A pre-teen boy in England developed a lace-like rash on his stomach after resting a laptop on his bare abdomen for up to eight hours a day, often while it was charging. MedicalDaily reported the case earlier this month. What has drawn less attention is that laptop makers already warn against that kind of use.
HP's computer user guide is blunt. "To reduce the possibility of heat-related injuries or of overheating the computer, do not place the computer directly on your lap or obstruct the computer air vents," it warns in a user guide posted on HP's website. The same guide tells users not to let the AC adapter touch the skin during operation.
A Rash That Sent Doctors Looking in the Wrong Place
The case, published in September in BMJ Case Reports by Mara Znagoveanu and Edward Artley of University Hospitals of Leicester in England, involved a reddish-brown, net-like rash about 15 centimeters (6 inches) across. Because the boy had been pushed into a chair while play-fighting about a week earlier, doctors first worried about a liver injury. Blood tests and abdominal scans were normal.
The answer came from his daily routine. He was being home-schooled and used his laptop on his bare stomach for hours at a time. The diagnosis was erythema ab igne, better known as toasted skin syndrome. After he stopped resting the laptop on his body, the rash faded gradually and was gone at a follow-up months later.
In a BMJ Group press release, the authors called device use, particularly during home schooling, "an under-recognised cause of erythema ab igne in paediatric populations."
What the Fine Print Says
Apple's safety information for the MacBook Pro makes a similar point. "Use common sense to avoid situations where your skin is in prolonged contact with a device or its power adapter when it's operating or plugged into a power source," it says.
The guide also says, "If your MacBook Pro is on your lap and gets uncomfortably warm, remove it from your lap and place it on a stable, well-ventilated work surface." It advises users not to sleep with a device or power adapter while it is plugged in, and not to place it "under a blanket, pillow, or your body" when connected to power.
The charging detail stands out. The boy often used his laptop while it was plugged in, which is the situation both companies single out.
In other words, the name "laptop" describes how people use these machines more than how at least some manufacturers advise using them. For children, those instructions sit in documentation that adults rarely open, let alone read to a child.
Apple's guidance also tells people to "take special care if you have a physical condition that affects your ability to detect heat against the body." Children are not named, but they may be absorbed in schoolwork or games and slow to move a warm device or notice gradual skin changes.
Heat That Never Feels Like a Burn
Toasted skin syndrome does not require a burn. According to DermNet, a dermatology reference, limited exposure to heat that is too mild to cause a direct burn produces "a mild and transient red rash resembling lacework or a fishing net." With repeated exposure, it can progress to marked redness, darker or lighter patches and thinning of the skin.
Before central heating, the rash was common in older people who sat close to open fires or space heaters. It also appears in workers exposed to heat on the job, such as bakers, chefs and silversmiths. Modern sources include hot water bottles, heating pads, car heaters and heated furniture, as well as electronic devices.
The main treatment is removing the heat source. DermNet notes that mild cases fade on their own over several months, though pigment changes may last for years. In rare severe or long-standing cases, a type of skin cancer called squamous cell carcinoma can develop, so a sore that does not heal or a growing lump in the area should be biopsied.
A 2025 case-control analysis of the National Institutes of Health's All of Us database, published in Baylor University Medical Center Proceedings, linked erythema ab igne diagnoses to higher odds of several skin cancers. The study showed an association in health records, not proof that the rash causes cancer.
Simple Habits That Break the Cycle
Based on the manufacturers' own advice, families can use laptops on a desk or table, or on a lap desk or tray that keeps the device off the skin. Charging devices should not be used against bare skin, in bed or under blankets.
Parents can also watch for a mottled, net-like pattern on the thighs or abdomen, especially in children who use devices for long stretches. Because the rash can resemble bruising or other conditions, telling a clinician about device habits can help avoid unnecessary tests.
Toasted skin syndrome is usually not dangerous, and it typically fades once the heat exposure stops. Anyone with a persistent rash, a change in skin texture, a sore that does not heal, or a new growth in the affected area should have it checked.
Key Questions Answered
What is toasted skin syndrome?
Also called erythema ab igne, it is a net-like skin discoloration caused by repeated exposure to heat that is too mild to cause a burn.
How did the boy develop it?
He used a laptop on his bare abdomen for up to eight hours a day during homeschooling, often while it was charging.
Do laptop makers warn about this?
Yes. An HP user guide says not to place the computer directly on your lap, and Apple advises avoiding prolonged skin contact with a device that is operating or plugged in.
Does the rash go away?
Mild cases usually fade over several months once the heat source is removed, though pigment changes can persist for years.
Is it dangerous?
Usually not, but severe, long-standing cases can rarely lead to skin cancer, so persistent changes should be checked.
How can families prevent it?
Keep laptops on a desk, table, or lap tray, and avoid using charging devices directly against the skin, in bed, or under blankets.
Published by Medicaldaily.com
