Mono VS. Strep Throat

Many illnesses can cause a sore throat, including infectious mononucleosis (mono) and streptococcal pharyngitis (strep throat). While these conditions have similar symptoms, there are key differences between the two.

Identifying whether your sore throat is caused by mono or strep is essential for managing and treating your illness. Here's what you need to know about the differences between mono and strep throat.

What is mono?

Mononucleosis¹ is a contagious disease caused by the Epstein-Barr virus. Because it's spread through saliva, it's sometimes referred to as "the kissing disease." Anyone can get mono, but it most commonly causes noticeable symptoms in teenagers and young adults. Children who catch mono usually don't have noticeable symptoms.

Because it’s caused by a virus, mono can’t be treated with antibiotics. There’s no medicine designed to cure or prevent mono. Symptoms can last as long as a month and significantly impact a person's life.

What is strep?

Strep throat² is an infection caused by group A streptococcus bacteria. Like mono, strep is spread through the exchange of bodily fluids, usually when an infected person talks, coughs, or sneezes. Typically, it takes two to five days for a person exposed to the bacteria to develop symptoms. Strep throat can be uncomfortable, but the condition is rarely severe.

That said, strep can lead to serious complications and should be treated.

Signs and symptoms of strep vs. mono

Mono is unpredictable. Some people experience severe symptoms, while others experience none. When symptoms are present, they come on slowly and typically don’t appear until weeks after exposure. Common signs of mono include:

• Sore throat

• Extreme tiredness

• Headache

• Fever

• Muscle weakness

• Lack of appetite

• Rash

• Swollen lymph nodes

• Enlarged spleen

Similarly, different people experience strep differently. Some people don’t even know they have strep throat, while others are in significant pain. Unlike mono, signs of strep come on suddenly. Common symptoms of strep throat include:

• Sore throat

• Swollen, red, or white-spotted tonsils

• Fever

• Headache

• Rash

• Body aches

• Swollen lymph nodes

• Red spots on the back of the roof of the mouth

Diagnosing strep and mono

Because mono and strep throat share many symptoms, including a sore throat, it's crucial to get a diagnosis so you can get the appropriate treatment (if treatment is necessary). 

Mono is usually diagnosed based on symptoms. It's important to note when your symptoms started, how long you’ve had them, and if they’re getting better or worse. Along with examining your throat, feeling your neck, and listening to your lungs, your healthcare provider will likely perform testing to rule out other conditions, such as strep throat. 

Strep throat can’t be diagnosed based on symptoms and physical examination alone; additional testing is necessary. To test for strep, your healthcare provider may use a swab to take a throat culture and test it for bacteria.

While throat culture tests are the most accurate test for diagnosing strep throat, they can take between 24 and 48 hours to produce results, so many providers prefer to use rapid antigen testing, which gives results in about 10 to 20 minutes. Unfortunately, rapid strep tests have a higher false negative³ rate, so if a person with symptoms of strep tests negative using a rapid test, it's best to follow up with a throat culture to confirm.

Treating strep and mono

There’s no vaccine to prevent mono and no medication to cure it. If you’ve been diagnosed with mono, there are steps you can take to alleviate your symptoms:

• Get plenty of rest

• Stay hydrated by drinking plenty of fluids

• Take over-the-counter medications for fever and pain

Do not take antibiotics if you have mono. They won’t help and can trigger a rash. Additionally, it's best to avoid contact sports until after you've recovered from mono to prevent your spleen from rupturing if it's become enlarged.

Antibiotics treat strep throat by killing the bacteria that causes it. This can help symptoms resolve faster. Antibiotics can also help prevent strep throat from developing into other rare but serious conditions, including kidney inflammation.

If your healthcare provider prescribes antibiotics to treat strep throat, it's important to take them as directed. Other steps to alleviate symptoms of strep throat include:

• Getting plenty of rest

• Drinking lots of fluids

• Taking over-the-counter medications for fever and pain

• Eating soft foods

• Gargling with warm salt water

Preventing strep and mono

Mono and strep throat are both contagious. The best way to avoid contracting both mono and strep throat is to practice good hygiene, including not kissing, eating, and drinking after, or using the personal items of someone who is sick with symptoms of the conditions.

When possible, stay away from individuals who have symptoms of mono or strep entirely. If you must be around them, wash your hands and disinfect shared surfaces often.

When to see a doctor

In most cases, mono and strep are minor medical conditions, but it's best to make an appointment with your healthcare provider when you develop a sore throat or other symptoms. Being examined by a medical professional early can help identify the cause of your symptoms and will ensure you’ll have an appropriate treatment plan and minimize your risk of complications.

Before your appointment, write down when your symptoms started, what medications you're taking, and any other information that may help your healthcare provider reach a diagnosis, such as family history or recent life changes. 

The lowdown

Mono and strep throat are both contagious infections. They’re spread through the exchange of bodily fluids and can present similar symptoms, including a sore throat.  Getting a diagnosis can help you manage your symptoms and avoid complications.

You can reduce your chances of catching mono or strep throat by practicing good hygiene habits, such as frequent hand washing and not drinking after others.