A 12-month-old presents with poor muscle tone, irritability, concave nailbeds, and edema. Which disorder is most consistent with these findings?

• A. Hemophilia
• B. Lymphoma
• C. Iron deficiency anemia
• D. Lead poisoning

Answer: (C)

Iron deficiency anemia in young children often presents with spoon-shaped nails (koilonychia), irritability, and reduced muscle tone from decreased oxygen delivery to tissues. The concave nails are a classic clue that points toward iron deficiency rather than other disorders. In a 12-month-old, inadequate iron intake during a period of rapid growth is a common cause, and the resulting microcytic, hypochromic anemia leads to fatigue and irritability, with less robust muscle tone as the body tries to conserve energy. The other conditions would show different hallmark features—bleeding problems with visible bleeding or easy bruising for a bleeding disorder, swollen lymph nodes or systemic symptoms for lymphoma, or toxin-related signs and a different lab pattern for lead poisoning—whereas the nail change together with these anemic symptoms best fits iron deficiency.