A newly noticed white or lighter spot on the thumb does not necessarily mean vitiligo. Vitiligo usually presents as a well-defined pale or milky-white area due to loss of skin pigment, but other causes of localized hypopigmentation can look similar.
Driving itself is not a typical direct cause of vitiligo. However, repeated friction, pressure or minor trauma to the skin can sometimes be relevant in people who are predisposed to vitiligo.
Next Steps
Since this is a recent finding, I would first confirm whether it is actually loss of pigmentation. Please monitor whether the spot becomes whiter, increases in size, or whether similar spots appear elsewhere. A clinical examination, and if required a Wood's lamp examination, can help distinguish vitiligo from other causes of hypopigmentation.
You can also share a clear, close-up photograph in natural light and mention when you first noticed it and whether it is changing. Based on the complete history and examination, an individualized treatment approach can then be planned.
Health Tips
Don't panic or start treatment based only on a photograph. If the patch is confirmed as vitiligo, early assessment is useful because the course can vary considerably between individuals. Protect any clearly depigmented area from excessive sun exposure.