What can be done if the cause is not found?
If all kinds of diagnostic tests have failed to provide any information, it is still important to keep an eye on the fever and its development. Other possible symptoms that may be related to the fever should also be taken into account. In some cases an infection – for example with HIV – is not yet detectable and a blood test should be repeated after a few weeks.
Repeated blood tests by a doctor are advisable if the fever persists. It should be made clear that fever without symptoms can be caused by many different factors. Depending on the cause, the prognosis is good or bad.
In general, however, it can be assumed that the prognosis is good if no cause for the fever could be found within six months. The examination of the blood count is an important part of the diagnosis when it comes to fever without symptoms. The blood count involves counting red and white blood cells and platelets (thrombocytes).
This tells us whether the cells in the blood are normal, too low or too high.A subtype of fever of unclear origin is the so-called neutropenic fever, which can be triggered by certain drugs, for example. This is a drop in the number of neutrophilic granulocytes, which are white blood cells and are important for the immune system. If the neutrophilic granulocytes are reduced in the blood count, fever is often the only symptom. Nevertheless, it is a serious condition, as the immune system is severely weakened by the lack of defence cells and therefore promotes severe infections.
Recurrent fever without symptoms
If the fever recurs, one speaks also of recurrent fever. It is important that recurrent fever that cannot be linked to an infection is clarified. On the one hand, recurrent fever can be caused by an accumulation of pus (abscess) in the body.
Normally, such an accumulation of pus is also noticeable through pain, but can cause no further symptoms at first, especially if it is located on internal organs. In addition, Still’s disease, a special form of rheumatoid arthritis, is a possible cause of recurrent fever. Here, too, further symptoms that accompany the fever are possible.
However, the disease can also manifest itself initially only through fever. Hodgkin’s disease, which is a malignant tumor of the lymphatic system, can also be accompanied by recurrent fever attacks over weeks or months. The inherited Familial Mediterranean Fever can cause recurrent fever spikes lasting up to three days. It often occurs in connection with abdominal pain, but can also occur without it. The first fever attack usually occurs before the age of 20.
