Scarlet fever produces a distinctive red rash with a sandpaper-like texture that typically starts on the trunk and spreads outward to the arms and legs. The rash is often easier to feel than to see, especially in the early stages. Along with the rash, scarlet fever causes a set of visible changes to the tongue, face, and skin folds that make it one of the more recognizable childhood illnesses.
The Sandpaper Rash
The hallmark of scarlet fever is a rash that feels rough and gritty, like running your hand over fine sandpaper. It usually appears one to two days after the fever and sore throat begin. The rash starts on the chest and stomach, then quickly spreads outward to the neck, arms, and legs. Up close, it looks like tiny raised bumps packed closely together over flushed skin.
On lighter skin, the rash appears red or pink, sometimes looking like a sunburn with goosebumps. On darker skin tones, the color change can be subtle or hard to see at all. In those cases, the sandpaper texture is the more reliable sign. Running your fingers across the skin will reveal the roughness even when the redness isn’t obvious.
The rash typically lasts about a week. As it fades, the skin often begins to peel, particularly on the fingertips, toes, and groin. This peeling can continue for several weeks and is a normal part of recovery, not a sign that the infection is worsening.
What Happens to the Tongue
Scarlet fever causes a two-stage change in the tongue that’s unlike most other infections. Early in the illness, the tongue develops a whitish coating with red, swollen bumps poking through. This is sometimes called a “white strawberry tongue.” After a few days, the white coating peels away, leaving the tongue bright red and bumpy, resembling the surface of a ripe strawberry. This “red strawberry tongue” is one of the most distinctive visual markers of scarlet fever.
Facial Flushing and Skin Fold Lines
Children with scarlet fever often develop flushed, rosy cheeks while the area immediately around the mouth stays noticeably pale. This contrast between bright red cheeks and a pale ring around the lips is a classic visual clue.
Another telltale sign appears in the body’s natural skin folds. The creases of the elbows, armpits, groin, and behind the knees can develop deep red or darkened lines where the rash concentrates. These lines, called Pastia’s lines, occur because the tiny bumps of the rash pack more densely in warm, folded areas of skin. They sometimes persist even after the rest of the rash has faded.
What Causes the Rash
Scarlet fever is caused by group A streptococcus, the same bacteria behind strep throat. What sets scarlet fever apart is that the specific strain produces toxins that trigger the skin reaction. There are three types of these toxins, and strains that produce two or three of them tend to cause a more intense rash. Not everyone who gets strep throat develops scarlet fever. It only happens when the bacteria release these particular toxins and the person hasn’t built immunity to them, which is why it’s most common in children between 5 and 15.
How It Differs From Similar Rashes
Several childhood illnesses can cause a red rash and fever, so it helps to know what sets scarlet fever apart. The sandpaper texture is the biggest distinguishing feature. Measles produces a rash that’s flat or slightly raised but smooth, and it typically starts on the face before moving downward. Scarlet fever’s rash starts on the trunk and feels rough to the touch.
Kawasaki disease can look similar to scarlet fever in its early stages, with fever, a rash, and a strawberry tongue. The key difference is timing: Kawasaki disease involves a fever lasting five days or longer, often spiking above 102°F and not responding well to fever reducers. Kawasaki disease also causes red, cracked lips, swollen hands and feet, and red eyes, features that aren’t part of scarlet fever. If a child’s fever persists beyond a few days and the rash doesn’t follow the sandpaper pattern, those are reasons to consider other diagnoses.
The Full Sequence of Symptoms
Scarlet fever doesn’t start with the rash. It begins like strep throat: sudden fever, sore throat, and sometimes headache or nausea. The rash follows within a day or two. Here’s the general visual timeline:
- Day 1: Fever, red and sore throat, possibly swollen glands in the neck. The tongue may start to develop a white coating.
- Days 2 to 3: The sandpaper rash appears on the trunk and spreads. Cheeks flush while the mouth area stays pale. Skin fold lines may become visible.
- Days 3 to 5: The white tongue coating peels, revealing the red strawberry tongue underneath. The rash reaches its peak intensity.
- Days 7 to 10: The rash fades, and the skin begins to peel in sheets or flakes, especially on the hands and feet.
With antibiotic treatment, the fever typically breaks within a day or two, and the rash begins to improve shortly after. The peeling phase is the last visual sign to resolve and can take two to three weeks to fully clear. The skin underneath is healthy and undamaged.