Doctors have linked a mysterious rash on a young boy’s abdomen to prolonged heat exposure from a laptop, highlighting a little-known risk associated with everyday technology use. The unusual case, described in BMJ Case Reports, shows how repeated exposure to relatively mild heat can damage the skin without causing a classic burn.
The child arrived at an emergency department with what appeared to be spontaneous bruising across his upper abdomen. Neither he nor his parents could recall an injury, and initial investigations, including X-ray and CT scans, ruled out internal trauma such as liver damage.
Clinicians observed a 15-centimeter flat, reddish-brown patch on the right upper abdomen. The lesion had a distinctive net-like, lace-pattern appearance, but the absence of pain, itching or systemic illness initially made the cause difficult to identify.
Unmasking toasted skin syndrome
Several weeks later, the boy returned with a larger, darker and more tender rash spreading across his abdomen. The changing pattern and discoloration prompted doctors to reconsider possible environmental and behavioral exposures that might previously have been overlooked.
During more detailed questioning, the boy revealed that he was being home-schooled and used a laptop for as long as eight hours each day. Crucially, he frequently rested the device directly on his bare abdomen, particularly while the laptop was plugged in and charging.
With this information, clinicians recognized the condition as erythema ab igne, commonly known as toasted skin syndrome. The diagnosis explained the characteristic net-like rash, which results from repeated exposure to heat that is not intense enough to cause an acute burn but can gradually damage the skin.
How everyday devices cause harm
Erythema ab igne has traditionally been associated with heat sources such as open fires, space heaters, hot water bottles and heating pads. In recent decades, laptops and other electronic devices have emerged as modern triggers, particularly when they remain in direct contact with the skin.
The condition can develop when skin is repeatedly exposed to temperatures generally between 43 and 47 degrees Celsius. At these temperatures, people may experience only mild warmth rather than pain, meaning they might not recognize that their skin is being affected until visible changes develop.
Most reported laptop-related cases involve the thighs, where devices are commonly rested during work or entertainment. In this case, the boy’s habit of reclining with the laptop directly on his abdomen resulted in an unusual location for the injury and made the initial diagnosis more challenging.
Risks, recovery and long-term concerns
Once doctors identified the source of the heat, they reassured the family that the condition was benign and advised the boy to immediately stop placing the laptop directly against his skin. Without continued heat exposure, the rash gradually faded and eventually resolved completely.
Dermatologists caution, however, that chronic or long-standing erythema ab igne may not always be harmless. Persistent cases have been associated in some reports with an increased risk of skin cancers, including squamous cell carcinoma and Merkel cell carcinoma, developing within the affected area.
Experts therefore advise taking persistent skin changes seriously. If the mottled reddish-brown pattern does not improve after the heat source is removed, or if nodules or ulcers develop within the affected skin, medical evaluation and potentially a skin biopsy may be necessary.
Remote work and rising exposure
Researchers warn that toasted skin syndrome could become increasingly relevant among both children and adults. Increased device use for home-schooling, gaming, streaming and remote work since the COVID-19 pandemic has encouraged longer periods of laptop use on couches, beds and laps.
Children and teenagers may be particularly vulnerable because of extended screen time and limited awareness that devices producing only moderate warmth can still expose the skin to damaging heat over prolonged periods. Heating pads and hot water bottles can present similar risks when used repeatedly.
Health professionals recommend simple precautions, including placing laptops on desks or stands, using protective barriers such as trays and avoiding prolonged direct contact between warm electronic devices and bare skin. Extra attention may be warranted while a laptop is charging or operating under heavier workloads, when it can generate more heat.
The boy’s case illustrates how a seemingly harmless everyday habit can produce an unusual clinical presentation. For clinicians, it highlights the importance of asking about exposure to modern heat sources when investigating unexplained patterned skin changes. For families, it provides a reminder to consider not only how long laptops are used, but also where they are placed.
