Acne marks after pregnancy and new patches on the nose are very common in the months after delivery. Yes, please use sunscreen every day. Sun exposure darkens pigmentation and slows any fading. Dry skin does best with a gentle, fragrance-free routine and a good moisturiser. Pigmentation fades slowly, so give your routine a few months to show a change.
Next Steps
Since a small blister came up after a thicker layer of your night cream, hold off on that cream and message your dermatologist before using it again. They can confirm whether each product suits your dry skin. Tell them if you are breastfeeding, so everything can be checked for that too.