Fever: Health Importance Of Its Clinical Characteristics And Accompaniments

The onset may be abrupt as in infections like Pneumonia or it may have a step ladder type of rise as in typhoid fever. When the high temperature falls to normal within a few hours it is called fall by crisis and when it touches the normal, slowly over days it is called fall by lysis.

Several patterns of fever are recognized. These have to be taken into account since the pattern of fever is of immense help in diagnosis.

1. Continuous fever: The temperature is persistently elevated with the diurnal variation less than 1⁰C, eg, typhoid in the second week, typhus.
2. Remittent fever: The temperature is persistently elevated bu the diurnal variation is more than 1⁰C, eg, typhoid in the third week, meningitis and pneumonia.
3. Intermittent fever: The temperature is discontinuous, touching normal at least once in 24 hours. Intermittent fever is commonly seen in pyogenic infections, lymphomas and tuberculosis.

In some infections, like those mentioned below, the fever may show regular periodicity.

1. Quotidian: There is a single, daily elevation eg, in flaciparum malaria.
2. Double Quotidian: There are two distinct daily peaks, eg, Kala azar
3. Tertian: Fever occurs on every third day, i.e, on alternate days, eg, Vivax malaria.
4. Quartan: The fever occurs every fourth day, (with two days intervals in between) eg, quartan malaria.
5. Relapsing fever: Short febrile periods occur between several days of normal temperature, eg, brucellosis, Hodgkin’s disease, rat bite fever.

To make out periodicity distinctly, it is necessary to record the temperature 4 hourly.

Chills or rigor may precede fever. Presence of chills and rigor suggests that the temperature is rising abruptly. Parasitic infections like malaria and filariasis, pyogenic infections like septicemia and endocarditis and virus diseases may give rise to chills and rigor. Many children develop convulsions during the rise of body temperature. Usually, febrile convulsions subside by the age of 5 years.

Alternation in mental state such as disorientation and delirium are common. Delirium may be defined as a toxic confusional state.

Crops of herpetic vesicles (herpes simplex) occur characteristically in conditions like pneumonia, malaria, meningococcal infections and rickettsia infections. Presence of herpes labialis is a point against typhoid fever. When the temperature rises by 1⁰C, the heart rate goes up by 18 to 20 counts per minute. There is also a slight rise in the respiratory rate. In some fevers, like pneumonia and rheumatic fever, the pulse is disproportionately high (rapid pulse fevers) and in others, like typhoid and meningitis, the pulse is disproportionately slow (slow pulse fevers).