Hi there... Greetings.
If you hail from Bangalore, it has been cold here last few weeks and that could have added to your particular situation.
A more detailed history and medical evaluation is required to rule out systemic causes for this pigmentation
Contact allergy history, medication history of any, habits (eg smoking 🚬) etc have to be all factored in to see if any correlation exists and treatment will have to be tailored accordingly 🙏
Next Steps
An Online or in-person Consultation as per your preference and convenience ASAP
Health Tips
Avoid licking lips 👄
☀️ protection; use a 🧢 in addition to any good quality sunscreen that you probably already have but use it dawn to dusk.