Quick answer: strep throat is a bacterial infection that starts suddenly, usually without a cough, and gets better within a day or two of starting antibiotics. Mono (infectious mononucleosis) is a viral illness that builds over several days, brings deep fatigue and swollen glands, and can last for weeks. Antibiotics do not treat mono. A rapid throat swab checks for strep and a blood test checks for mono, and it is possible to have both.
Mono vs. strep at a glance
- Cause: strep throat is caused by group A Streptococcus bacteria. Mono is most often caused by the Epstein-Barr virus.
- Who gets it: strep is most common in children 5 to 15 years old, though adults get it too. Mono is most common in teenagers and young adults.
- Time from exposure to illness: about 2 to 5 days for strep, and about 4 to 6 weeks for mono.
- How it starts: strep is sudden. Mono is gradual, often with several days of tiredness first.
- How long it lasts: strep improves within 1 to 2 days of antibiotics. Mono usually lasts 2 to 4 weeks, with fatigue that can linger longer.
- Treatment: antibiotics for strep. Rest, fluids, and symptom relief for mono.
Strep throat symptoms
- Sore throat that starts quickly, with pain on swallowing
- Fever
- Red, swollen tonsils, sometimes with white patches or streaks of pus
- Tiny red spots on the roof of the mouth
- Tender, swollen glands at the front of the neck
- Headache, stomach pain, nausea, or vomiting, especially in children
A cough, runny nose, hoarse voice, or pink eye points away from strep and toward a virus.
Mono symptoms
- Extreme fatigue
- Fever
- Sore throat, often with very swollen tonsils that may have a white coating
- Swollen glands in the neck, including the back of the neck, and in the armpits
- Head and body aches
- Enlarged spleen or liver
- Rash in some people
How each one is diagnosed
Strep: a rapid strep test is a quick throat swab with results during your visit. If the rapid test is negative in a child or teenager, a throat culture may be sent to make sure strep is not missed.
Mono: the diagnosis is usually based on symptoms and an examination, and blood tests help when the picture is unclear. A rapid mono (heterophile antibody) test can be falsely negative during the first week of illness, so a provider may also order a complete blood count or Epstein-Barr virus antibody tests.
We run rapid strep tests on site, and blood tests are drawn through our on-site laboratory.
Can you have mono and strep at the same time?
Yes. Some people with mono also test positive for strep. A positive strep test does not rule out mono, and if a sore throat and fatigue are not improving after a couple of days of antibiotics, ask about a mono test.
Treatment
Strep throat is treated with antibiotics, most often penicillin or amoxicillin. Antibiotics shorten the illness, reduce spread, and help prevent complications such as rheumatic fever. Finish the full course even when you feel better. People with strep should stay home until they have no fever and have taken antibiotics for at least 12 to 24 hours.
Mono has no specific medicine. Treatment is rest, fluids, and acetaminophen or ibuprofen for fever and throat pain. Two cautions apply:
- Protect the spleen. Avoid contact sports and heavy lifting for at least 3 to 4 weeks and until a provider clears you, because an enlarged spleen can rupture.
- Mention mono before taking antibiotics. Amoxicillin and ampicillin commonly cause a widespread rash in people with mono.
How each one spreads
Strep spreads through respiratory droplets and shared cups or utensils. Mono spreads mainly through saliva, which is why it is nicknamed the kissing disease, and the virus can be shed for weeks to months. For either illness, do not share drinks, utensils, or toothbrushes, and wash hands often.
When to come to urgent care
- A sore throat with fever that lasts more than 2 days
- A sore throat with swollen glands and no cough
- A sore throat with a new rash
- Fatigue and sore throat that are not improving after a week
- Known exposure to strep with new symptoms
Go to the emergency room or call 911 for trouble breathing, inability to swallow saliva or drooling, a muffled voice with severe throat pain on one side, a stiff neck, or sudden sharp pain in the upper left abdomen, which can be a sign of a spleen problem in mono.
Related guides: strep throat vs. tonsillitis and strep throat vs. flu. Sore throats are evaluated at our cold and flu service.
Walk in today, no appointment needed
Advanced Urgent Care of Pasadena is at 797 S Arroyo Pkwy, Pasadena, next to Petco, with free on-site parking. We are open Monday through Friday 8 AM to 8 PM and Saturday and Sunday 9 AM to 5 PM, and we take our last patient 30 minutes before closing. We serve Pasadena, South Pasadena, Altadena, San Marino, Alhambra, and nearby communities. Questions? Call (626) 304-0404.
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This article is general health information and is not a substitute for an examination by a medical provider. If you think you are having a medical emergency, call 911.