A recently adopted 9-year-old weighing 20 kg presents with a geographic and swollen tongue. What is the most likely explanation?

Correct answer: B. Malnutrition with associated nutritional deficiencies

• A. Toothpaste allergy or a sodium lauryl sulfate reaction can cause mucosal irritation and desquamation, but it would not account for the growth deficit that anchors this case.
• B. CORRECT. The critical clue is the WEIGHT: 20 kg at 9 years is far below the expected range (roughly 28–32 kg) and indicates significant undernutrition. MALNUTRITION — with deficiencies of B-complex vitamins (B2, B3, B6, B12), folate, iron, and zinc — produces atrophic and inflamed glossitis, a swollen tongue, and migratory/geographic patterning. Recent adoption raises the possibility of prior neglect or deprivation, and medical referral for nutritional assessment is indicated.
• C. Primary herpetic gingivostomatitis presents acutely with fever, painful vesicles and ulcers, and markedly inflamed gingiva — a very different picture.
• D. Geographic tongue alone can be a benign variant, but combined with a swollen tongue and marked underweight it should not be dismissed.