Systemic Lupus Erythematosus (lupus) is a chronic autoimmune condition where the body’s immune system mistakenly attacks its own tissues and organs. Influenza (the flu) is a seasonal respiratory illness caused by a virus, causing symptoms like fever, body aches, and cough. For individuals managing lupus, contracting the flu poses a significantly greater threat compared to the general population. This combination creates a dangerous scenario requiring immediate attention and specialized care.
Why Lupus Increases Risk of Severe Flu
The heightened danger of influenza for a person with lupus stems from two primary biological factors that compromise the body’s defenses. First, the condition itself causes immune system dysfunction, which limits the body’s ability to mount a strong defense against external invaders like the influenza virus. This makes it harder for the system to clear the infection efficiently.
Many medications used to manage lupus, such as corticosteroids and other immunosuppressants, further dampen the immune response. While these drugs control the autoimmune disease, they simultaneously reduce the body’s capacity to fight off the flu virus effectively, leading to a prolonged or more severe infection.
Second, lupus is characterized by chronic inflammation throughout the body. The flu acts as a massive inflammatory trigger that can overwhelm this already sensitized system. The viral infection introduces a large-scale inflammatory signal, creating a systemic burden the body struggles to manage. This intense inflammatory response increases the likelihood of complications and the overall severity of the illness.
Recognizing Specific Complications and Lupus Flares
When a person with lupus contracts the flu, they face a higher risk of developing severe complications requiring hospitalization. The weakened immune response frequently allows secondary bacterial infections, most commonly pneumonia and bronchitis. Individuals with lupus have a risk of invasive pneumococcal infection that is approximately 13 times higher than the general population.
Beyond typical flu complications, the viral stress can activate a systemic lupus flare. A flare is a period of increased disease activity where existing lupus symptoms worsen or new ones appear, such as severe joint pain, rash, or profound fatigue. Studies show a significant association between influenza infection and lupus flares resulting in hospitalization.
It is important to distinguish between the symptoms of the flu and a true lupus flare, though they often occur simultaneously. A flu-induced complication is typically an infection like pneumonia, while a flare represents the autoimmune disease becoming more active and potentially causing damage to major organs like the kidneys or heart. Since symptoms can overlap, any sign of illness must be treated urgently to address both the infection and the potential autoimmune activation.
Essential Steps for Immediate Medical Care
Immediate action is paramount for a person with lupus at the first sign of flu-like symptoms, including fever, body aches, or a sore throat. Any fever of 100°F (37.8°C) or higher should be considered a medical warning sign requiring urgent contact with a healthcare provider, as it signals a dangerous infection or a disease flare.
Antiviral medication is a cornerstone of acute treatment and must be started without delay. Antiviral drugs, such as oseltamivir, inhibit the influenza virus from replicating, but they are most effective when treatment begins within 48 hours of symptom onset. Starting treatment quickly lessens the severity and duration of the illness, which is important for immunosuppressed patients to prevent severe complications.
The healthcare provider will determine the appropriate antiviral regimen and may need to adjust the patient’s current lupus medications. Patients should monitor for severe warning signs, such as difficulty breathing, chest pain, confusion, or bluish discoloration of the lips or face. These symptoms indicate a medical emergency and necessitate immediate care.
Prevention and Preparedness
The most effective strategy for managing flu risk in lupus patients is proactive prevention, beginning with the annual influenza vaccination. The inactivated flu shot is recommended for all lupus patients and their household contacts, as it is safe and does not increase the risk of a disease flare. However, the nasal spray vaccine, which contains a live attenuated virus, is not recommended for individuals taking immunosuppressive medications.
In addition to the flu vaccine, the pneumococcal vaccine is advised to guard against the most common form of secondary bacterial infection. This typically involves a series of shots, such as PCV13 followed by PPSV23, which protects against the bacteria that cause pneumonia and other serious infections.
Before flu season, patients should establish a clear action plan with their rheumatologist. This plan should include knowing which physician to call first, having a low threshold for seeking medical attention, and understanding the process for obtaining an antiviral prescription immediately upon symptom onset. Proactive planning ensures a swift response when managing a viral infection alongside an autoimmune disease.