Which of the following diseases affects the skin?

The disease that primarily affects the skin is Pellagra. Pellagra is a nutritional deficiency disease caused by a lack of niacin (Vitamin B3) or its precursor tryptophan in the diet. This vitamin is essential for maintaining healthy skin, nerves, and the digestive system. When the body does not get enough niacin, several organs are affected, but the most visible symptoms appear on the skin.

Pellagra is commonly described by the “three Ds” — Dermatitis, Diarrhea, and Dementia. The skin symptoms (dermatitis) are among the earliest and most recognizable signs. The affected areas, especially those exposed to sunlight, become rough, dark, and scaly. The skin may also show redness, cracking, and peeling, often resembling a severe sunburn. Over time, the condition worsens if not treated.

This disease was historically common in regions where the diet consisted mainly of corn or maize, which is low in niacin and tryptophan unless specially treated. Today, Pellagra is rare in developed countries but can still occur in areas with malnutrition, alcoholism, or poor absorption of nutrients.

Besides skin problems, Pellagra also affects the digestive system, leading to inflammation of the mouth and tongue, and the nervous system, causing depression, confusion, and in severe cases, memory loss.

The treatment for Pellagra involves improving nutrition and supplementing with nicotinamide or niacin tablets, along with a balanced diet rich in meat, fish, eggs, green vegetables, and whole grains.

In short, Pellagra demonstrates how a single vitamin deficiency can disturb multiple body systems, especially the skin, which often acts as an early indicator of nutritional health. Maintaining a balanced diet ensures proper vitamin intake, keeping the skin healthy and protecting the body from deficiency-related diseases.