Cellulitis appears as an expanding area of red, swollen, warm skin that feels tender or painful to the touch. The redness doesn’t have a sharp edge. Instead, it fades gradually into the surrounding normal skin, giving it a blurred, spreading look. It almost always affects just one side of the body, most commonly a leg, and it develops quickly over hours to days rather than weeks.
Color, Texture, and Borders
On lighter skin, cellulitis typically looks bright red. On darker skin tones, it can appear purple, deeper brown, or slightly darker than your usual skin color, sometimes resembling a flat rash. Regardless of skin tone, the area feels noticeably warmer than the skin around it.
The texture of the swollen skin often resembles the dimpled surface of an orange peel. This pitted look happens because the infection causes fluid to build up in the deeper layers of skin, pulling at the points where tissue is anchored underneath. The swelling can range from mild puffiness to dramatic enough that the skin looks stretched and shiny. Pressing on it may leave a temporary dent.
One of the most distinctive visual features of cellulitis is its borders. Unlike a well-defined rash with a clear outline, cellulitis has smooth, blurred edges that blend into normal skin. If you see a raised, sharply outlined area of redness instead, that’s more consistent with erysipelas, a related but more superficial infection that affects the upper layers of skin.
How It Feels Beyond What You See
The affected area is painful, not just tender. Many people describe it as a deep, aching soreness that gets worse when you press on it or move the limb. The warmth radiating from the skin is often obvious even without touching it. In moderate to severe cases, you may also develop a fever, chills, or a general feeling of being unwell. Nearby lymph nodes can become swollen and sore. These whole-body symptoms are common with cellulitis and help distinguish it from skin conditions that only cause surface-level irritation.
What Spreading Looks Like
Cellulitis doesn’t stay still. The redness actively expands outward, sometimes noticeably within hours. Doctors often draw a line along the edge of the redness with a pen so you can track whether it’s growing or shrinking after treatment starts. Once antibiotics are working, about 55% of cases stop spreading within the first day. By the second day of treatment, roughly 90% of cases show both a halt in spreading and visible improvement in redness and swelling. By day three, nearly all cases have turned the corner.
If the redness is growing rapidly or you notice red streaks extending away from the infected area toward your torso, that’s a sign the infection has reached your lymphatic system. These streaks can appear as thin red lines traveling up your arm or leg. This type of spread, called lymphangitis, moves fast. Within 24 hours it can involve multiple areas and, if untreated, can reach the bloodstream. Red streaks warrant immediate medical attention.
What Cellulitis Doesn’t Look Like
Cellulitis is commonly confused with other conditions, especially on the lower legs. Knowing what sets it apart can save you an unnecessary panic or, just as importantly, help you recognize when something really is cellulitis.
- Stasis dermatitis affects both legs, not just one. It develops slowly over months or years and involves brownish discoloration, flaky or peeling skin, and pitting swelling. The legs are generally not tender. Cellulitis, by contrast, is almost always one-sided, develops over days, and hurts.
- Lipodermatosclerosis creates a distinctive shape where the lower leg narrows sharply between the calf and ankle, sometimes described as looking like an inverted champagne bottle. The skin feels hard and bound down rather than soft and swollen. It’s often brown or bronze from iron deposits in the tissue and has been present for years.
- Lymphedema causes persistent swelling in one limb, but the skin tends to thicken over time and may develop a warty or rough texture. The swelling doesn’t leave a dent when you press on it, unlike the puffy, pitting swelling of cellulitis.
A key rule of thumb: cellulitis is rarely bilateral. If both of your legs look the same, the cause is almost certainly something else. Cellulitis is also acute. If the skin changes have been building for weeks or months without fever or worsening pain, a chronic condition is far more likely.
Where It Shows Up Most Often
The lower legs are by far the most common location, but cellulitis can develop anywhere bacteria enter the skin. That includes areas around surgical wounds, insect bites, cuts, cracked skin between the toes (from athlete’s foot), or eczema patches. On the face, it tends to appear on one cheek or around one eye. The pattern is always the same: a warm, painful, expanding patch of discoloration with blurred edges, centered around wherever the bacteria got in.
In some cases, blisters filled with clear or slightly cloudy fluid develop on the surface of the infected skin. This tends to happen when the swelling is severe enough to separate the upper skin layers. The presence of blisters, rapidly expanding redness, or darkening skin that turns dusky or purple at the center can indicate a deeper or more aggressive infection.