Mononucleosis vs. Strep Throat

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A sore throat is a common symptom of several illnesses, including infectious mononucleosis (mono) and a streptococcus infection (strep throat).

While both mono and strep produce a sore throat, they are distinct conditions with different additional symptoms and treatments.

It's important to know what to look for and how to handle each condition. Be sure to see a healthcare provider for a proper diagnosis.

A woman sits on her couch with her eyes closed, wrapped in a blanket, holding a mug in her right hand and touching her throat with her left hand.

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Causes Of Mono
  • Epstein-Barr virus (EBV)

  • Cytomegalovirus (CMV)

Causes Of Strep Throat
  • Group A streptococcus (group A strep) bacteria

Mono Causes

Mono is a contagious infection caused by a number of different viruses. Most often, the cause is the Epstein-Barr virus (EBV), which is a common virus that—by middle age—most people have had. Not everyone who contracts EBV will get mono.

Mono is most common among teenagers and young adults. In fact, at least one in four teenagers and young adults who contract EBV will develop mono from the infection. People of any age can still get mono, including children.

A milder form of mono can be caused by cytomegalovirus (CMV), another common virus similar to EBV.

Mono is sometimes called "the kissing disease" because it is spread through bodily fluids. It is usually spread via saliva and possibly contracted during sexual contact; rarely EBV infection can be contracted during blood transfusions or organ transplantation.

How Are Mono and Strep Throat Diagnosed?

In addition to a physical examination and a discussion about symptoms, healthcare providers can do a blood test to look for mono and/or do a throat swab to run a rapid strep test or do a culture to look for strep throat.

Strep Throat Causes

While viruses are the most common cause of sore throat overall, strep throat is caused by bacteria: typically group A streptococcus (group A strep) and less often groups C or G streptococcus.

Anyone can get strep throat, but it is most common in children and teenagers.

Untreated strep throat is more likely to spread when the symptoms are most severe, but can still infect others for up to three weeks.

The bacteria that cause strep throat live in the nose and throat and spread easily from person to person through contact with infected droplets created by coughing, sneezing, talking, and through contact with saliva (such as kissing, drooling, etc.).

Others can get sick if they:

  • Breathe in the droplets
  • Touch something that the droplets have landed on, and then touch their nose or mouth
  • Share personal items such utensils, food, cups, or dishes with an infected person
  • Touch sores created by impetigo (a skin infection caused by group strep A)


Symptoms Of Mono
  • Sore throat

  • Extreme fatigue

  • Fever

  • Swollen lymph nodes

  • Head and body aches

  • Loss of appetite

  • Swollen spleen and/or liver

  • Rash

  • Petechiae (pinpoint red or purple spots) on roof of mouth

  • Red and swollen tonsils (sometimes with white patches or streaks of pus)

Symptoms Of Strep Throat
  • Fever

  • Sore throat

  • Red and swollen tonsils

  • Swollen lymph nodes

  • Petechiae on roof of mouth

  • "Strawberry" look to tongue

  • Generally feeling ill

  • Nausea, stomach pain, and/or loss of appetite

  • "Sandpaper" body rash

Mono Symptoms

Symptoms of mono vary. They can be mild or severe, and they tend to come on gradually.

Symptoms of mono usually begin four to six weeks after infection with EBV, and may last for four weeks or longer.

Symptoms of mono include:

  • Sore throat
  • Extreme fatigue/tiredness
  • Fever
  • Swollen lymph nodes in the neck and armpits
  • Head and body aches
  • Muscle aches, stiffness, or weakness
  • Loss of appetite
  • Swollen liver or spleen or both
  • Rash
  • Petechiae (tiny, red or purple spots) on the roof of the mouth
  • Red and swollen tonsils (sometimes white patches or streaks of pus)

Less common symptoms include:

  • Puffy eyes
  • Nausea
  • Severe headache
  • Sensitivity to light
  • Chest pain
  • Trouble breathing

What Else Can Cause a Sore Throat?

Sore throats are usually caused by a virus like those that cause a cold or flu.

Bacterial infections like tonsillitis and some sexually-transmitted infections can also cause a sore throat.

