Low grade pyrexia: is it chronic fatigue syndrome?

Area of Science:

• Internal Medicine
• Clinical Immunology
• Infectious Diseases

Background:

• Prolonged low-grade pyrexia is a challenging clinical presentation.
• Patients often exhibit non-specific symptoms and few physical signs.
• Extensive investigations frequently yield unrewarding results.

Purpose of the Study:

• To investigate the natural history and potential diagnosis of prolonged low-grade pyrexia.
• To identify characteristics and outcomes of patients with unexplained fever.
• To explore the relationship between this syndrome and chronic fatigue syndrome.

Main Methods:

• A cohort of 87 consecutive patients with prolonged low-grade pyrexia (99-101°F) was followed.
• Data collected included demographics, symptom onset, clinical findings, and extensive investigations.
• Follow-up duration averaged 2.9 years (range 2-5 years).

Main Results:

• The majority of patients (75.8%) were female, with a mean age of 37.55 years.
• Common symptoms included fatigue, arthralgias, myalgias, and chilly sensations.
• Physical examination revealed minimal findings; investigations for infection, autoimmune disorders, and malignancy were negative.
• Spontaneous resolution occurred in 13 patients within 1 year, 38 by 2 years, and 45 by 3 years.

Conclusions:

• Prolonged low-grade pyrexia, characterized by non-specific symptoms and negative investigations, often resolves spontaneously over time.
• The clinical presentation and natural history suggest this syndrome may represent a variant of chronic fatigue syndrome.
• Further research is warranted to fully understand the etiology and management of this condition.