Prep School Daily: Fever Patterns That Aid Diagnosis in a Resource-Poor Situation

Last month I listened to a Patriot Nurse Youtube on the 5 critical first aid skills we all need to have.[1] And the last thing she covered was fever management. I wasn’t entirely sure I’d written on that topic, and a quick check of the blog revealed the omission. I thought it important to discuss and had previously noted the wisdom of acquiring a glass, non-digital, thermometer. We older folks all used them as kids, but most of our children have only used digital thermometers. I don’t think mine have ever seen me shake down a glass thermometer. They certainly have no clue how long to hold them under the tongue. So that’s what that article was for.

In researching that article, I came across a few pages in Where There Is No Doctor on the different fever patterns. And I have included info on the distinct fever patterns found with some of the illnesses that have been covered on the blog. However, I was pretty sure I hadn’t seen any mention of these patterns in any of my other off-grid medical texts.

Sure enough, nobody else addressed it. And why is it important?

Thought you’d never ask.

As you recall from the previous fever article, most fevers are associated with respiratory infections. However, there are several serious infections that are accompanied by a fever with a specific pattern, some of which resemble respiratory infections (at least in the beginning), and which are not respiratory infections. Sneaky little buggers.

If we are recording the temperature at least a few times per day, even plotting it on a graph, we may see a pattern develop. In a world with limited physician and/or laboratory access, these distinct fever patterns may reveal it’s not a respiratory illness at all. Rather, the infection is something more sinister.

Full articles have been posted on many of these illnesses (links below). Here we are briefly describing the symptoms and the fever pattern.

Acute fever (less than 7 days long)

Malaria
Viral upper respiratory tract infections

Sub-acute fever (less than 14 days long)

Typhoid
Intra-abdominal abscess

Chronic fever (more than 14 days long)

Tuberculosis
HIV
Cancer
Connective tissue disease
Any cause of acute fever if untreated

Normal and Febrile Body Temperature Ranges (Rectal Temperature)
Body Temperature	Fahrenheit (°F)	Celsius (°C)
Normal	98.6-100.4°	37-38°
Mild fever	100.5-102.2°	38.1-39°
Moderate fever	102.3-104°	39.1-40°
High fever	104.1-106°	40.1-41.1°
Hyperpyrexia[2]	>106°	>41.1°

Does the height of the body temperature indicate severity of the illness?

Researchers indicate that the height of the temperature may aid diagnosis. Studies correlate high fevers in infants to serious bacterial infection, noting that hyperpyrexia (extremely high fever) is rare in infants less than 3 months of age, and that one-third of infants in this group who presented with a temperature over 40°C also had a serious bacterial infection.[3]

Researchers also found that 20% children with hyperpyrexia also had a serious bacterial infection and recommended antibiotic therapy in the absence of a confirmed viral illness.[4]

In general, however, the height of the fever only occasionally correlates with the severity of the illness.

Hyperpyrexia and severe illness

Shigellosis
Dengue
Acute falciparum malaria

The overall clinical state of the patient (check those vital signs!) is usually a better indicator of serious illness than the height of the fever.[5]

Five major fever patterns

A continuous fever does not fluctuate more than 1.5°F (1°C) during a 24-hour period and never touches normal. This is seen with the following illnesses:

Pneumonia, lobar or gram-negative
Typhoid
Acute bacterial meningitis
Urinary tract infection

A fever with a slow, stepwise temperature increase and high plateau suggests typhoid fever. This is only infrequently observed because most patients self-medicate with antibiotics and fever-reducing medications before seeing a doctor. If this fever occurs with relative bradycardia, it points to the following possible illnesses:

Untreated typhoid
Leishmaniasis
Brucellosis
Legionnaire’s disease
Psittacosis
Yellow fever[6]

An intermittent fever pattern, where the fever occurs for several hours each day, is observed with the following illnesses:

Malaria (periodicity of fever varies from every 24 to 72 hours, depending on the species)
Tuberculosis
Schistosomiasis
Pyogenic infections (pus-producing infections, most commonly due to Streptococcus and Staphylococcus bacteria)
Lymphomas (low fever lasts 3-10 days followed by afebrile period of 3-10 days)[7]
Septicemia
Leptospirosis
Borrelia infections, including Lyme disease
Kala-azar, visceral leishmaniasis

Remittent fever includes daily temperature fluctuations of more than 2°C (about 3.5°F), but which never touch normal.[8] Illnesses include:

Rickettsiae infections (most commonly tick-borne, but fleas and lice are also vectors)
Brucellosis
Infective endocarditis

Relapsing fevers are recurring fevers separated by periods of low- or no fever. These occur with

Malaria
Lymphoma
Borrelia
Cyclic neutropenia
Rat-bite fever

Night-sweat fevers are seen with

Tuberculosis
Brucellosis
Liver or lung abscess
Sub-acute infective endocarditis
Lymphomas

FEVER PATTERN DESCRIPTIONS FOR SPECIFIC DISEASES

Brucellosis. Fever and sweating most frequently occur at night, with the fever disappearing for a few days and then returning. This may continue for months or years.[9]
Childbirth fever. A slight fever begins one or more days after giving birth, and then the fever increases later. [10]
Hepatitis. Mild fever, which decreases when the eyes turn yellow. [11]
Malaria. Fever comes and goes for a few days, accompanied by shivering and chills as the body temperature rises and sweats as it falls. Then the patient is feverish for a few hours every 2-3 days, feeling more or less well at other times. [12]
Pneumonia. Temperature rises quickly and remains high with a bacterial infection, gradually decreasing with a viral infection. [13]
Rheumatic fever. Sudden fever with a sore throat is followed by another fever 10-15 days later.[14]
Tick-borne relapsing fever. Fever for 3 days, following by a 7-day break, and then another 3 days of fever and a 7-day break, and it keeps going.[15]
Typhoid. The temperature rises a little more each day.[16]
Typhus. Similar to typhoid.[17]

So why are these fever patterns important? What is their significance?

After all, as noted above, many of these fever patterns aren’t seen in clinical practice. Today. And that is because people often start self-medicating before seeing a doctor. That, of course, messes with the pattern. Tomorrow, the story may be different.

And as you use these patterns to help identify what’s troubling a family member, keep in mind that elderly, severely malnourished, and immunocompromised people sometimes don’t develop a fever at all. Also, concurrent infection with another illness may alter fever patterns.[18]

But when a pattern can be identified, it may offer useful clues for diagnosing diseases, including ruling out other diseases. And this will be particularly important when we find ourselves with few resources.

Links to related posts:

Tick-borne relapsing fever

Typhoid

Typhus

Glass thermometers

[1] https://www.youtube.com/watch?v=ab67H-JshWo

[2] With severe malaria, hyperpyrexia is considered a rectal temperature above 40°C.