Lupus erythematosus is an autoimmune disease that affects the skin and other organs like joints, kidneys, and blood. The butterfly rash or the red patch on the cheeks and the bridge of the nose is the most striking presentation of lupus on the skin. Sometimes, it is also accompanied by a rash affecting the neck, chest, and arms that follows a pattern where the sun or light hits the skin. This finding is also known as the photosensitive lupus rash.
In this issue, we speak with an internist and rheumatologist to discuss the skin and systemic effects of sun, light, and heat on patients with lupus. Additionally, we also talk about some practical ways to protect the photosensitive skin.
Questions:
𝐖𝐡𝐲 𝐝𝐨𝐞𝐬 𝐭𝐡𝐞 𝐬𝐮𝐧 𝐦𝐚𝐤𝐞 𝐥𝐮𝐩𝐮𝐬 𝐨𝐧 𝐭𝐡𝐞 𝐬𝐤𝐢𝐧 𝐰𝐨𝐫𝐬𝐞?
A lupus patient’s immune system reacts strongly to the ultraviolet (UV) rays of the sun. This exaggerated immune activation results in inflammation which can be seen on the skin as a red rash or felt by the patients as itching, stinging, or tingling. Some patients also react strongly to indoor lighting, especially that made of fluorescent or halogen bulbs. Heat is also a known trigger. Although the rash could appear within a day, some patients experience worsening of their skin lesions after more than a week of the initial exposure.
𝐂𝐨𝐮𝐥𝐝 𝐨𝐭𝐡𝐞𝐫 𝐨𝐫𝐠𝐚𝐧𝐬 𝐛𝐞 𝐢𝐧𝐯𝐨𝐥𝐯𝐞𝐝?
Since blood circulates from the skin to the rest of the body, cutaneous inflammation triggered by UV rays could reach the other organs. Some patients end up feeling fatigued and getting muscle and joint aches after being out in the sun for too long. There are reports of patients getting abnormal liver and kidney tests, and blood counts after too much UV exposure.
𝐇𝐨𝐰 𝐜𝐚𝐧 𝐥𝐮𝐩𝐮𝐬 𝐩𝐚𝐭𝐢𝐞𝐧𝐭𝐬 𝐩𝐫𝐨𝐭𝐞𝐜𝐭 𝐭𝐡𝐞𝐦𝐬𝐞𝐥𝐯𝐞𝐬 𝐟𝐫𝐨𝐦 𝐭𝐡𝐞 𝐬𝐮𝐧?
Strict avoidance of sun exposure by staying indoors with good ventilation and cooling is primary. Interestingly, UV rays can still enter indoors through the windows, so even this spot is off limits for extremely photosensitive patients. Indoor lighting should be UV-filtered and made of LED bulbs. If sun exposure is anticipated, sunscreen (broad-spectrum, SPF 50 or higher), hats, sunglasses, sun protection vests/shirts are a must. Vehicles might need protective anti-UV film coating, but specifications should follow local regulations to maximize driver and passenger safety. Less UV exposure could cause vitamin D deficiency, so monitoring of vitamin D levels or outright supplementation is encouraged.
𝐖𝐡𝐚𝐭 𝐚𝐫𝐞 𝐭𝐡𝐞 𝐭𝐫𝐞𝐚𝐭𝐦𝐞𝐧𝐭 𝐨𝐩𝐭𝐢𝐨𝐧𝐬 𝐟𝐨𝐫 𝐭𝐡𝐢𝐬 𝐩𝐡𝐨𝐭𝐨𝐬𝐞𝐧𝐬𝐢𝐭𝐢𝐯𝐞 𝐫𝐚𝐬𝐡?
Once the rash is there, photoprotection is not usually enough. There are topical and systemic medications that calm the hyperactive immune system. Talk to your dermatologist and rheumatologist to know more about your options.
