In early 2018, 12-year-old Alyssa Lino Alcaraz passed away after her strep throat, which would go on to cause fatal complications, was allegedly initially misdiagnosed as the flu. Alcaraz's case makes it clear that it's important to know from the beginning how to tell the difference between strep throat and the flu virus; even in less extreme cases, knowing how to tell the difference between the two will help sufferers clarify symptoms, get more accurate treatment, and get back to full health faster.

Strep throat, or a streptococcal infection, is a bacterial infection that requires treatment with antibiotics, while the flu virus can't be targeted with antibiotics and is usually treated with antivirals or by supporting the body until the immune system fights the virus off.

"In general, people with strep throat will have fevers, no cough, swelling of the tonsils or white patches on their throat, and tender neck lymph nodes," Dr. Amir H. Barzin, DO, MS, director of the UNC Family Medicine Center, tells Bustle. "People with the flu can have the same symptoms, but can also experience body aches, headaches, stomach issues (likely nausea and vomiting) and extreme fatigue. Sometimes symptoms that one thinks are the flu could actually be strep throat and vice versa." Both strep throat and the flu are fairly contagious when somebody is experiencing symptoms (though less so when they're not), according to the Mayo Clinic.

White spots, red spots, or pus in the back of the throat are all considered signs of strep. Strep is part of the same group of bacteria as flesh-eating disease, according to Medicine Net, and the white patches at the back of the throat represent bacterial damage. They're your first stop if you're trying to figure out whether you've got strep or not; strep itself is diagnosed via a throat swab, where the doctor will examine the antigens present in your throat bacteria and note whether strep is present, and give you antibiotics to treat it.

Another, more subtle difference between the two illnesses is whether you're sneezing and coughing. Sneezes and coughs are considered integral to how the body manifests flu, while they're exceptionally rare in cases of strep. (Or you may be exceptionally unlucky and have both at once, which does occasionally happen.) This includes all kinds of coughs, from dry coughing to chesty coughs that involve dislodging a lot of phlegm. If you are coughing or sneezing, remember to cover your nose and mouth and disinfect your hands regularly, as this is how the flu virus usually spreads.

Additionally, there's a subtle difference between the sore throat you get from strep, and the sore throat you'd get from the flu, though both are unpleasant. The sore throat that indicates strep is usually exceptionally rapid; it seems to come out of nowhere and develop strongly within several hours, while the sore throat associated with flu may come on over a period of days, and is likely going to be accompanied by phlegm.

However, both will likely prevent easy swallowing and may influence a patient's sense of taste — and both often mean swollen lymph nodes, so patients will literally be dealing with a pain in the neck — but people who are unsure about what they're suffering from are encouraged to think about the timeline of their sore throat, and whether it appeared very suddenly, as that often indicates strep.

Mixing up strep for flu and vice versa can cause serious issues with treatment, explains Dr. Barzin, because they're treated very differently. "For strep throat, you use an antibiotic to treat the illness. This helps with making the symptoms better, but also with preventing complications like rheumatic fever, ear infections, and tonsillar abscesses," he says. "For the flu, we will sometimes choose to treat with an antiviral medicine, but sometimes we just provide supportive care with symptom control." If you're diagnosed with one but really have the other, you could receive ineffective treatment, he tells Bustle. "Antibiotics are really only intended to treat bacterial infections. This would not be effective in treating viruses. Likewise, antivirals do not treat bacterial infections."

It's crucial to get to the doctor if your sore throat or fever feels like it's more intense than usual. If left untreated, strep throat can develop into other bacterial infections such as scarlet fever or even potentially septic shock, so it's really important to make sure whatever you have gets treated in a timely manner. If you're feeling rotten, it doesn't hurt to go to an urgent care — your doctor there can do a strep test, which can give you results back in 10 or 15 minutes, or diagnose your flu, which can potentially be made a little easier with antiviral medication. Don't delay getting answers that can help you feel better faster.

This post was originally published on January 30, 2018. It was updated on June 12, 2019.