Fever FAQs

Can fever be prevented?

Fever as a result of an infectious condition can be dramatically reduced in the following ways:

• Hygiene habits: Regular handwashing before eating, or after petting animals or using the toilet is vitally important when it comes to viral and bacterial infections. Handwashing throughout the day in between using public transportation or touching various surfaces is also a good idea, especially if you are around someone who is unwell. It is also very important to teach children healthy handwashing habits. You can also get into the habit of carrying hand sanitisers or antibacterial wipes with you if areas you frequent are not effectively hygienic or clean.
• Be mindful of virus transmission: If you are around someone who is unwell with an infectious condition, it is a good idea to be mindful of touching your nose, mouth or eyes. Infections are typically spread this way. If you, yourself are down with an infection, you can be mindful of spreading it when you cough or sneeze. You can also be mindful of sharing eating utensils, hygiene products, towels, clothing, water bottles or cups.
• Ensure you are properly immunised: Ensuring that you are immune to various diseases or infectious conditions can also go a long way in preventing fevers which can be complex or become serious. If you are travelling, appropriate vaccinations and preventative medications will help reduce any risk.
• Be mindful of strenuous exercise: If you’re active and enjoy a little strenuous exercise activity, ensure that you are sufficiently hydrated, take frequent breaks, wear cool clothing that is not restrictive or that encourages your body to overheat, as well as cool down effectively after your workout.
• Refrain from excessive use of alcohol and illicit drugs

What is a ‘fever of an unknown origin’?

It can happen that a distinctive cause of fever is unknown, even after extensive testing. When fever peaks at 38.3 degrees Celsius (101 degree Fahrenheit) and persists for more than 3 weeks or occurs frequently without any apparent explanation, a doctor may classify this as a ‘fever of unknown origin’ (FUO).

An FUO can be classified as:

• Classic: An unexplained fever that lasts 3 weeks can be classified as a classic FUO. This type of fever is commonly seen in previously healthy individuals as a result of conditions such as leukaemia or diseases that affect connective tissue in the body.
• Nosocomial: This type of FUO is typically seen with individuals who have been hospitalised for something unrelated. The fever that develops is not likely caused by what they were admitted for and appears to be unexplained.
• Immune-deficient: This classification type generally affects those with already compromised or weakened immune systems and whom are at increased risk of infection. This can affect individuals who are already treating a condition affecting the immune system or going through a treatment process, such as chemotherapy.
• HIV-associated: The condition of HIV itself can cause fevers in a sufferer. A weakened immune system can make a person more susceptible to other infections and fevers which may be unexplained, however.

FUO causes

A doctor may diagnose a fever as an FUO, but is likely to continue trying to determine an underlying cause. This is one reason why a doctor will look for specific elements (along with other symptoms which may provide clues) so as to classify a FUO as they go through steps to try and determine a cause. Once a doctor recognises a classified FUO type, he or she may look for signs that help narrow down possible causes. These categories can possibly point to:

• Infections (such as tuberculosis, Lyme disease, or cat scratch fever)
• Inflammation (such as lupus or rheumatoid arthritis)
• Malignancy (such as pancreatic carcinoma or lymphoma)
• Miscellaneous (as a result of illicit drug use or conditions such as hepatitis, hyperthyroidism or others that don’t relate to any other category classification)

Clinical tests are likely to happen as a process of elimination to rule out possibilities as well as to try and determine a cause. It can sometimes happen that an otherwise undiagnosed condition is discovered through a testing process for a FUO and ultimately produces a clear result as to why the fever occurred in the first place. Tests can include culture tests (urine, sputum and blood), and imaging tests (X-rays or endocardiograms).

Any recommended treatment will largely depend on the cause (if found). Sometimes a FUO resolves itself eventually. Your doctor will guide you as to the best way to handle the fever and help to effectively treat any other red flag symptoms that may occur. Medications, such as NSAIDS (non-steroidal anti-inflammatory) and antihistamines may be prescribed to help reduce a fever, even if an underlying cause is not determined. Antibiotics may be prescribed where a FUO is suspected as having originated from an immune-deficient related cause.

Sometimes a cause is never diagnosed. In all cases, a person will be carefully monitored and treated by medical professionals so as to effectively clear a fever.

What is a 'febrile seizure' and how does an elevated temperature in children cause it?

A complication for young children (often between the ages of 6 months to 6 years), a febrile seizure can occur when a child’s body temperature increases rapidly (rising too quickly or spikes). Febrile seizure is also known as a febrile fit or febrile convulsion.

Children who develop ear infections or respiratory viruses such as the common cold can sometimes experience febrile seizures. It can also happen that children who develop more serious conditions, such as pneumonia and kidney infections can also experience rapid body temperature increases. Seizures can occur on the same day a fever develops.

Seizures which happen as a result can be classified as:

• Simple febrile seizures: These last between 5 and 15 minutes and typically don’t occur again within a 24-hour period. A seizure (a generalised tonic-clonic seizure) affects the entire body, whereby stiffening occurs and limbs twitch. A child may lose consciousness but their eyes can remain open during a seizure. Breathing can also become irregular and vomiting and defecation can occur.
• Complex febrile seizures: A seizure can last for a longer period of time and recur. These typically only affect a portion of the body, but can be more serious than a simple febrile seizure.

As frightening as it can be to witness a child experiencing a seizure, this fever-induced complication does not typically result in an ongoing problem. With prompt medical assistance, a child can be effectively treated and their body temperature sufficiently controlled until well again.