A common bacterial skin infection that affects the deeper layers of the skin and the underlying tissues.
Cellulitis is a frequently occurring bacterial infection that involves the deeper layers of the skin as well as the soft tissues beneath it. The condition often develops quickly and can become serious if not treated promptly. It most commonly affects the legs, but it can occur anywhere on the body where the skin barrier has been compromised.
What Is Cellulitis?
Cellulitis happens when harmful bacteria invade the skin and multiply within the tissue. The two organisms most often responsible are Streptococcus and Staphylococcus species. Once inside, these bacteria trigger inflammation, leading to redness, swelling, warmth, and discomfort in the affected area.
How Cellulitis Develops
The infection typically begins when bacteria enter through a weak point in the skin. Several scenarios can create this opening:
Bacterial Entry Through Damaged Skin
Breaks in the skin—such as cuts, scrapes, insect bites, burns, surgical wounds, or even cracked, dry skin—provide an entry point for bacteria. Even small or unnoticed injuries can lead to infection.
Problems With Lymphatic or Circulatory Drainage
An impaired lymphatic or venous system can reduce the body’s ability to remove excess fluid and fight infections. This can make it easier for bacteria to grow and spread.
Increased Susceptibility
Certain conditions raise the risk of developing cellulitis, including:
- Diabetes
- Weakened immune function
- Poor circulation
- Obesity
- Previous episodes of cellulitis
- Skin conditions that break down the barrier (e.g., eczema, athlete’s foot)
Signs and Symptoms
Cellulitis often appears suddenly and can worsen quickly. Common signs include:
- Redness that spreads outward from the initial site
- Warmth and a hot sensation in the affected area
- Swelling that may become pronounced
- Pain or tenderness, often increasing over time
- Fever or chills, especially in more advanced infections
- Blisters that may contain clear or cloudy fluid
- Tight, shiny skin as swelling increases
- Enlarged lymph nodes near the infected region
- Expanding rash or red streaks moving away from the wound
When to Seek Medical Care
Cellulitis requires prompt treatment because the infection can spread to the bloodstream or deeper tissues. Most cases are treated with antibiotics, chosen based on the suspected bacteria and severity. Supportive care—such as elevating the affected limb, applying warm compresses, and keeping wounds clean—can help reduce discomfort and promote healing.
It is essential to complete the full course of antibiotics as prescribed. Anyone who notices worsening redness, persistent fever, or spreading symptoms should seek medical attention immediately.
