Cellulitis is a common bacterial skin infection that affects the deeper layers of the skin and the tissue directly beneath it. It can occur anywhere on the body, though it frequently appears on the lower legs, face, and arms. Early recognition of cellulitis is important for effective treatment, as it can spread quickly if left unaddressed. While several types of bacteria can cause this infection, Staphylococcus aureus (Staph) is a very common culprit.
The Distinct Appearance of Cellulitis
Cellulitis presents with several observable characteristics. The affected skin often displays redness, known as erythema, which can range from a bright red to a dusky red hue, appearing inflamed. This redness may be less obvious on darker skin tones, appearing more purple or dark brown. Along with the discoloration, swelling, or edema, is prominent, making the area look puffy, raised, and sometimes shiny or stretched due to fluid accumulation.
The infected area will also feel noticeably warm or hot to the touch when compared to the surrounding skin. Unlike some rashes that have clear boundaries, cellulitis often features indistinct or poorly defined borders, indicating the infection is spreading. However, in some cases, particularly a superficial form called erysipelas, the borders can be sharply demarcated.
The skin’s texture can change, sometimes showing dimpling, which might resemble an orange peel. In more severe instances, fluid-filled blisters (bullae) or pus-filled bumps (pustules) may form on the skin’s surface.
Accompanying Symptoms
Cellulitis often brings other symptoms beyond its visual presentation. The affected area commonly experiences pain and tenderness, feeling sore even without direct touch. This discomfort can be persistent and may intensify as the infection progresses.
Systemic symptoms, which indicate a more widespread infection, can also develop. These may include a fever, chills, and a general feeling of being unwell, often described as malaise or fatigue. Additionally, lymph nodes located near the infected area, such as those in the groin for leg cellulitis, can become swollen and tender.
How Cellulitis Develops and Spreads
Cellulitis typically begins when bacteria, often Staphylococcus aureus, enter the body through a break in the skin. This entry point can be a minor cut, a scrape, an insect bite, a surgical incision, or even skin conditions like athlete’s foot or dermatitis that compromise the skin barrier. Once inside, these bacteria multiply within the deep dermis and subcutaneous tissues, leading to infection.
The infection can progress rapidly, with the redness and swelling expanding over a matter of hours or days. In some cases, red streaks, known as lymphangitis, may become visible extending from the infected area towards the nearest lymph nodes. These streaks indicate that the bacteria are spreading through the lymphatic system, which is part of the body’s immune defense network.
When to Seek Urgent Medical Care
Prompt medical attention is crucial for cellulitis, especially if certain signs emerge. Rapid worsening of the redness, swelling, or pain indicates that the infection is advancing quickly and requires immediate assessment. Systemic signs, such as a high fever, severe chills, confusion, or dizziness, are also serious indicators that warrant urgent care.
Red streaks extending from the infected site suggest the infection is spreading, necessitating prompt medical intervention. If blisters, boils, or areas filled with pus develop on the skin, this can signal a more severe infection or complications. Additionally, if the affected limb experiences numbness, coldness, or weakness, it could indicate nerve involvement or compromised circulation.
Facial cellulitis, particularly around the eyes or nose, is considered particularly serious due to its proximity to the brain. Individuals with underlying conditions such as diabetes, a weakened immune system, or peripheral artery disease should also seek immediate care if they suspect cellulitis, as they are at higher risk for complications.