A febrile illness is any condition presenting with fever, which means that the body temperature is over 38 ° C. There are two main ways in which the body may increase its temperature; by increasing the amount of heat it produces (for example, by shivering) and by decreasing the amount of heat it loses to the surroundings. This is different from hyperthermia, where the body temperature is also over 38 ° C, but is due to excessive exposure to heat. Hyperpyrexia is the condition of body temperature over 40 ° C.
Fever is a defense mechanism of the organism, which is activated in response to many pathological conditions. Common causes of fever include:
Fever itself is not dangerous; as it represents a normal response to infection/inflammation, is beneficial and supports the immune system. However, it is always a symptom of an underlying illness, and therefore, its cause should be determined and treated. Hyperpyrexia, on the other hand, is a medical emergency, as its underlying cause is always a serious disease and the temperature may lead to irreversible brain damage, and ultimately, death.
While fever does not require treatment routinely, in symptomatic fevers, home treatment may be appropriate. Anti-inflammatory drugs (NSAIDs), such as ibuprofen (eg. Nurofen), may be used to reduce body temperature, by inhibiting the production of some of the substances (called prostaglandins) responsible for generating the fever. Taking an antipyretic drug, such as paracetamol, is another option, although these medications lack the anti-inflammatory effect. Supportive or symptomatic treatment is also an important part of managing a fever. This includes maintaining hydration by drinking water regularly; as well as using physical aids such as a wet sponge, or cool fan to reduce the body temperature. However, it is important not to become too cold, as this will cause the body to trap more heat.
In males, severe febrile illnesses are a known risk factor for non-obstructive azoospermia. After an episode of high fever, temporary reduction of spermiogenesis or complete absence of sperm in the ejaculate may occur. This leads to reversible infertility, which may persist for about two months. The azoospermia is caused by a disruption of the spermiogenesis without a physical obstruction in the genital tract, and is therefore called non-obstructive azoospermia.
In most cases, the sperm count eventually returns back to normal and fertility is restored.
In females, severe fever may also have an adverse effect on fertility and may lead to spontaneous abortion. However, the impact of febrile illnesses on female fertility is not so clearly documented.
The prognosis of severe febrile illnesses depends on the cause, the patient’s condition and response to treatment. The underlying disease should always be identified in a patient with fever. The consequences of a severe fever on a patient’s fertility are usually temporary and rarely result in permanent infertility, if there is not any concurrent damage to the reproductive system.