a 36-year - old woman presented with a history of asymptomatic patches on her legs . physical examination revealed reticulated , reddish - brown macules with an ill - defined border on the anterior aspect of both thighs ( fig . 1 ) . the patient denied prolonged contact with any heat sources . upon detailed questioning , she eventually recalled having worked with a laptop computer on her thighs for approximately 1 h every day over the past 18 months ( fig . similar skin changes are known as erythema ab igne ( eai , erythema from fire ) after chronic exposure to subliminal levels of infrared radiation insufficient to cause burns . the typical reticulated erythema initially appears reddish , and gradually turns brownish due to increased pigmentation . microscopic changes of eai include hyperkeratosis , epidermal atrophy , squamous atypia , and interface dermatitis with necrotic keratinocytes [ 1 , 2 ] . an accumulation of dermal elastotic tissue , which represents an early sign of both uv radiation- and heat - induced skin damage , may also be seen . rare cases of squamous cell carcinoma and merkel cell carcinoma arising in lesions of eai have been reported . progression of the disease can only be halted by the avoidance of further heat exposure . historically , eai was commonly seen on the shins of individuals working in front of coal stoves or sitting close to a fireplace . overall , the incidence of classic eai has decreased since the introduction of central heating . localization of the lesions corresponds to the different sources of heat that are currently in use . in the more recent past today , unintentional and unperceived exposure to heat from laptop computers needs to be considered as a potential trigger . for this modern - age version of classic eai a rising number of laptop - induced cases of erythema a computatro have been reported recently . most cases were induced by heat radiating from the optical drives of the laptops and thus involved only one leg . the rising incidence of erythema a computatro requires physicians to be aware of the clinical significance of unintentional heat exposure through laptop computers . laptop users should be alerted to this condition and abstain from placing laptops on top of their lap for prolonged periods of time . the authors declare that they have no financial and personal relationships with other people or organizations that could inappropriately influence this work .
historically , erythema ab igne ( eai ) was commonly seen on the shins of individuals working in front of coal stoves or sitting close to a fireplace . in the more recent past , this condition has been primarily observed after repeated application of heating pads . today , unintentional and unperceived exposure to heat from laptop computers needs to be considered as a potential trigger . 
 a rising number of laptop - induced cases of eai have been reported recently . 
 for this modern - age version of classic eai , we propose thus the more accurate neo - latin term erythema a computatro .