Dermatomyositis (DM) is a rare autoimmune disease that affects the skin and muscles, often causing a distinctive rash and muscle weakness. While managing symptoms and medications is a major part of living with DM, one critical but often underestimated factor is sun exposure. For people with dermatomyositis, ultraviolet (UV) radiation from the sun can significantly worsen symptoms and trigger disease flares.
Dermatologist Dr. Victoria Werth, a leading dermatomyositis researcher at the University of Pennsylvania and a member of TMA’s Medical Advisory Board, emphasizes that photosensitivity is a key feature of DM, especially in those with skin-only forms like amyopathic dermatomyositis. “Even minimal sun exposure can lead to significant skin inflammation and disease flares,” she notes.
Here’s why UV exposure is particularly harmful for DM patients:
- Photosensitivity: The immune system in those with DM reacts abnormally to UV light, leading to inflammation and worsening of skin lesions.
- Flare-ups: UV exposure can trigger systemic flares, not just skin symptoms, potentially worsening muscle weakness and fatigue.
- Delayed Healing: The skin in DM patients is often fragile and slow to heal, making sunburns more dangerous.
- Increased Cancer Risk: Chronic inflammation and immune dysregulation may increase the risk of skin cancers, especially in sun-exposed areas.
Sun protection is not optional for those who live with dermatomyositis—it’s essential.
— Dr. Victoria Werth, dermatologist
How to Protect Yourself from UV Exposure
- Cover up with UPF (Ultraviolet Protection Factor) 50+ clothing.
- Opt for long-sleeved shirts, long pants, and wide-brimmed hats.
- Wear sunscreen with 70+ SPF rating every day, even under clothing; choose one with zinc oxide or titanium dioxide to block sun.
- Apply sunscreen even on cool or cloudy days and when driving.
- Reapply sunscreen every 2 hours
- Use UV-blocking umbrellas or canopies when outdoors. But be aware that you still need protection—60% of the sun’s rays reflect off sand and water.
- Enjoy the outdoors before 10am and after 4pm when the sun is not as strong.
- Avoid tanning beds and UV lamps such as those used in nail salons.
- Be aware that some indoor lighting (e.g., halogen or fluorescent bulbs) can emit low levels of UV radiation.
- Check the daily UV index using weather apps or websites, and avoid outdoor exposure when the index is 6 or higher.
Living with dermatomyositis requires a proactive approach to managing environmental triggers—especially sunlight. As Dr. Victoria Werth advises, “Sun protection is not optional for those who live with dermatomyositis—it’s essential. With the right precautions, patients can significantly reduce flares and improve their quality of life.
Be aware that some indoor lighting (e.g., halogen or fluorescent bulbs) can emit low levels of UV radiation. Should you wear sunscreen in front of a computer? Are these light bulbs safe to use, should sunscreen be worn with them?
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I would use warm white not the daylight white. Also, the 100 watt equivalent bulb would bother me. I would use the lowest watt equivalent that you can. Sunscreen even indoors has helped.
More of a question here – what are the knowns about red light / infrared therapy for DM?
Is it safe or should you stay away??
Thanks!
Sarah, according to Dr. Victoria Werth who is a member of our Medical Advisory Board and our Board of Directors, we don’t know much about red light or infrared therapy. The research has not been done yet in the same way UV light has been studied.
I need to share how bad my DM flareup currently is.
Over the last year and three months I developed a very itchy scalp. Nerve moving sensation on the top left side of scalp. I tried everything.
I developed reddish rashes on both my ears in the last two months. My ears look like they are burned. So sensitive to the touch.
Dues to how severe my DM flareup is, the phone use caused the rashes on my ears. I believe when you have severe inflammation, cell phone use is a contributing factor.
I am devoted to wearing sunscreen and large brim spf hats. I do not go out in the sun at all.
The burns/reddish rash is identical on both ears. Which is where I press my cell phone on both ears.
At first I thought I developed a new autoimmune. Then I thought this is getting bad.
I began strong meditations to lower the inflammation yesterday.
I also get my nails done, something I stopped immediately. I did not know that the nail ovens were causing the rashes and pain on my hands. I was burning my hands and didn’t know it.
I am past the denial stage. I have DM. I developed DM the day I was exposed to COVID in 2020. I became very sick and was able to be diagnosed within 3 months of me developing DM. The Covid vaccines were like internal burning poison to my body. I developed heart issues.
I am new to all the DM knowledge.
I hope this helps someone.
I came across your comment and just wanted to share I too started having DM issues post covid vax and worsened with covid infections. I’m having real sore scalp and hair shedding. Massage and oil treatments have helped. My biggest issue is muscle wasting and atrophy across my body but it’s really affecting my back and legs. I’ve not been able to get a diagnosis bc my CK is normal and no major rash. But 2 years into the muscle issues and now getting sunburn skin feeling.
Post shots my initial issues were heart and neuropathy in the arm I got it in. And it’s just continued to spread with time.
I have recently ran a Myositis panel that shows positive for Mi-2 Beta antibody. I assume you did Myositis panel too and which marker showed up? Have you done any further testing for your Myositis diagnosis?
Just know you aren’t alone in the cause of what’s going on. I was healthy and fit and active and now I’m not regenerating any muscles. It’s been absolutely heartbreaking.