Hello. Thanks for your query on healthcaremagic
Acne treatment can make the skin sensitive, specially if it includes topical or oral
retinoids. This makes the skin prone to
sunburn, which can manifest as redness and discomfort.
Therefore it is important to avoid sun as much as possible while you are on acne treatment, specially during that part of the day when the sun is strong (10 AM to 3 PM).
Places such as beach and at high altitudes, the sun is usually strong and therefore you must have got sunburn in spite of using sunscreen.
It is also important to select the right sunscreen, a sunscreen with a higher spf like 30 + would be more effective against sunburn than a sunscreen with a lower spf.
A sunscreen should be reapplied every 2-3 hours to be effective
If I was the treating doctor I would have asked you to use a moderately potent
topical steroid e.g
fluticasone propionate cream 0.05% twice daily at the affected site.
Steroids are rapidly effective in bringing down the redness and discomfort due to a sunburn.
However, this is a prescription product and therefore you must visit a doctor in your region for the needful.
Regards