9 Reasons For Low Grade Fever In Kids: Symptoms And Treatment

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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). It’s important to note that these temperature ranges can vary from child to child.

Children may contract a fever due to several factors, ranging from changes in the weather to an underlying infection. If your young one 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.

Understanding fever is important because it may signal the body’s response to infections or other health problems. By tracking fever patterns, parents can know when to seek medical help and ensure their child’s health is properly managed. 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

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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.

1. 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).

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).

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, immunizations 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 immunization 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).

Julia, a mother of four children, discusses how her son Truman often gets a low-grade fever after vaccinations. She recounts, “Truman has always been a kid that feels teething and vaccines. After his 15-month shots, he had a low-grade fever and was super fussy, and then he had a little bug of some sort, too, with another low-grade fever and even more fussiness (i).”

Quick fact

The drug-induced fever generally begins seven to ten days after drug administration and lasts until the drug is continued. The fever disappears once the drug is discontinued and reappears when it is restarted (4).

4. 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).

5. Stress: A low-grade fever caused by psychological stress is called psychogenicⁱSomething that has a psychological origin instead of a physical origin fever. According to the American Institute of Stress, family conflicts could increase the risk of illnesses, which could cause a fever (8).

6. 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).  According to the CDC, in 2021, children under 15 years of age accounted for 4% of tuberculosis (TB) cases in the United States. Specifically, there were 317 cases of TB disease among children aged 14 years or younger that year. , in 2021, children under 15 years of age accounted for 4% of tuberculosis (TB) cases in the United States. Specifically, there were 317 cases of TB disease among children aged 14 years or younger that year.

7. 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).

8. 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).

9. Other infections or chronic diseases: Here are a few other infections that could cause a low-grade fever (12).

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• 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) (13).

• Decreased frequency of urination
• Dehydration (when loss of body fluids is more than the intake)
• Headache
• Body pain
• Sunken eyes
• Dry mouth
• Loss of appetite

When To See A Doctor

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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,
• PhotophobiaⁱHeightened sensitivity and discomfort in eyes due to bright light (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
• AnorexiaⁱAn eating disorder characterized by unusually low weight, fear of weight gain, or trying hard to lose weight (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

Be watchful

Do not ignore your child’s fever if it is accompanied by symptoms such as blue lips, tongue, or nails, stiff neck, and drooling (22).

Diagnosis Of Low-Grade Fever

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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 (17).

• Digital thermometer, which is placed under the tongue or armpit or inserted into the rectum
• TympanicⁱRelated to the eardrum (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.
Parents may also consider keeping a record of their child’s fever patterns, noting any related symptoms. This can provide the healthcare provider with detailed information during consultations, helping with accurate diagnosis and treatment planning.

Treatment For Low-Grade Fever In Children

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If viral infections in children cause a low-grade fever, proper rest, drinking plenty of fluids, and taking 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 syndromeⁱA rare disorder that affects multiple organs and leads to severe liver and brain damage. (18) (19).

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.

Quick tip

Do not use rubbing alcohol, ice packs, or cold baths to reduce the fever. While rubbing alcohol may be poisonous when absorbed through the skin, ice packs or cold baths may cause chills that can increase children’s body temperature (22).

Infographic: When You Should Not Worry About Your Child’s Fever

Fever in children can be worrisome, and a low-grade one may not necessarily mean that the illness is not concerning. However, there are specific apparent indications that can help you relax and not panic about your child’s fever. So use this infographic to spot the signs of an unalarming fever and prevent inessential medications.

Illustration: Momjunction Design Team

Illustration: Reasons For Low Grade Fever In Kids: Symptoms And Treatment

Image: Dall·E/MomJunction Design Team

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Reviewer Author Editor Fact Checker

Dr. Kishor TewaryMD

Dr. Kishor Tewary is a senior consultant pediatrician with a special interest in pediatric urology and nephrology and holds 35 years of experience. After obtaining his MD from Patna University in 1989, Dr. Tewary served at Holy Family Hospital, Patna as a consultant pediatrician and nephrologist till 1996.

Read full bio of Dr. Kishor Tewary

Sindusha MSMSc (Food & Nutrition)

Sindusha is a clinical nutritionist with over two years of experience in diverse fields of nutrition. She did her Masters in Food Science and Nutrition from Avinashilingam Institute for Home Science and Higher Education for Women and has qualified UGC-NET.

Read full bio of Sindusha MS

Dr. Ritika ShahBDS, CLC

Dr. Ritika Shah is a certified lactation counsellor (CLC) from iNational Health Care Academy, Singapore and a dental surgeon with more than seven years of clinical experience across various cities in India. She did her graduation in Dentistry from KM Shah Dental College.

Read full bio of Dr. Ritika Shah

Dr. Joyani DasM.Pharm, PhD

Dr. Joyani Das did her post-graduation from Birla Institute of Technology, Mesra and PhD in Pharmacology. Previously, she worked as an associate professor, faculty of Pharmacology, for two years. With her research background in preclinical studies and a zeal for scientific writing, she joined MomJunction as a health writer.

Read full bio of Dr. Joyani Das