Symptoms of Scarlet Fever

At first, the signs and symptoms of scarlet fever will basically be the same as those of strep throat—high fever and sore throat, among others. After a day or two, a red, body-wide rash and other signature symptoms, such as skin pigmentation and what's known as "strawberry tongue," will develop. Since scarlet fever is very contagious and uncomfortable, it's important to seek treatment as soon as you notice any indications of the infection. A course of antibiotics typically is prescribed. Without treatment, scarlet fever will get progressively worse and, may even lead to serious (though uncommon) complications.

Because scarlet fever is caused by the same organism that's responsible for strep throat, the group A streptococcus bacterium, both illnesses begin with a similar set of symptoms:

• Fever: Someone with scarlet fever will run a temperature that's at least 101 degrees, and 103 or 104 degrees isn't unusual. If the infection isn't treated with antibiotics, the fever can persist for as many as five to seven days.
• Sore Throat: The throat and tonsils of someone with scarlet fever will be red and swollen, and often coated with white pus. Glands in the neck also may be swollen and tender to the touch. It will hurt to swallow.
• Other: A child with scarlet fever likely will develop other symptoms typical of a bacterial infection. These may include nausea, vomiting, chills, headache, abdominal pain, and loss of appetite.

Scarlet Fever Rash

The main symptom that sets scarlet fever apart from strep throat is a rash.

The rash is made up of tiny red bumps and feels like sandpaper, especially on the arms and chest. When pressed on gently, the rash will blanch (turn white).

The rash is sometimes worse on the neck, elbow creases, armpits (axilla), and groin. It may last for as long as a week. Once it fades, the skin may peel for several weeks, especially on the face and the palms of the hands.

Other skin changes associated with scarlet fever include:

• Circumoral pallor: a pale area around the mouth
• Pastia's lines: dark, hyperpigmented areas in skin creases 
• "Strawberry tongue:" red, swollen bumps on the tongue with a white-ish coating

It's unusual for scarlet fever to have serious long-term side effects. When lingering health problems associated with scarlet fever do occur, it is usually because the group A strep bacteria have spread to parts of the body other than the throat.

This is most likely to happen if the infection isn't treated adequately: either no antibiotic is prescribed or an ineffective one is given. Bacteria also can spread if a person doesn't take the full course prescribed to them. Often a secondary group A strep infection will occur in a part of the body that's near the throat, such as the sinuses, tonsils, and ears. Sometimes a skin infection will develop from a strep infection.

Rheumatic fever is an inflammatory disease that can affect certain tissues and organs in the body. It isn't clear how a group A strep infection of the throat such as scarlet fever can play a role in rheumatic fever. A likely explanation is the strep bacterium contains a protein that's much like a protein in tissues of the heart, joints, skin, and brain, prompting the immune system to treat these structures as if they were infectious agents.

The inflammation that results can have serious, permanent effects on the heart, including damaged heart valves and heart failure. Rheumatic fever is most likely to develop in children between 6 and 16, but it's rare in the United States and other developed countries.

Like a rheumatic fever,​ post-streptococcal glomerulonephritis (PSGN) is an inflammatory disease that can develop after a group A strep infection such as scarlet fever. It affects the kidneys and causes symptoms such as dark, reddish-brown urine; edema (swelling) of the face, hands, and feet; decreased urine output; and fatigue (due to low iron levels). 

SGN can develop one to two weeks after infection with scarlet fever if the illness is not properly treated. And like most potential complications of group A strep infection, although kids are most susceptible, PSGN is rare.  

If you notice a rash that's accompanied by fever or throat discomfort, it's important to speak to your doctor or pediatrician, especially if you are aware of exposure to strep. Though scarlet fever is not as common as it once was, don't assume that symptoms could be the result of something else. Get an early, proper evaluation so treatment, if needed, can start as soon as possible.