Jeffrey S. Imel WEMT, NREMT – School of First Aid


Local infections result from a complex interaction between invading pathogens and the host’s immune response, leading to symptoms like swelling, heat, pain, redness, and pus formation, which can progress to abscesses or chronic conditions without effective immune clearance. Treatment focuses on wound care and infection control through cleaning, applying a hot, moist, salty gauze, covering the wound, elevation, and monitoring for systemic infection, alongside maintaining hydration, nutrition, and hand hygiene to support healing and prevent further infection spread.

Pathophysiology of Local Infections

The pathophysiology of a local infection involves a complex interaction between the invading pathogen (such as bacteria, viruses, fungi, or parasites) and the host’s immune response. The classic signs of infection at a local site—swelling (tumor), heat (calor), pain (dolor), redness (rubor), and pus formation (sometimes described as loss of function or functio laesa in broader inflammatory contexts)—can be explained through the following mechanisms:

Resolution or Chronic Infection: Ideally, the immune response successfully eliminates the pathogen, and the tissue begins to repair itself, returning to normal function. However, if the immune response is unable to clear the infection completely, it can become chronic, leading to sustained inflammation and potential tissue damage.

This dynamic and complex response to infection is a fundamental aspect of the body’s defense mechanism but can also contribute to the symptoms and tissue damage associated with infections. Understanding these processes is critical for developing effective treatments and interventions for infectious diseases.

Infection Identification and Treatment Workflow Diagram from Wilderness First Aid Made Easy 6th Edition

Treatment for a Local Infection

First aid treatments for a local infection, especially in austere environments where access to medical facilities and antibiotics may be limited, focus on basic principles of wound care and infection control. These measures aim to prevent the spread of infection, support the body’s natural healing processes, and mitigate the risk of complications. One such treatment involves the use of a hot, moist, salty gauze pad. Below, we’ll discuss this and other first aid treatments for local infections:

  • Apply a Hot, Moist, Salty Gauze Pad: The application of a hot, moist, salty gauze pad can be particularly beneficial for a localized infection for several reasons:
    • Heat: Applying heat increases blood flow to the area (vasodilation), which can help bring more white blood cells to fight the infection and promote faster healing. Heat also helps in reducing pain. Applying warm compresses can help draw pus to the surface and promote natural drainage.
    • Moisture: Keeping the wound environment moist can facilitate the healing process by providing an optimal environment for cell migration and wound repair. It also helps in dissolving and removing dead tissue.
    • Salt (Saline Solution): A saline solution (salt water) acts as an osmotic agent, helping to draw out fluid from the tissues and the pathogens along with it, potentially reducing swelling and promoting the removal of bacteria. Salt also has mild antibacterial properties, which can help control the microbial load in the wound.

In austere environments, these first aid treatments can be life-saving measures that utilize readily available materials to manage infections until professional medical care can be accessed. However, it’s important to note that while these methods can be effective in managing minor infections and promoting healing, they are not substitutes for professional medical treatment, especially in cases of severe infection or when there’s a risk of complications.