Melissa Schmalz, DO Western Medical Associates Failure to thrive Grand Junction, Colo Kate Boos, MD A 13-month-old girl is anemic and not gaining enough Cozad Community Medical Clinic weight. How would you proceed with her care? Cozad, Neb Grant Schmalz, PharmD Advanced Pharmacy Services Grand Junction, Colo 13-month-old girl arrives at your clin- supplementation, vaccination, and care ic, referred by the staff at the Women, of minor illnesses. Mark K. Huntington, MD, PhD, FAAFP A Infants, and Children (WIC) nutri- • She hasn’t been in for a well-child visit Center for Family Medicine tional center where her parents—recent immi- since then, but she has been seen for an Sioux Falls, SD grants from Africa—go for food supplements. upper respiratory infection and a bout of [email protected] The baby is bundled up in layers of clothing, gastroenteritis. Her parents have not been The authors reported no even though it’s a relatively mild winter day. worried about her health. potential conflict of interest relevant to this article. The father carries her into the examining room • The parents tell you the baby doesn’t and undresses her. The child is tiny and dark- sleep soundly, scratches her skin in her ® skinned, with curly hair painstakingly divided Dowdensleep, and Health cries a lot. Media into little bunches. The parents seem caring, loving, and not particularlyCopyright worried. They tell Family and social history you the nurse at the WIC center thoughtFor their personal • The parents use speak only very little English. baby was not gaining enough weight and ad- • The patient is an only child, and no ex- vised them to bring the baby to you. The re- tended family live in the area. ferral note from WIC says hemoglobin levels • Her mother works nights and her father found on routine blood test were low. You list works days, with the parent who is not the presenting complaint as anemia. working caring for her at home. • Her parents tell you she takes small sips of juice or water, and an occasional bite of What are some of the etiologies noodles. She won’t drink milk at all and for anemia in a child this age? refuses any other foods they offer. What strategies would you use to narrow down the cause? Physical examination • The child is in no acute distress. She is afebrile, and her vital signs are appropri- ate for her age. • Height is 27½ inches, weight 15 lb, 15 oz, placing her at less than the 5th percen- Additional medical history tile for height and weight for her age—a • The birth history is unremarkable, with regression from the 50th percentile she neither antepartum nor postpartum com- showed at earlier visits. plications. • Head and neck exam reveals mild frontal • At her 6-month well-child checkup, nei- bossing and prominent sternoclavicular ther the child’s physician nor her parents joints. There is no adenopathy or thyro- expressed any concerns about her devel- megaly. opment. Her parents received the routine • Heart and lung exam are normal. anticipatory guidance at that visit, in- • Abdomen is soft, nontender, nondistend- cluding advice on breastfeeding, vitamin ed, with bowel sounds present. CONTINUED ON PAGE 540 JFPONLINE.COM VOL 58, NO 10 | OCTOBER 2009 | THE JOURNAL OF FAMILY PRACTICE 539 For mass reproduction, content licensing and permissions contact Dowden Health Media. Figure 1 Laboratory results The patient, not weight-bearing • Hemoglobin, 9.9 mg/dL (normal: 10.4-12.4 mg/dL) • Mean corpuscular volume (MCV), 74 fL (normal: 70-86 fL) • Alkaline phosphatase, 3417 U/L (normal: 115-460 U/L) • Vitamin D (calcidiol), <7 nmol/L (normal: 60-108 nmol/L) • Calcium, 9.1 mg/dL (normal: 8.8-10.8 mg/dL) • Comprehensive metabolic panel, liver transaminases, and thyroid-stimulating hormone levels are all normal • Parathyroid hormone level, 101 pg/mL (normal: 10-55 pg/mL). The 13-month-old patient has slight bowing of the lower extremities and puffiness around the wrists and Radiologic findings ankles. She needs support to stand. • X-ray shows slight saber deformity of the When you see femurs and broadening of the epiphyses failure to thrive Figure 2 of the forearm (FIGURE 2). in a dark-skinned Forearm x-ray baby, consider rickets. Can this be rickets? Here is a child with a history of poor growth and peculiar eating habits. Her legs are bowed and her wrists seem swollen. She does not stand or walk, and refuses to bear weight on her legs. She is anemic, and the lab tests you’ve ordered show abnormal vitamin D, alkaline phosphatase, and parathyroid hormone lev- els. All of this suggests a diagnosis of rickets. Causes of rickets The patient’s x-ray shows a widening of the epiphyses Rickets is the result of abnormal mineraliza- (black arrow) and pseudofracture (white arrow). tion of bone and cartilage in growing children. The analogous condition in adults whose epiphyseal plates have closed is osteomala- • There is slight bowing of the lower ex- cia. Clinical rickets typically presents with the tremities and puffiness around the wrists constellation of signs and symptoms listed in and ankles. When you ask her father to the box on page 543 and depicted in FIGURES have her stand on the examining table, 1, 2, and 3. you see that she needs support to do so s (FIGURE 1). Not enough vitamin D The most common cause of rickets is a defi- ciency of vitamin D, a substance physiologi- What is your clinical diagnosis, cally necessary to produce concentrations of Y OF THE AUTHOR s and what tests will you order? calcium and phosphate adequate for proper bone mineralization. Vitamin D is produced in COURTE s the skin in the presence of sunlight and can also MAGE I be ingested in supplements and certain foods. 540 THE JOURNAL OF FAMILY PRACTICE | OCTOBER 2009 | VOL 58, NO 10 GRAND ROUNDs: FAILURE TO THRIvE Vitamin D deficiency may result from re- Figure 3 duced sunlight exposure, inadequate dietary Rachitic rosary intake, malabsorption, or a combination of these factors.1 Rickets may also be caused by medications that alter absorption or secretion of phosphate and calcium, including antacids, anticonvulsants, corticosteroids, and loop di- uretics. Various disease states, such as Crohn’s disease, pancreatic disease, biliary disease, gastrointestinal loops and fistulae, cirrhosis, chronic renal disease, and mesenchymal tu- mors, may also alter absorption and metabo- lism of these ions. How much sunshine does a baby need? It doesn’t take a great deal of sunlight exposure to provide adequate supplies of vitamin D. An infant wearing only a diaper will get enough vitamin D from half an hour per week of sun exposure. A fully clothed infant needs Breastfed 3 hours. But children with dark skin, like The patient had a developing rosary, most pronounced infants need at the sternoclavicular joint (white arrow) and early this African baby, need more time in the saber deformity of the shin (black arrows). Frontal supplementation. sun. And if parents follow current anticipa- bossing and swollen wrists and ankles may also be tory guidance about protecting children from seen in patients with rickets. overexposure to the sun and slather on the sunscreen, vitamin D synthesis decreases by more than 95%.2 to measure than the concentration of calcitri- ol, the final step. Mild vitamin D deficiency is Vitamin D in the diet defined as serum calcidiol concentration of Consuming adequate quantities of vitamin D 25 to 50 nmol/L. A serum calcidiol concentra- is difficult, unless the diet includes fortified tion of 12.5 to 25 nmol/L indicates a moder- foods or vitamin supplements. Current rec- ate vitamin D deficiency, and at those levels ommendations for daily intake are 400 IU per the incidence of hypocalcemia and rickets in- day for all infants, children, and adolescents.3 creases. Serum calcidiol concentration of less But the average daily intake by adults in North than 12.5 nmol/L, as in the case of the patient America from sources such as fish, eggs, and presented here, indicates a severe deficiency.4 butter or margarine is only 50 to 100 IU.3 Infants born to vitamin-D replete women Not enough calcium have an 8- to 12-week store of vitamin D at In addition to calcium malabsorption due to birth, but breastfeeding does not ensure the inadequate vitamin D levels, hypocalcemia baby is getting adequate amounts of vitamin may result from inadequate intake of calcium D, even if the mother’s vitamin D status is ad- or from vitamin D-dependent metabolic dis- equate. Human milk from vitamin D-replete orders, of which there are 2 types. women has a vitamin D concentration of only ❚ Type I, sometimes known as pseudo- 25 IU per liter, far below the recommended vitamin D-deficiency rickets, is due to defec- 3 daily intake of 400 IU. tive production of 25(OH)D3-1-α-hydroxylase, an enzyme necessary for the conversion of How deficient is this baby? calcidiol to calcitriol in the kidneys. Vitamin D deficiency may be categorized as ❚ Type II, also called hereditary rickets, is mild, moderate, or severe. Calcidiol is the rare. It is caused by mutations in vitamin D re- next-to-last step in the metabolism of vitamin ceptors and the inability of the ligand to bind D and is used as a marker because it is easier or stimulate the proper physiologic response. CONTINUED ON PAGE 542 JFPONLINE.COM VOL 58, NO 10 | OCTOBER 2009 | THE JOURNAL OF FAMILY PRACTICE 541 In this condition, laboratory tests may show When follow-up and multiple dosing high levels of calcitriol.