EpistemisIdiopathic or persistent low-grade fever
Specialty: General.
Why it occurs
- Autonomic dysregulation of the hypothalamic thermoregulatory center (psychogenic or essential low-grade fever, common in situations of chronic stress or anxiety disorders)
- Bacterial or viral infections of low degree of activity (atypical tuberculosis, subclinical chronic urinary tract infections, or subacute endocarditis)
- Autoimmune disorders with an indolent course (initial systemic lupus erythematosus, Behçet's disease or small vessel vasculitis)
- Mild thyroid dysfunction or subclinical hyperthyroidism (which increases the basal metabolic rate and cellular thermogenesis without causing thyroid storm)
- Chronic consumption of certain drugs or stimulant substances (sympathomimetics, amphetamines, or withdrawal from depressant substances).
Initial workup
Regulated thermometry every 4 hours noted by the patient in different conditions, complete blood count with peripheral blood smear, acute phase reactants (CRP, ESR), TSH, free T4, general urine examination, and chest x-ray.
red flags
Transformation of low-grade fever into intermittent high fever, weight loss greater than 5% of body weight without apparent cause, profuse night sweats, bone pain that interrupts sleep, or lymphadenopathy with a stony consistency in any territory.
Standard management
- Paracetamol — 500 mg orally only in low-grade fever peaks that generate headache or intolerable discomfort, avoiding daily abuse
- Diazepam — 2 mg orally at night if a component of anxiety or psychogenic low-grade fever is suspected, to evaluate response by central modulation
- Passive physical cooling measures (light clothing, adequate ventilation of the environment).
Educational guidance for study. It is NOT a prescription recommendation. The actual choice depends on the cause, the patient, and current guidelines.
- Area
- General
- Listed causes
- 5
- Treatment options
- 3