02/09/2026
The damage doesn’t stop when the redness does.
UVB is absorbed directly by DNA, fusing adjacent bases and distorting the strand. Repair mechanisms correct most of it — but repair is not complete, and it isn’t guaranteed.
UVA travels further. It works indirectly, generating reactive oxygen species that damage lipids, proteins and DNA throughout the dermis.
That oxidative signal reaches the fibroblast and changes what it produces: matrix metalloproteinases are upregulated, procollagen synthesis is suppressed. Collagen fibrils fragment. Fibroblasts lose their anchoring, collapse, and produce less — so the process reinforces itself.
The clinically relevant part: none of this requires visible erythema. Skin can present as settled while the matrix beneath remains disorganised.
Which is why the returning holiday client is an assessment, not an assumption.
Save this for your September consultations.