Cotton fever

Overview

Cotton fever is an acute, self-limited febrile illness that most commonly occurs in intravenous (IV) drug users who inject drugs using cotton filters. It is characterized by the sudden onset of fever, chills, and flu-like symptoms shortly after injection. While the condition mimics serious infections like sepsis, cotton fever is typically benign and resolves within 12 to 24 hours without specific treatment. Due to its rapid onset and overlap with more severe illnesses, cotton fever can be alarming and often leads to emergency medical visits.

Causes

The primary cause of cotton fever is the use of cotton balls or other fibrous materials to filter intravenous drugs before injection. Several theories explain the origin:

• Endotoxin theory: The most accepted theory suggests that endotoxins (bacterial toxins) from Enterobacter agglomerans, a bacterium commonly found in cotton plants, are introduced into the bloodstream during injection.

• Particulate theory: Small fibers or particles from cotton may provoke an immune response or localized inflammation.

• Contamination theory: Reused or improperly stored filters may harbor bacteria or pyrogens that trigger fever and systemic symptoms.

The reaction is not due to an actual infection in most cases, but the body reacts as though exposed to a bacterial invader.

Symptoms

Symptoms of cotton fever typically begin within 30 minutes to 2 hours after IV drug injection and may include:

• Fever: Often high, with a sudden onset

• Chills and rigors: Intense shivering is common

• Muscle and joint aches: Generalized body discomfort

• Headache

• Nausea or vomiting

• Rapid heartbeat (tachycardia)

• Feeling unwell or weak: General malaise and fatigue

Symptoms typically peak quickly and resolve within 6 to 24 hours. If symptoms persist longer or worsen, it may indicate a more serious infection.

Diagnosis

Diagnosis of cotton fever is largely clinical and based on patient history, particularly recent IV drug use and the method of filtration. Diagnostic steps include:

• Medical history: Identification of recent drug injection using cotton or other non-sterile filters

• Physical examination: To rule out signs of more serious infection (e.g., abscesses, endocarditis)

• Blood tests: Often normal or mildly elevated white blood cell count; used to rule out sepsis

• Blood cultures: Usually negative in cotton fever but obtained if infection is suspected

• Urine or wound cultures: Performed if clinical suspicion exists for alternate diagnoses

Because the symptoms mimic sepsis, many patients undergo extensive testing to ensure more dangerous infections are not present.

Treatment

Cotton fever usually resolves on its own without specific treatment. Management is supportive and may include:

• Hydration: Oral or intravenous fluids to prevent dehydration

• Antipyretics: Medications such as acetaminophen or ibuprofen to reduce fever and discomfort

• Rest: Allowing the body to recover naturally

• Antibiotics: Not typically needed unless a bacterial infection is suspected or confirmed

Hospitalization may be necessary if symptoms are severe, prolonged, or if there is uncertainty about the diagnosis.

Prognosis

The prognosis for cotton fever is excellent in most cases. Symptoms usually resolve within 24 hours without long-term complications. However, repeated episodes can occur if IV drug use with cotton filtration continues. While the condition itself is not dangerous, it indicates unsafe injection practices that carry serious risks, including HIV, hepatitis, and bacterial infections. Education, harm-reduction strategies, and referral to addiction treatment services are essential components of long-term care.