Hi and thank for the question,
the decrease in sensitivity could could arise form a vast majority of sources. A fungal infection
left untreated could lead to a transient decrease in sensitivity. Other causes like leprosy
lesions in this could really be very less probable.
Visiting a dermatologist
would be of much help in ascertaining the cause. A physical examination and a few exams will make things clearer and facilitate appropriate and more specific management schemes.
i therefore suggest you book an appointment with your nearest dermatologist.
Thanks for using health care magic and hope this helps,