Fever is one of the body’s most original defenses against infection or assault. The technical definition, for medical practitioners, defines this as a core body temperature of 100.4-100.9 F, which is about 3 degrees higher than what is considered a normal temperature. Other terms, such as hyperthermia and pyrexia, are also used interchangeably, although the understanding of these two terms does not have any precise definition. However, what is more useful and interesting to understand is what causes a fever and why it is occurring.
When the body notices a foreign intruder, such as bacteria (known as sepsis), it releases tiny components of the immune system that act on the brain as a signal to increase temperature. This area of the brain is always in direct contact with circulating blood in the body, which renders it capable of performing this form of surveillance.
Sometimes, toxins produced by bacteria can act on this area of the brain directly to trigger this response. This is actually a very fine-tuned evolutionary mechanism which raises temperatures above what bacteria and fungi can survive without harming body cells themselves, as well as allows for key parts of the immune system to become widely circulated. In a fortunate coincidence, antibiotic drugs also work better at these higher temperatures.
When raising the temperatures does not resolve the assault to the body, the body attempts to raise the stakes by continuing to raise the temperature. When temperatures go above 106.7 F, or when they are raised for a chronic period of time, this response outlives its evolutionary benefit, and harm starts to occur to the body. This is seen in drug reactions, chronic inflammatory conditions, and infections that are not easily combated by raised temperatures. When unnatural changes to body chemistry occur, this can be a result.
Alcohol withdrawal syndrome, which is a subset of what is considered in a wider sense Alcohol Dependence Syndrome, occurs after cessation of alcohol ingestion following a prolonged use of alcohol consumption. Upon ending alcohol use, individuals may notice a number of symptoms. The most common of these are tremors, restlessness, insomnia, fast heart rate, and sweating. In severe cases, these symptoms do progress as far as hallucinations or seizures. The reason for this comes from alcohol’s natural properties as a sedative. Alcohol decreases activity within the front of the brain, which is the area responsible for inhibition and complex decision-making.
When the presence of alcohol becomes an accustomed event, the body responds by making more activity at its baseline. Thus, when alcohol is then removed from the system, what is left is a hyperactive brain. When the brain becomes hyperactive, the energy directs bodily functions at an increased rate, which physicians would call being out of homeostasis. It is this excess energy that causes the symptoms of withdrawal.
Some of the ways that the brain directs excess energy are apparent in the symptoms; sweating, increased heart rate, and tremors are all activities that normally burn energy, and would make sense to be increased in a hyper-excitable state. In fact, it would be difficult to differentiate this from an actual fever, as it would look very similar without measuring a person’s temperature. More severe symptoms, such as hallucinations and seizures, are the result of aberrant excitation of the brain without anywhere to direct the energy. These tend to occur in days 2-4 of detoxification, and are usually following earlier signs such as hand tremors.
Unfortunately, the question of whether alcohol withdrawal causes a fever is a little more complex than a yes or no. Mild fever itself is considered an inconsistent but possible early sign of alcohol detoxification. It is listed as a 1st degree symptom (degrees of alcohol withdrawal are numbered 1-4 according to their severity), much like those of tremors, increased heart rate, and sweating, but is not needed for a diagnosis of alcohol withdrawal.
This is likely not a typical process that the body employs a fever for, which is to fight infection, but is more so the result of all of the body’s metabolic functions being up-regulated. Up-regulation of the body’s metabolism is a known source of increased body temperature, but acts somewhat differently than a true fever, in that it is the energetic components of the body that cause the overall raised temperature, not a deliberate attempt to eliminate a foreign presence.
A study of 110 patients undergoing alcohol withdrawal treatment was carried out in Europe, and increased body temperature was seen in 60% of them. However, the inclusion criteria for raised body temperature was 98.6-100.22 F, which starts the inclusion below the correct diagnosis of a fever.
Additionally, in 60% of these patients with fever, there was an identified cause outside of the withdrawal itself. Many of these patients, while in the hospital, acquired an infection, or had an inflammatory response to their IV site, which is known in medical terms as phlebitis. When the fever continued to rise in these patients beyond day 3, it was associated with the more severe withdrawal symptoms of hallucinations and seizures.
Although information on fever in alcohol withdrawal remains somewhat scarce, clinically it is still included as a symptom. This is because it is thought to be an accessory symptom to the more visible symptoms of tremors and sweating, in most cases does not harm the body, and is usually handled fairly easily with medical management. If a fever goes beyond mild into the more severe, or is not resolved by day 2 or 3, then this is considered a more interesting finding, and doctors will move to find an underlying source, like an infection, or will use this as an indication to treat the withdrawal more aggressively. In most cases of withdrawal this does not happen, so it becomes a useful sign of a need for some closer management. Thus, it is a great symptom to monitor, and usually will not be severe.
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