Riboflavin deficiency — DTM&H MCQ

Correct answer: D — Riboflavin (B2)

The correct answer is D, Riboflavin (B2). Ariboflavinosis classically presents with the triad of angular stomatitis, glossitis, and seborrhoeic dermatitis (nasolabial folds, scrotum), accompanied by a normocytic (not macrocytic) anaemia due to pure red cell hypoplasia rather than impaired DNA synthesis. Alcoholics and those on cereal-dominant diets with poor dairy, meat and green vegetable intake (as in rural India) are at particular risk because riboflavin is poorly stored and requires regular dietary replenishment. The combination of mucocutaneous signs with a normocytic (rather than macrocytic) anaemia is the key discriminator that separates this from the B12/folate deficiencies, which cause megaloblastic, macrocytic anaemia. This clinical picture is well described in tropical medicine texts as the classic presentation of hyporiboflavinosis, with the signs including <cite index="1-1">sore throat, hyperaemia, oedema of the pharyngeal and oral mucous membranes, cheilosis, angular stomatitis, glossitis, seborrheic dermatitis, and normochromic normocytic anaemia associated with pure red cell cytoplasia of the bone marrow</cite>. Why the other options are wrong: C. Pyridoxine (B6): B6 deficiency classically causes a sideroblastic (microcytic) anaemia, peripheral neuropathy and seizures in infants, not the seborrhoeic dermatitis and angular stomatitis triad described here. A. Cobalamin (B12): B12 deficiency produces a macrocytic megaloblastic anaemia with neurological features (subacute combined degeneration), inconsistent with the normocytic anaemia in the stem. B. Folate: Folate deficiency also causes macrocytic megaloblastic anaemia, not normocytic anaemia, and lacks the characteristic seborrhoeic dermatitis of ariboflavinosis. E. Vitamin C: Scurvy presents with gum bleeding, perifollicular haemorrhages and poor wound healing, not mucocutaneous stomatitis or dermatitis with normocytic anaemia. Key point: Angular stomatitis, glossitis and seborrhoeic dermatitis with a normocytic (not macrocytic) anaemia points to riboflavin (B2) deficiency, distinguishing it from the macrocytic anaemias of B12/folate deficiency.

Reference: Manson's Tropical Diseases (23rd edition), chapter on Nutritional Deficiency Disorders, section on riboflavin deficiency (ariboflavinosis); consistent with WHO nutrient deficiency descriptions