I agree with you guys, rickets is the first differential that comes to mind...but if u look at the overall nutrition, skin texture etc. ( this child seems ok ), since rickets due to nutritional deficiency will coexist with other nutritional deficiencies and the child will have a more sicker look ( although only the lower half of the image is visible and so it is hard to tell ). So, i will keep Blount's disease as my second differential. Relevance in today’s context ”“ These days parents are very aggressive and what their kids to take their first baby steps by age 5 months, walk and fetch the tv remote by 7 months and burn the dance floor on the first birthday. I know of a couple that had infant walkers ready even before their child was born (not kidding”¦they had borrowed it from their relatives b4 somebody else borrowed it). Early walking with or without infant walkers sets the stage for bow legs which is further compounded if the child is on the wrong side of the weight curve( and extreme form of which is called Blount’s disease / tibia vara ”“ for which early walking and childhood obesity is thought to be one of the causes). So my third differential is Tibia vara due to early introduction of child walker. Let the child learn to walk naturally...the muscles will develop when they have to do the entire work against gravity and those early lessons in balancing and proprioception ( mitigated by using the child walker ) could well pave the way for the next Michael Jackson. wink)
Related Self Assessment Question ( Asked on both Step 1 and 2 ) A very upset mother brings her 8-month-old child to the emergency room because he will not move his leg. She reports that when she was carrying him to the car about half an hour ago, she slipped on some ice and fell on top of him. The mother, an 18-year-old African American woman, has been exclusively breast-feeding her child. She has only recently started him on cereals, and has not supplemented his diet with vitamins. A radiograph of the child's leg is shown below. Which of the following laboratory findings would be expected? (Courtesy of Susan John, MD.) A. Hypocalcemia B. Hypophosphaturia C. Reduced serum alkaline phosphatase D. Hypocalciuria E. Hyperphosphatemia EXPLANATION: The x-ray demonstrates a fracture of the femur, and also a significant decreased bone mineralization. The child in the question (exclusively breast-fed, no vitamin D supplementation, northern climate with limited sun exposure, African American mother) is at risk for simple (nutritional) rickets. Nutritional rickets is caused by a dietary deficiency of vitamin D and lack of exposure to sunlight. Intestinal absorption of calcium and phosphorus is diminished in vitamin D deficiency. Transient hypocalcemia stimulates the secretion of parathyroid hormone and the mobilization of calcium and phosphorus from bone; enhanced parathyroid hormone activity leads to phosphaturia and diminished excretion of calcium. In children with nutritional rickets, the concentration of serum calcium usually is normal and the phosphate level is low. Increased serum alkaline phosphatase is a common finding. The excretion of calcium in the urine is increased only after therapy with vitamin D has been instituted. The answer is D.
