Computer makers have been backing away from using the term "laptop" to describe their portable computers for some time now.
Apple, for example, banished the word from its advertising and technical literature back in 2006, and includes in notebook users' manuals the warning: "Do not leave the bottom of your MacBook Pro in contact with your lap or any surface of your body for extended periods. Prolonged contact with your body could cause discomfort and potentially a burn." Evidently for good, product liability reasons.
On Monday the medical journal Paediatrics released a report from the University Hospital Basel Switzerland's Dermatology Department about the case of a 12-year-old patient who developed a sponge-patterned discolouration, technically called "Erythema ab igne," on his left thigh — the consequence of several months of intensive gaming activity on a laptop computer - for hours a day over several months.
According to the report, "Erythema ab igne, or "toasted skin syndrome" is a reticular, pigmented, sometimes telangiectatic dermatosis caused by prolonged exposure to heat or infrared radiation. In laptop-induced cases, "localization on the thighs and asymmetry are characteristic." The asymmetry is caused by laptop computers typically getting much hotter on one side than the other due to the positioning of internal components. Laptop-induced "toasted skin syndrome" was first described in 2004, a few years after faster, hotter processors began to be used in portable computers.
Doctors at Dalhousie University Health Services and the QEII Health Sciences Centre's Department of Dermatology in Halifax, Nova Scotia, reported a similar case in the Sept. 7, 2010 Canadian Medical Association Journal entitled "Academic branding: erythema ab igne and use of laptop computers," in that instance with a 20-year-old female university student manifesting asymptomatic pigmentation in a net-like distribution on her thighs, and admitting to longtime daily use of a laptop computer positioned on her lap.
That report says Erythema ab igne's benign pattern of hyperpigmentation, which can be caused by exposure to various heat sources, is found in up to three per cent of the population, most instances resulting from repeated exposure (lasting one to several hours) of the skin to heat. The dermal discoloration can can appear as early as two weeks or as late as one year following onset of heat exposure, depending on heat intensity and other variables such as presence of clothing between the skin and the heat source. Treatment may consist of topical 5-fluorouracil cream or laser-removal. Rarely, skin cancer can occur at the site of Erythema ab igne.
"Toasted skin syndrome" isn't the only health hazard that's been associated with laptop use. Back in the early '00s, a report entitled "Increase in Scrotal Temperature in Laptop Computer Users," published in the UK journal Human Reproduction by Dr. Yefim Sheynkin of the State University of New York at Stonybrook, noted that when men use laptop computers on their laps, a combination of factors elevates temperatures around their genitals, which over time can result in decreased sperm production – jeopardising fertility. Factors cited were heat generated by the laptop as well as unnatural posture with knees squeezed together in order to balance the laptop on users' laps.
Another study at the Aberdeen Fertility Centre, University of Aberdeen, found that sperm counts fell by nearly 30 per cent among a test group of 7,500 men between 1989 and 2002, a timeline suspiciously coinciding with the growing popularity of laptop computers.
What we can take away from all this is that if one intends using their hot (literally as well as figuratively) notebook for protracted periods in laptop mode, prudence dictates interposing an inexpensive laptop desk product such as ones made by LapWorks or Xpad between computer and thighs