1791
Known as hot water bottle rash, fire stains, laptop thigh, granny’s tartan and toasted skin syndrome.
It is a skin condition caused by long-term exposure to heat radiation.
Women have a higher incidence of than men.
Prolonged thermal radiation exposure to the skin can lead to the development of erythema, hyperpigmentation, scaling and telangiectasia.
Some patients may experience itchiness and a burning sensation.
Types of heat sources that can cause this condition are:
repeated application of hot water bottles,
heating blankets or heat pads to treat chronic pain,
repeated exposure to heated car seats, space heaters, or fireplaces.
Resting a laptop computer on the thigh
Occupational problems include: silversmiths and jewellers, bakers and chefs.
The pathogenesis remains unknown.
Suspected thermal radiation exposure can induce epidermal damage to superficial blood vessels that subsequently leads to vascular dilation.
Subsequent hemosiderin deposition can occur in a reticular distribution.
The vasodilation of vessels presents as observed erythema.
Red blood cell extravasate and the deposition of hemosiderin appears as hyperpigmentation.
The distribution of affected blood vessels in the superficial subcutaneous plexus of the papillary dermis results in the net-like pattern of erythema ab igne skin lesions.
The initial treatment is discontinuing contact with the heat source.
In mild disease with slight redness, the condition may resolve itself in a few months.
When the process is severe with skin pigmentation and atrophy, resolution is unlikely.
It may lead to squamous cell carcinoma or a neuroendocrine carcinoma such as a Merkel cell carcinoma may form.
The abnormal pigmented skin may persist for years.
Treatment with topical tretinoin or laser may improve the clinical findings..