Question

Which of the following is a skin disease?

• A. Anaemia
• B. Pellagra
• C. Osteomalacia
• D. Rickets

Hint:

Pellagra is caused by niacin (Vitamin B3) deficiency and shows up as skin dermatitis.

Answer 1

The Correct Option is B

Step 1: Understand what the question is asking.
The question asks which of the four listed conditions is a disease of the skin. Three of these four options are actually bone or blood disorders, so we need to know what each condition really affects before we pick the odd one out.

Step 2: Recall what pellagra is.
Pellagra is a deficiency disease caused by a lack of niacin, also called Vitamin B3, in the diet. It is remembered by the "three Ds": dermatitis (skin inflammation), diarrhea, and dementia. The dermatitis part means pellagra shows up on the skin as rough, dark, scaly patches, especially on the parts of the body exposed to sunlight. This makes pellagra a skin disease.

Step 3: Check why the other options are not skin diseases.
Anaemia is a blood disorder. It happens when the blood does not carry enough oxygen, usually because of low haemoglobin, iron deficiency, or Vitamin B12 deficiency. It affects the blood, not the skin.
Osteomalacia is a bone disorder seen in adults. It happens due to a lack of Vitamin D and calcium, which makes the bones soft and weak. It affects the skeleton, not the skin.
Rickets is also caused by a lack of Vitamin D and calcium, but it appears in growing children. It leads to soft, bent bones, especially in the legs. Like osteomalacia, this is a bone disease, not a skin disease.

Step 4: Final answer.
Only pellagra, out of the four options, is a disease of the skin. Anaemia is a blood disease, while osteomalacia and rickets are bone diseases caused by Vitamin D deficiency.
\[ \boxed{\text{Pellagra}} \]