Children’s normal body temperature ranges from 97.5°F to 99.5°F (36.4°C to 37.4°C). Low-grade fever in kids occurs when the body temperature is between 99.6°F and 100.3°F (37.5°C to 37.9°C). Alternatively, a fever occurs if the temperature is 100.4°F (38°C) or above (1). Children may contract a fever due to several factors, ranging from changes in the weather to an underlying infection. If your child is experiencing a low-grade fever but seems energetic and continues their normal activities, resting for a while will help them recover. However, if other symptoms accompany the low-grade fever, medical intervention is needed. Read this post to learn about the causes of low-grade fever in children and the symptoms to look out for.
Causes Of Low-Grade Fever In Children
A low-grade fever could mean that your child’s body is trying to ward off an infection or an underlying disease. The following are some of the common reasons behind a low-grade fever.
- Respiratory infections: When viruses and bacteria cause respiratory infections such as the common cold and influenza, the body tries to destroy such pathogens by increasing the body temperature. However, this protective mechanism against such infections could cause a low-grade fever (2).
- Urinary tract infections: UTIs could be another potential cause of low-grade fever in your child. It is a bacterial infection anywhere in the kidneys, urethra, ureters, or bladder and is characterized by a stinging sensation during peeing. A bladder infection could result in low-grade fever. However, if the infection spreads to the kidneys, other symptoms, such as night sweats, fatigue, chills, and fever above 100.3°F (38°C), may also occur (3).
- Medicines and vaccines: A low-grade fever could be a side effect of a new medication. Such drug fevers could be due to hypersensitivity towards the medicine. Refer to the label of the medications to check if the new medicine could be the cause (4). Similarly, vaccinations are followed by an episode of a low-grade fever. A vaccine usually contains small amounts of inactive microbes that trigger the body’s immune system to strengthen the protective response. Therefore, a low-grade fever 24 hours after vaccination is a good sign, as it suggests the vaccine has been effective. Such fevers last a day or two and can be treated with anti-fever medicines (5) (6).
- Cancer: A persistent low-grade fever for weeks or months could be a symptom of underlying cancers, especially leukemias and lymphomas. A fever is a rare symptom of cancer. If the fever lasts for more than three days, you may alert your medical professional (7).
- Stress: A low-grade fever caused by psychological stress is called psychogenic fever. According to the American Institute of Stress, family conflicts could increase the risk of illnesses, which could cause a fever (8).
- Tuberculosis: TB is an airborne contagious disease spread by the bacteria Mycobacterium tuberculosis. A low-grade fever is a common symptom of tuberculosis in children (9).
- Autoimmune diseases: Usually, the body treats an external agent as a pathogen. But in an autoimmune disease, the body presumes the healthy cells as pathogens and attacks them. Rheumatoid arthritis and multiple sclerosis are common autoimmune diseases in children, and a low-grade fever is a common early symptom (10).
- Meningitis: Meninges are thin membranes that enclose the brain and spinal cord. Inflammation of the meninges due to bacterial and viral infections leads to meningitis, which can further trigger low-grade fever in children (11).
- Other infections or chronic diseases: Here are a few other infections that could cause a low-grade fever (12).
Gastrointestinal infections such as food poisoning or parasitic infections in the GI tract Childhood infections such as mumps (a viral illness that affects the salivary glands), chickenpox (a contagious viral infection that causes blisters on the skin), and measles (a viral respiratory illness caused by rubeola) Tonsillitis (the inflammation of tonsils due to bacteria) Other bacterial throat infections such as scarlet fever (accompanied with a rash) and strep throat Cellulitis (bacterial skin infection) Thyroiditis (inflammation of the thyroid gland)
Symptoms Of Low-Grade Fever In Children
As low-grade fever has multiple etiological factors, and the symptoms could be specific to the underlying cause. Nevertheless, here are a few of the common symptoms (1).
Decreased frequency of urination Dehydration (when loss of body fluids is more than the intake) Headache Body pain Loss of appetite
When To See A Doctor
A child could have a fever ranging between 102°F to 103°F. Sometimes, they may have a fever as high as 103°F and perform their routine activities with regular energy. However, stay vigilant, and if any of the following symptoms accompany a fever, visit your healthcare provider (13) (14) (15).
Sore throat, cough, runny nose, blood in sputum, and fatigue A fever for more than three days Temperature above 104°F Persistent fatigue even after good rest Difficulty in walking and breathing Seems confused or makes no eye contact, Photophobia (fear of light) Seizures No response to fever-reducing pills Pneumonia and bronchitis Viral illnesses such as measles and whooping cough Foul-smelling urine, or pain and burning sensation while peeing Decrease in urine output Anorexia (loss of appetite) Enlarged lymph nodes (swelling seen on the side of the neck) Excessive night sweats Bone and joint pains Headache Abdominal pain, vomiting, and nausea Sudden and unintended loss of weight Unexplained lumps, rashes, and bruises on the body Vision and hearing problems Blood in sputum Fatigue
Diagnosis Of Low-Grade Fever
The best way to diagnose a low-grade fever is by measuring the child’s temperature using a thermometer. You could opt for any of these thermometers (16).
Digital thermometer, which is placed under the tongue or armpit or inserted into the rectum Tympanic (ear) thermometer Temporal artery thermometer, which is placed on the forehead area
Your child’s doctor would ask about the symptoms observed and conduct a physical examination. They may also perform a few blood tests and take a urine sample to check for urinary tract infections.
Treatment For Low-Grade Fever In Children
If the low-grade fever is caused by a viral infection, taking proper rest, drinking plenty of fluids, and having a lukewarm bath are often advised. You could also give them an anti-fever pill, such as acetaminophen or ibuprofen. Children under 17 years should not be given Aspirin as it may cause Reye’s syndrome (17) (18). Based on the type and severity of the infection, your pediatrician may suggest some additional interventions such as antibiotics or antiviral drugs. Antibiotics and increased fluid intake are often suggested for UTI. If the underlying cause is chronic, the treatment would include extensive medical interventions.
