What is the name of the inflammatory condition that causes cracks, crusting and scaling at the corners of the mouth due to vitamin B2 deficiency?

Correct — A. Cheilosis is the cracking, crusting and scaling at the angles of the mouth that follows a deficiency of vitamin B2 (riboflavin) — option (a).

Riboflavin builds the flavin coenzymes FAD and FMN. The fast-dividing cells of the lips and tongue depend on them, so the epithelium at the corners of the mouth splits first when the vitamin runs short.

The full deficiency picture, ariboflavinosis, adds angular stomatitis, a sore magenta-red tongue (glossitis) and a scaly rash around the nose.

Why the others are wrong

• (b)
  Psoriasis — Psoriasis is a chronic immune-mediated skin disease with thick silvery-scaled plaques, typically on elbows, knees and scalp. It is not a vitamin deficiency.
• (c)
  Atopic dermatitis — Atopic dermatitis, or eczema, is an allergic inflammation with itching and dry skin in the flexures, usually beginning in childhood. Riboflavin has nothing to do with it.
• (d)
  Urticaria — Urticaria, or hives, is a sudden wheal-and-flare reaction driven by histamine. It rises and fades within hours and does not crack or scale.

Vitamin items are deficiency-to-disease matches, and the B group is where they get specific, because each B vitamin has its own picture.

B2 (riboflavin) gives cheilosis and angular stomatitis. B1 (thiamine) gives beriberi. B3 (niacin) gives pellagra. B9 or B12 gives megaloblastic anaemia.

The difficulty here is that all three wrong options are real skin diseases. A candidate who reads only cracking and scaling can be pulled to any of them; the deciding phrase is due to vitamin B2 deficiency.

Key facts

• Cheilosis, cracking at the corners of the mouth, is a sign of vitamin B2 (riboflavin) deficiency.
• Riboflavin forms the coenzymes FAD and FMN.
• Thiamine (B1) deficiency causes beriberi and niacin (B3) deficiency causes pellagra.
• Riboflavin is destroyed by light, so milk exposed to sunlight loses it.

Common traps

• Choosing a skin disease from the words cracking and scaling without reading the vitamin named.
• Treating cheilosis as an infection rather than as a nutritional sign.

No directly related past PYQ was found.