I’ve always been diligent about sunscreen. I wouldn’t be caught dead outdoors without at least two finger-lengths’ worth slathered across my face and I’m equally particular about reapplying when I know I’ll be out for a while.
I’m lucky enough to work from home, though, and this is where my sunscreen routine fell short. I never really saw the point of wearing it indoors, even though my dermatologist had advised me to. I spend most of my day at my desk — at home. Surely, that counted as being safely away from the sun. But then I developed a rash. It was incredibly itchy and scaly and eventually started forming a rough layer over my skin. I have a fairly elaborate skincare routine, moisturise regularly and generally know when something is off, which is what made this particularly alarming.
I tried every moisturiser I had. Nothing helped. The rash was also strangely specific in where it appeared: mostly on my right arm and the right side of my neck. After a few days of trying to manage it myself, I gave up and went to the dermatologist. The diagnosis was polymorphous light eruption or PMLE: a type of photosensitive skin reaction, often referred to as a sun rash.
Then I thought about my desk. I sit beside a large window on my right-hand side. The rash was almost entirely on the side of my body facing the window.
So, can you actually get sun damage indoors?
As it turns out, being indoors doesn't necessarily mean being completely removed from UV exposure. “Patients sometimes tell me they’ve been careful in the sun, but then mention that they spend hours working beside a bright window,” says Dr Nidhi Shah, consultant dermatologist at Dr Rekha Sheth’s Skin and Hair Clinic. “Glass blocks most UVB, but UVA can still get through. For someone prone to PMLE, that indoor exposure can matter. I usually advise them to protect their skin with a broad-spectrum sunscreen, a change of seating or UV-protective window film.”
UVB is the type of ultraviolet radiation primarily responsible for sunburns, while UVA penetrates deeper into the skin and is associated with photoageing and skin cancer. Ordinary window glass blocks most UVB, but UVA transmission depends on the type of glass.
How much UVA reaches you also depends on how close you are to the window, whether direct sunlight is falling on you, the time of day and season. In my case, sitting beside a large window for several hours every day, with the afternoon sun falling directly onto my right side, gave me PMLE.
Does everyone need sunscreen indoors?
This is where things get more nuanced.
Dr Nidhi Shah puts it rather nicely: “If you spend your day away from direct sunlight, there’s no need to treat your living room like the beach. It’s really about where the light falls and how long you’re there.”
Dr Sunitha Mohan, dermatologist at Neothera, says she is particularly careful about recommending daily sunscreen for people who are prone to pigmentation, melasma or post-inflammatory hyperpigmentation, as well as those with sensitive or compromised skin. Yet, she goes on to say, “For the average person sitting indoors away from direct sunlight, [UVA exposure is] probably not enough to be a major concern except for those with underlying skin conditions”.
In other words, there isn't a universal rule that everyone needs to spend their workday indoors covered in sunscreen.
What about cloudy days and quick trips outside?
Dr Mohan points out that our exposure is rarely as predictable as we think. “You may step out for a few minutes, walk to your car, sit near a window, run an unexpected errand or have incidental exposure. Hence, as a dermatologist, I generally recommend building sunscreen into your daily routine. Consistency makes protection effortless and helps prevent those small exposures, particularly for people concerned about pigmentation.”
She also stresses that reapplying sunscreen repeatedly while sitting indoors isn't necessary. The goal is sensible protection, rather than turning every room into a sun-protection zone.
What I do now
I still spend the same amount of time by the window and I still work at the same desk — just considerably greasier from all the sunscreen.
The rash returns every now and then when I stop being careful. And while I’m still not convinced I need to wear sunscreen every time I sit inside my house, I no longer think of being indoors as a complete escape from the sun.