10th July 2023

A 21-year-old woman has recently returned from a hot holiday and is concerned about the newly changed colour of her skin

A 21-year-old woman has recently returned from a hot holiday and is concerned about the newly changed colour of her skin (see image below). You diagnose vitiligo. You organise a blood test and note the positive results: Hb 105, MCV 117, megaloblasts on the blood film and B12 deficiency.

Skin colour change

In view of the blood results, what is the most appropriate test to confirm the diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.