Definition
Sunstroke, also known as insolation, is a reaction of the body to a previously prolonged exposure to the sun on the unprotected head or neck. The main cause of symptoms such as headache or nausea is the heat transmitted by the sun’s rays, which is accompanied by increased irritation of the brain and especially the meninges. Sunstroke can also be described as an isolated heat stroke of the head, this expresses well the underlying heat component of the developing symptoms. Nevertheless, one distinguishes sunstroke from heat stroke, which is more dangerous and is accompanied by a complete increase in body temperature – this does not usually occur with sunstroke.
Causes
A prolonged exposure to the heat transmitted by the sun causes irritation of the brain and meninges in the course of a sunstroke. The unprotected head reacts to heat by dilating the blood vessels, the blood volume apparently decreases, because the dilation increases the blood-carrying space of the blood vessels. In addition to the irritation caused by heat, there is also a slight inflammatory reaction in the area of the brain and the meninges, which additionally causes the pain symptomatology of sunstroke. The long suspected assumption that UV radiation is the cause of sunstroke could not be proven to be the trigger, so that today only the increased heat stress in the head and neck area is seen as a problem. Frequently concerning see themselves by apparently cooling measures, like stay in the water or in height regions with migrations not substantially the sun exposed, nevertheless the symptoms of a sun stabbing can impress here after some hours nevertheless.
Diagnosis
The diagnosis of a sunstroke can be quite difficult for the examiner because the symptoms can often resemble meningitis. Irritation of the meninges by heat can be accompanied by neck stiffness, just as in meningitis. Symptoms such as nausea, headache, physical and mental restlessness also confirm the overlap of the two clinical pictures.
At the beginning of all diagnostics, the patient’s medical history is taken, which includes questions about the duration of sunbathing and accompanying activities. Also the question of contact with possible cases of meningitis that may have occurred in the vicinity should not be omitted. Possible tick bites should be included in the expertise. These two courses of events should therefore be excluded in order to avoid potentially averted disease progression.
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