Sore throats are sometimes caused by irritants like allergies, dry air, or cigarette smoke.

Injury, including strains caused by yelling or voice over-use, and conditions like gastroesophageal reflux disease (GERD), which causes stomach acid to move into the throat, may contribute to or cause a sore throat to develop.

A tumor or cancer can also cause a sore throat, but this is rare and lasts longer than the typical duration of a sore throat.

Strep Throat Symptoms

Symptoms of strep throat include:

  • Sore throat (can start suddenly)
  • Pain when swallowing
  • Fever (may begin suddenly; often highest on the second day)
  • Red and swollen tonsils (sometimes with white patches or streaks of pus)
  • Petechiae (tiny red spots) on the roof of the mouth
  • Swollen lymph nodes in the front of the neck
  • Headache
  • General discomfort, uneasiness, or feeling ill
  • Lower stomach pain
  • Nausea
  • Loss of appetite
  • "Strawberry" look to the tongue
  • Red rash on the body that "feels like sandpaper" (scarlet fever [scarlatina] may appear 12 to 48 hours after the first symptoms)

Symptoms that are not common with strep throat, and likely suggest a viral infection include:

  • Cough
  • Runny nose
  • Hoarseness
  • Red eyes


Complications of Mono
  • Long-term fatigue

  • Ruptured spleen

  • Liver involvement

  • Kidney inflammation

  • Nervous system problems

  • Hemolytic anemia

  • Heart problems

  • Obstruction of airways

Complications of Strep Throat
  • Abscesses

  • Sinus infections

  • Swollen lymph nodes

  • Ear infections

  • Rheumatic fever

  • Scarlet fever

  • Poststreptococcal glomerulonephritis

  • Guttate psoriasis

  • Poststreptococcal reactive arthritis

  • Streptococcal toxic shock syndrome

Mono Complications

Complications of mono are rare, but can include:

  • Fatigue that can last for months and may caused missed work or school
  • Ruptured spleen (may cause life-threatening internal bleeding; requires immediate emergency surgery)
  • Liver involvement/mild liver damage, temporary jaundice (a yellow discoloration of the skin and whites of the eyes)
  • Kidney inflammation
  • Nervous system problems such as encephalitis (inflammation of the brain), meningitis (inflammation of the fluid and membranes surrounding the brain and spinal cord), and other conditions
  • Hemolytic anemia (disorder in which red blood cells are destroyed faster than they can be made)
  • Inflammation of the heart muscle
  • Heart rhythm problems
  • Obstruction of the upper airways

Strep Throat Complications

Complication from strep throat can happen if the bacteria spread to other parts of the body. Serious complications from strep throat are uncommon.

Complications can include:

  • Abscesses (pockets of pus) around the tonsils
  • Sinus infections
  • Swollen lymph nodes in the neck
  • Ear infections
  • Rheumatic fever (disease that can affect the heart, joints, brain, and skin; can cause permanent heart damage)
  • Poststreptococcal glomerulonephritis (a kidney disease)
  • Guttate psoriasis (skin condition in which small, red, and scaly teardrop-shaped spots appear on the arms, legs, and middle of the body)
  • Scarlet fever


Treatments for Mono
  • No cure/do not use antibiotics

  • Rest

  • Drink fluids

  • Over-the-counter pain medicines

  • Sooth throat by gargling with salt water, using lozenges, etc.

  • Avoid sports and strenuous activity

Treatments for Strep Throat
  • Antibiotics

  • Drink warm and/or cold liquids

  • Take over-the-counter pain medicines

  • Sooth throat by gargling with salt water, using lozenges, etc.

  • Cool mist humidifier

  • Eat soft foods

Mono Treatments

There is no vaccine or cure for mono.

People with mono should not take penicillin antibiotics like ampicillin or amoxicillin as they will not be effective and can cause a rash in people who have mono.

Mono will go away on its own, with symptoms gradually improving after about four weeks (fatigue may last longer).

