General Practitioner Questions Fever

Low grade fever for long time

One of my aunt's is suffering form low grade fever for a long time (around 30 days ). When the medication is going on, there is no sign of fever but when the medication is stopped fever strikes back again . The fever is around (99-101). Multiple doctors have checked but no one can find out the reason behind it. There are multiple tests done including blood , phenomena, bronchitis, TB etc but every report was false.

Female | 52 years old
Complaint duration: 26/10/18
Conditions: Low grade fever

2 Answers

This is something we call fever of unknown origin. Typically this can only be diagnosed if typical causes of infection are ruled out including pneumonia, urinary tract infections and abdominal infections. The other common causes of low grade fever involve more indolent processes such as fungal infections(geographic), helmith infection, viral infection, autoimmune diseases and cancer. The tests that should be consider are typically selected for the background of each patient specifically. A lot of times we are unable to identify a source and the patient is then labeled as having fever of unknown origin.

I'm not sure what medication you are referring to which helps with the fevers but that could indicate the underlying issue. Sometimes antibiotics help with symptoms but don't resolve the problem if there is an underlying infection of a foreign object or fluid collection such as an abscess or pleural(lung) fluid collection. Some patients suffer from an inherited condition called familial mediterranean fever which is typically one of the last resort screening tests ordered.

Hope this helps,

Jack Stephens, MD
The MOST COMMON cause of chronic fever, especially if more than 6 weeks have elapsed and NO CAUSE is found, is found "FUO" (FEVER OF UNKNOWN ORIGIN). But this is only after common causes are ruled out, like urinary, abdominal, or lung infections have been ruled out, and there is no drug on board that can cause fever (called "DRUG FEVER").

IF all these common and easily diagnosed and treated diseases have been ruled out, then you need to look for the 3 main causes of FUO: infection< tumor, collagen vascular DZ.

1) INFECTION: TB, AIDS, ENDOCARDITIS (infection of heart valve) and abdominal/liver/lung/kidney abscess/infection needs to be looked for (IF the patient is from out of the country, malaria, typhoid, and TB may need to be ruled out depending on what country the patient is coming from).

2) TUMOR: Usually meaning LYMPHOMA/LEUKEMIA, but other solid tumors -- lung, liver, kidney, breast, colon, pancreatic, etc. -- can rarely do this, too, and may need to looked for, depending on the clinical scenario and whether the patient has any focal symptoms that may be a clue to the source of the problem.

3) CVD: like lupus, rheumatoid arthritis, vasculitis (like giant cell arteritis, polymyalgia rheumatica, polyarteritis, ANCA vasculitis)

Depending on the results of the preliminary tests and the clinical context -- blood tests, blood cultures, sed rate, CXR, urine cultures, and maybe abdominal imaging -- these all need to be considered. If one knew what drug appears to be suppressing the fever, like an antibiotic, NSAID/Tylenol, or steroids, this might clue one in to the source of the problem. If an antibiotic seems to be suppressing the fever, then there probably is an infection going on and blood cultures (OFF ANTIBIOTICS), urine cultures, CXR -- all need to be done. Imaging studies like CT or MRI may be indicated if there are focal symptoms or history or physical exam (or a blood test) suggests where the source is.