abuse. Pediatric ophthalmology was consulted: no retinal hemorrhages were identified. Note that a skeletal survey, head CT scan, and pediatric ophthalmology consultation are all justified in any child younger than 24 months who has unexplained injuries.1

Laboratory studies included in a workup for unexplained bruising. Laboratory studies in the ED revealed a white blood cell count of 17,100/μL; hemoglobin level, 8.1 g/dL; hematocrit, 26.3%; reticulocyte count, 1.9% (normal, 0.5% to 1.9%); and platelet count, 541,000/μL. Prothrombin time (PT) was greater than 120 seconds (normal, 10.1 to 13.6 seconds); fibrinogen level was 565 mg/dL (normal, 200 to 400 mg/dL); thrombin time was 12.3 seconds (normal, 14.2 to 21.3 seconds); and partial thromboplastin time (PTT) was greater than 120 seconds (normal, 26.4 to 35.9 seconds). Results of urinalysis were normal. γ-Glutamyltransferase level was 86 U/L (normal, 6 to 19 U/L); alkaline phosphatase level was 511 U/L (normal, 145 to 320 U/L); and total protein level was 5.3 g/dL (normal, 5.4 to 7.0 g/dL). Total iron-binding capacity was 188 μg/dL (normal, 215 to 450 μg/dL). Results of other liver and renal function tests were normal for the child's age. A chest radiograph showed opacity in the upper lobe of the right lung compatible with atelectasis, although pneumonia could not be definitively excluded.

The child was admitted to the hospital for further diagnostic testing and treatment. Hematology was consulted for workup of the elevated PT, PTT, and fibrinogen level. Treatment with tobramycin and cefipime was started for presumed pneumonia until further workup could be completed. On the second day of his hospital stay, after initial screening tests and storage of additional blood, the child was treated with vitamin K.

The Key Points
This infant's case illuminates 2 key points:
•In an effort not to make unfounded allegations and yet protect innocent children, physicians dealing with abuse and neglect should do broad screening tests in an attempt to exclude rare underlying organic diseases. Thus, a coagulation evaluation is warranted in any child with significant, unexplained bruising.
•Although it happens infrequently, cystic fibrosis (CF) can present as a bleeding disorder. Thus, while a rare occurrence, CF can mimic child abuse.3-5

Differential diagnosis of abnormal clotting in an infant. Any malabsorptive disorder that affects vitamin K absorption could have been the cause of this patient's symptoms and laboratory abnormalities. The complete differential diagnosis included celiac disease, α1-antitrypsin deficiency, hepatitis, abetalipoproteinemia, warfarin exposure, and biliary atresia.2 Factors II, VII, IX, and X are vitamin K–dependent, but the liver produces virtually all clotting factors. Here, however, other liver diseases did not need to be considered because of the high fibrinogen level and normal liver function test results. Vitamin K absorption can also be affected by altered bacterial colonization resulting from antibiotic use. Young children are particularly sensitive to vitamin K malabsorption disorders because very little vitamin K is transferred across the placenta and the reserves are thus very small. The most plentiful source of vitamin K in children's diets is commercial formula; breast milk is a very poor source. The absorption of vitamin K is dependent on intact biliary and pancreatic function. A small amount will be synthesized by normal gut flora.

On the basis of the history and laboratory test results, hemorrhagic disease of the neonate and CF figured prominently in this patient's differential diagnosis.

Outcome of this case. Results of sweat chloride testing were positive, with an initial value of 84 mEq/L (normal, less than 60 mEq/L) and a second value of 92 mEq/L on hospital day 2. Serum levels of fat-soluble vitamins were obtained: the vitamin A level was less than 140 μg/dL (normal, 140 to 520 μg/dL), and the vitamin D level was 5 pg/mL (normal, 9 to 46 pg/mL). Results of lung/bronchoscopy cultures were returned on day 3 and were positive for β-lactamase–producing Haemophilus influenzae. Coagulation factors had all normalized within 48 hours, after 2 doses of vitamin K.