My mother has recently developed white patches on her skin that do not tan or burn in the sun. What causes this? Is it a condition that should be brought to the attention of a doctor?
This sounds like a condition called vitligo. The majority of cases occur for no known reason in otherwise healthy people. In a small minority of cases it can occur in association with other conditions such as hypothyroidism, pernicious anaemia and alopecia. The blanching of the skin is due to the disappearance of the melanocytes or pigment cells from the skin. It is sometimes possible to re-pigment the skin but unfortunately such treatment is successful in only a minority of cases. For most people it is a cosmetic defect with no health implications. Your mother should see her GP to have the diagnosis confirmed.