Cellulitis is a common bacterial infection that affects the skin and the tissues lying just beneath it. It often appears on the legs, causing noticeable changes in skin appearance. Early recognition and timely medical attention are important to prevent the infection from becoming more severe.
Recognizable Signs of Cellulitis
Cellulitis on the legs typically presents with a rapidly expanding area of skin discoloration. This area often feels warm to the touch and appears swollen, accompanied by tenderness or pain when pressed. On lighter skin tones, discoloration usually appears as red or pink patches. On darker skin tones, it might look dark brown, gray, or purple, making it less obvious.
The affected skin may develop a taut, shiny, or stretched appearance, sometimes resembling an orange peel with small divots or pitting. Small fluid-filled blisters or pus-filled bumps can form on the discolored skin. Red streaks extending from the main infected area indicate the infection is spreading through the lymphatic vessels, a condition known as lymphangitis.
Differentiating Cellulitis from Other Skin Issues
Distinguishing cellulitis from other skin conditions on the legs is important because many conditions can present with similar symptoms. For instance, a common insect bite often results in localized redness and swelling, frequently with a central puncture mark, and typically features itchiness as a prominent symptom rather than significant pain or warmth. Cellulitis, however, usually lacks a distinct central bite mark and is characterized by spreading discoloration and pain.
Contact dermatitis, an inflammatory reaction to an irritant or allergen, can also cause red, swollen skin. But it is typically very itchy and often has clear borders or patterns that correspond to the area of contact. Unlike cellulitis, contact dermatitis usually does not cause systemic symptoms like fever or a general feeling of illness. Deep vein thrombosis (DVT), a blood clot in a deep vein, can cause leg swelling, pain, and sometimes discoloration. Yet, DVT typically lacks the intense warmth and distinct spreading redness characteristic of cellulitis. DVT often affects only one leg and may not present with the same skin surface changes as cellulitis.
Simple rashes or chronic conditions like stasis dermatitis can also cause redness and swelling on the legs. These are often bilateral, affecting both legs, and may be associated with long-standing venous insufficiency. Cellulitis is typically unilateral, meaning it affects only one leg. These differentiating factors, such as the presence of itchiness, clear borders, bilateral involvement, or the absence of warmth and spreading, help distinguish these conditions from cellulitis.
When to Seek Medical Attention
Prompt medical evaluation is important if you suspect cellulitis, as the infection can progress quickly. Seek medical attention if you notice rapidly spreading redness or discoloration, increasing pain, or if the affected area becomes numb or discolored. Other urgent signs include the development of a fever, chills, fatigue, or a general feeling of being unwell.
A healthcare professional will typically diagnose cellulitis based on a physical examination and your medical history. Early treatment with antibiotics is usually effective in preventing complications, which can include the spread of bacteria into the bloodstream, a potentially severe condition. If symptoms do not improve within 24 to 48 hours of starting antibiotics, or if they worsen, further medical assessment is necessary.