To help manage symptoms and prevent serious complications, people with mono can:

  • Get lots of rest
  • Drink lots of fluids (to avoid dehydration)
  • Take over-the counter pain relievers like ibuprofen, acetaminophen, or naproxen (people over age 12 unless directed by a healthcare provider); do not give aspirin to children, as it can cause a serious condition called Reye's syndrome
  • Gargle with salt water
  • Use throat lozenges (not for young children who are at risk for choking), or other throat pain relievers
  • Avoid sports (especially contact sports), strenuous exercise/activity, heavily lifting, and rough or active play while sick and for at least a month after (to avoid damage to or rupture of an enlarged spleen)

Medical treatment for some symptoms may be necessary, such as corticosteroids when needed to reduce swelling of the throat and tonsils.

Most people only get mono once, but EBV stays in the system for life, and can reactivate from time to time. Unless someone has a weakened immune system, these reactivations rarely cause symptoms, but people may unknowingly spread the reactivated virus to others.

Strep Throat Treatments

Strep throat is treated with antibiotics, usually penicillin or amoxicillin. Other antibiotics can be given if there are allergies to the first-choice antibiotics.

Antibiotics help to:

  • Decrease the length of illness
  • Relieve symptoms faster
  • Prevent the spread of bacteria to others
  • Prevent serious complications like rheumatic fever

Antibiotics are usually prescribed for about a 10 day course of treatment, and must be taken for the full course, even when symptoms are gone.

Fever usually goes away within 24 hours of starting antibiotics. Other symptoms should start dissipating by the second or third day.

Strep throat usually stops being contagious once the fever is gone and antibiotics have been taken for 24 hours or more. Antibiotics need to be continued until the prescribed course is done, but people can return to school, work, etc. once they feel well and are no longer contagious.

To help relieve symptoms, people can:

  • Drink warm liquids (lemon tea or tea with honey are quite soothing for sore throats; soup and hot chocolate are other good options)
  • Drink cold liquids
  • Suck on popsicles
  • Avoid orange juice, grapefruit juice, lemonade, or other acidic beverages
  • Take over-the-counter pain medicines, such as ibuprofen or acetaminophen (never give aspirin to children)
  • Gargle with warm salt water (1/2 tsp or 3 grams of salt in 1 cup or 240 milliliters water) several times a day (adults and older children who will not swallow the mixture)
  • Suck on hard candies or throat lozenges (older children and adults; these are choking hazards to young children)
  • Do not use throat sprays that contain benzocaine, as this could cause a drug reaction
  • Use a cool-mist vaporizer or humidifier
  • Eat/offer children soft foods to eat

Can Mono and Strep Throat Be Prevented?

The best way to prevent both is to practice good hygiene:

  • Wash hands with soap and water frequently
  • Cover coughs and sneezes
  • Don't share personal items like utensils and food
  • Don't kiss or be intimate with people who have mono or strep throat
  • Clean and disinfect shared surfaces
  • Promptly wash items such as dishes that have been used by a person who has mono or strep throat
  • If you or your child have mono or strep, tell others with whom you or your child have been in contact (particularly schools and daycares)

A Word From Verywell

While both mono and strep throat both cause a sore throat, they are different conditions with different causes, treatments, and potential complications.

Both conditions are usually not serious, but both can have potentially serious complications, some of which are long-term.

If you suspect you or your child has either mono or strep throat, it's important to see a healthcare provider for a proper diagnosis and course of treatment,

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Johns Hopkins Medicine. Infectious mononucleosis.

  2. Centers for Disease Control and Prevention. About mono (infectious mononucleosis).

  3. Centers For Disease Control. Strep throat: all you need to know.

  4. KidsHealth. Strep throat.

  5. Cleveland Clinic. Mononucleosis (mono): symptoms, treatment & diagnosis.

  6. Nationwide Children's. Mononucleosis (infectious): symptoms, diagnosis and treatment.

  7. Nationwide Children's. Strep throat (bacterial): symptoms, diagnosis and treatment.

  8. Mount Sinai. Strep throat information.

  9. KidsHealth. Mononucleosis (mono) (for parents).

By Heather Jones
Heather M. Jones is a freelance writer with a strong focus on health, parenting, disability, and feminism.