Impetigo starts as small red bumps that quickly turn into pus-filled blisters, which burst and dry into a distinctive golden, honey-colored crust. This crust is the hallmark sign, and it’s often how people first realize they’re dealing with impetigo rather than another skin condition. The sores most commonly appear on the face (especially around the nose and mouth) and on the arms and legs, though they can show up anywhere.
How Non-Bullous Impetigo Develops
Non-bullous impetigo is the most common type, and it follows a predictable visual pattern. It begins as a small red, flat spot on the skin that quickly evolves into a tiny blister or pus-filled bump. Within a day or two, that blister ruptures and leaks a clear or slightly yellowish fluid. As the fluid dries, it forms the thick, stuck-on crust that looks golden or honey-colored. This crust is the single most recognizable feature of impetigo.
The surrounding skin usually shows little to no redness, which can make the crusty sore look oddly isolated. On darker skin tones, the initial red flat spot can be harder to see, so the first obvious sign may be the crusting stage itself. Sores tend to cluster in groups and can spread to nearby skin as the fluid from broken blisters touches healthy areas.
Bullous Impetigo: Larger Blisters, Different Location
Bullous impetigo looks noticeably different. Instead of small blisters that rupture quickly, it produces larger, fluid-filled blisters that stay intact longer before breaking open. These blisters contain a clear or cloudy fluid and appear most often on the trunk, arms, and legs rather than the face. This type occurs primarily in infants and children younger than 2 years old. When the blisters finally burst, they leave behind a raw, red area that may develop a thinner crust than the classic honey-colored type.
Ecthyma: The Deeper Form
Ecthyma is sometimes called a deeper form of impetigo because it extends below the skin’s surface layer into the tissue underneath. It starts the same way, as a small pus-filled bump, but instead of staying shallow, the lesion erodes into an ulcer. The result is a punched-out sore covered by a thick, hard crust with reddened edges. Ecthyma sores are more painful and slower to heal than standard impetigo, and they’re more likely to leave a scar.
Where Sores Typically Appear
Impetigo favors exposed skin. The face is the most common location, particularly around the nose and mouth, because bacteria enter easily through small cracks or irritation in that area. The arms and legs are the next most frequent sites. In young children, sores can also develop around the diaper area. Any break in the skin, whether from a scrape, insect bite, or patch of eczema, gives bacteria an entry point, so impetigo sores sometimes ring an existing wound.
How It Differs From Cold Sores
Because impetigo often appears around the mouth, it’s easy to confuse with cold sores. A few visual differences help tell them apart. Cold sores typically form as a tight cluster of small blisters on or right at the edge of the lips, and people often feel tingling or numbness in that spot before any blisters show up. Impetigo produces no warning sensations before sores appear. The sores themselves are weepy and spread more freely across the skin rather than staying in one tight cluster, and they dry into that characteristic honey-colored crust. Cold sore crusts tend to be darker and scab-like. Impetigo is also more likely to show up on areas beyond the mouth, like the arms, legs, and nose.
The Stages From Start to Finish
Knowing the progression helps you identify impetigo at each stage:
- Stage 1: A small, flat red spot appears on the skin. It may look like a minor irritation or bug bite.
- Stage 2: The spot develops into a small blister or pus-filled bump within a day or so.
- Stage 3: The blister ruptures and leaks clear fluid that is highly contagious.
- Stage 4: The fluid dries into a thick, golden or honey-colored crust that sticks firmly to the skin.
- Stage 5: With treatment, the crust gradually loosens and the skin underneath heals. New sores may appear nearby if the infection spreads before treatment begins.
Impetigo is diagnosed visually. A healthcare provider can typically identify it on sight based on the appearance and location of the sores, without needing lab tests.
What It Looks Like on Different Skin Tones
Most descriptions of impetigo reference redness around the sores, but that redness can be difficult or impossible to see on medium to dark skin tones. The early flat red spot that marks the beginning of non-bullous impetigo may blend into the surrounding skin entirely. On darker skin, the most reliable visual clue is the crust itself, its golden or yellowish color, along with any weeping or oozing from the sore. If you’re checking a child’s skin and don’t see obvious redness, look instead for raised bumps, fluid leaking from the skin, or yellowish crusting.
Signs It May Be Getting Worse
Standard impetigo stays in the upper layers of skin and heals without lasting marks. But if the infection spreads deeper, the area around the sore may become increasingly red, swollen, warm, and painful. Spreading redness that extends well beyond the sore’s edges can signal cellulitis, a deeper skin infection that needs prompt treatment. Fever, rapidly expanding sores, or sores that aren’t improving after several days of treatment are all signs the infection may be progressing.
Scarring and Skin Color Changes
Non-bullous impetigo that stays shallow typically heals without scarring. However, the skin where sores healed may temporarily look darker or lighter than the surrounding area. These color changes, known as post-inflammatory pigmentation, range from light brown to near-black and are more noticeable on darker skin tones. They fade over weeks to months in most cases. Ecthyma, because it damages deeper skin layers, is more likely to leave permanent scars or lasting lighter patches where the ulcer healed.