Staph infections on the skin typically appear as red, swollen, warm areas that may be filled with pus or topped with a crusty scab. The exact look depends on which type of staph infection you’re dealing with, and they range from superficial pimple-like bumps to deep, painful abscesses. Here’s how to recognize the most common forms.
General Signs on the Skin
Regardless of the specific type, most staph skin infections share a few visual features. The affected area is usually discolored compared to the surrounding skin. On lighter skin this looks red; on darker skin tones it may appear purplish or brown. The skin feels warm and firm to the touch, is painful or tender, and is often visibly swollen.
Pus is a hallmark. Staph infections frequently produce white or yellow drainage, either from an open sore or visible beneath the skin as a pocket of fluid. Some infections form blisters that rupture, leaving behind a raw, moist surface that can look like a burn. Others crust over with a yellowish scab. If the infected area is also itchy, peeling, or expanding outward, those are additional signs that staph bacteria are involved.
Folliculitis: Pimple-Like Bumps
The mildest form of staph skin infection is folliculitis, which targets hair follicles. It looks like a cluster of small pimples, each centered on a follicle. The bumps are pus-filled, and unlike regular acne, they tend to be noticeably itchy. Over time, they can break open and crust over into small sores. Folliculitis commonly shows up on the thighs, buttocks, back of the neck, or anywhere clothing creates friction against the skin.
Impetigo: Honey-Colored Crusts
Impetigo is extremely common in young children and has a distinctive appearance that’s hard to miss. It starts as red, itchy sores, usually around the nose and mouth. The sores break open and leak clear fluid or pus for a few days. Then a crusty, honey-colored scab forms over each sore. That golden-yellow crust is the signature visual marker of impetigo. The good news: it typically heals without leaving a scar.
Boils and Carbuncles: Deep Pus Pockets
Boils (also called furuncles) are deeper infections that form painful, red lumps under the skin. A boil starts out small but can grow to more than two inches across over several days as it fills with pus. The surrounding skin becomes swollen and reddish or purplish. Eventually, a yellow-white tip develops at the surface. When it ruptures, thick pus drains out, and the pain usually eases. Boils tend to appear in areas with friction and moisture: the armpits, groin, buttocks, and inner thighs.
A carbuncle is a cluster of boils that merge into a single, connected area of infection. Carbuncles are deeper and more severe than a lone boil, more likely to leave a scar, and often accompanied by fever and chills. They most commonly form on the back of the neck or shoulders.
Cellulitis: Spreading Redness Without a Head
Unlike boils and impetigo, cellulitis doesn’t produce a visible pus pocket or crusty sore at the surface. Instead, it infects the deeper layers of skin and looks like a spreading patch of redness, swelling, and warmth. The skin may feel tight or look dimpled, and blisters can develop in more severe cases. Cellulitis typically affects the lower legs but can appear anywhere. The key visual clue is that the redness expands outward over hours or days rather than staying in one spot.
MRSA: Starts Small, Escalates Fast
Antibiotic-resistant staph infections (MRSA) don’t have a unique look that sets them apart from other staph infections early on. They begin as small red bumps that resemble pimples or spider bites. The critical difference is speed: MRSA bumps can quickly turn into deep, painful abscesses within days. If a pimple-like bump rapidly grows, becomes increasingly painful, and develops a warm, swollen halo of redness, MRSA is a real possibility.
One common point of confusion is mistaking a staph infection for a spider bite. Staph infections are more likely to produce white or yellow pus, feel warm, and come with a fever. A venomous spider bite, by contrast, is more likely to form a purple or blue ulcer and develop blisters near the bite site.
Scalded Skin Syndrome in Children
Staphylococcal scalded skin syndrome is a serious reaction to toxins produced by staph bacteria, and it occurs almost exclusively in infants and young children. About 24 hours after initial symptoms like fussiness and fever, a widespread, painful rash appears across the child’s body, concentrating on the face, neck, armpits, shoulders, and groin. The skin develops deflated-looking blisters that hang downward, and even gentle pressure causes the upper layers of skin to peel away, revealing shiny, raw, moist patches that look like burns. It does not affect the palms, soles of the feet, or the inside of the mouth.
Signs the Infection Is Getting Worse
A staph infection that’s healing will gradually become less red, less swollen, and less painful. One that’s worsening does the opposite: the redness spreads, the swelling increases, and the pain intensifies. Fever, chills, or feeling generally unwell suggest the infection is moving beyond the skin.
The most important visual warning sign to watch for is red streaks extending outward from the infection site toward your armpit or groin. These streaks, which can be faint or obvious, indicate the infection has reached the lymphatic system and is spreading. A rapidly expanding rash, especially one accompanied by fever, also signals that the infection needs urgent medical attention.