Strep Throat: Symptoms, Causes & Treatment Guide

What Is Strep Throat and What Causes It?

Strep throat is a bacterial infection of the tonsils caused by Group A Streptococcus (GAS) bacteria. It accounts for 15-30% of sore throats in children and 5-15% in adults, with peak occurrence in late winter and early spring. The bacteria spread through respiratory droplets and direct contact.

Strep throat, medically known as streptococcal pharyngitis or acute streptococcal tonsillitis, is an infection that affects the tonsils and the surrounding throat tissue. The tonsils are two oval-shaped glands located on each side of the back of the throat, roughly at the level of the base of the tongue. In adults, the tonsils are typically about the size and shape of almonds, though they are considerably larger in children and gradually shrink during adolescence.

The tonsils are composed of lymphoid tissue, which is a vital component of the body's immune system. They serve as a first line of defense, protecting the respiratory tract and digestive system from invading pathogens. When bacteria or viruses enter through the mouth or nose, the tonsils help trap and neutralize these threats before they can spread deeper into the body.

The most common bacterial cause of strep throat is Group A Streptococcus (GAS), also known as Streptococcus pyogenes. This gram-positive bacterium is highly contagious and can cause a range of infections from mild sore throat to more serious conditions. Interestingly, many people carry streptococcal bacteria in their throats without experiencing any symptoms whatsoever. This asymptomatic carriage is particularly common among children in daycare and school settings. People who carry the bacteria without symptoms generally don't spread the infection to others and don't require treatment unless they develop active symptoms.

Viral vs. Bacterial Sore Throats

It's important to understand that not all sore throats are caused by bacteria. In fact, the majority of sore throats are caused by viral infections, most commonly the viruses responsible for the common cold. The key distinguishing factor is that viral sore throats are typically accompanied by other cold symptoms such as runny nose, nasal congestion, cough, and hoarseness. Bacterial strep throat, on the other hand, characteristically presents without these accompanying cold symptoms.

This distinction is clinically important because antibiotics are only effective against bacterial infections. Prescribing antibiotics for viral infections provides no benefit to the patient while contributing to antibiotic resistance and exposing the patient to potential side effects. Healthcare providers use specific criteria and diagnostic tests to differentiate between viral and bacterial causes of sore throat.

Other Bacterial Causes

While Group A Streptococcus is by far the most common bacterial cause of tonsillitis, other bacteria can occasionally cause similar infections. One notable example is Vincent's angina (also called acute necrotizing ulcerative gingivitis or ANUG), which is a bacterial infection that typically affects only one side of the throat. In Vincent's angina, the affected tonsil becomes inflamed and develops a grayish-yellow coating, sometimes with ulceration. Although the symptoms are similar to streptococcal tonsillitis, this condition requires different treatment approaches.

What Are the Symptoms of Strep Throat?

The hallmark symptoms of strep throat include sudden severe sore throat, pain when swallowing, fever (often above 38°C/100.4°F), and swollen tender lymph nodes in the neck. Importantly, strep throat does NOT typically cause cough, runny nose, or sneezing - the presence of these cold symptoms suggests a viral cause.

Strep throat symptoms typically develop suddenly, often within 1-3 days after exposure to the bacteria. The presentation differs somewhat between children and adults, and recognizing the characteristic pattern of symptoms can help distinguish bacterial strep throat from viral causes of sore throat.

Classic Symptoms in Adults

The most prominent symptom of strep throat is a severe sore throat that hurts when swallowing. This pain is typically more intense than the discomfort experienced with a common cold. Many patients describe the sensation as sharp or stabbing, particularly when trying to swallow food, liquids, or even saliva. The throat pain often appears suddenly and can be severe enough to make eating and drinking difficult.

Fever is another cardinal symptom, typically developing alongside or shortly after the onset of throat pain. The fever can range from mild to high (often exceeding 38°C or 100.4°F) and may be accompanied by chills, general malaise, and body aches. The combination of high fever with severe sore throat in the absence of cold symptoms is highly suggestive of streptococcal infection.

Swollen lymph nodes in the neck are a characteristic finding in strep throat. These enlarged lymph nodes feel like tender lumps under the skin, usually located just below the jaw on both sides of the neck. When pressed, they are typically painful. The lymph node swelling is the body's immune response to the bacterial infection and indicates that the immune system is actively fighting the pathogen.

Symptoms in Children

Young children may have difficulty communicating exactly where the pain is located. It's common for children with strep throat to complain of headache, ear pain, or stomach pain rather than specifically pointing to their throat. Parents should be alert to behavioral changes that might indicate throat pain, such as refusing to eat or drink, increased irritability, or difficulty sleeping.

It's worth noting that strep throat is uncommon in children under 3 years of age. When very young children do present with sore throat, viral causes are far more likely. The peak incidence of strep throat occurs in school-age children between 5 and 15 years old.

Physical Examination Findings

When a healthcare provider examines someone with strep throat, several characteristic findings may be observed. The tonsils typically appear red and swollen, often significantly larger than normal. In many cases, there will be visible white or yellowish patches of pus (exudates) on the surface of the tonsils. The back of the throat may appear inflamed and red.

Another notable finding can be petechiae - small red spots on the soft palate (the back part of the roof of the mouth). While not always present, petechiae are relatively specific for streptococcal infection when observed. Additionally, some patients develop a characteristic sandpaper-like skin rash along with their sore throat and fever. When this triad of symptoms occurs together, it indicates scarlet fever, which is caused by strep bacteria that produce a specific toxin.

When Should You See a Doctor for Sore Throat?

See a doctor if you have sore throat with fever lasting several days without cold symptoms, difficulty swallowing or opening your mouth, visible swelling on one side of the throat, or sore throat with a rash. Seek emergency care immediately for severe breathing difficulties, inability to swallow liquids, or drooling.

Most sore throats that occur alongside common cold symptoms do not require medical evaluation. These viral infections typically resolve on their own within a week with supportive care. However, certain presentations warrant prompt medical attention to rule out bacterial infection or identify potential complications.

Schedule a Medical Appointment If:

You should contact a healthcare provider as soon as possible if you experience any of the following combinations of symptoms:

• Sore throat with fever lasting several days without accompanying cold symptoms like cough, runny nose, or nasal congestion
• Sore throat with visible external neck swelling - this could indicate significant lymph node enlargement or a developing abscess
• Sore throat, fever, and small bumpy skin rash - this combination may indicate scarlet fever, which requires antibiotic treatment
• Persistent sore throat lasting more than two weeks without other symptoms - prolonged symptoms warrant evaluation

If your regular healthcare provider's office is closed, you can wait until it reopens for these non-emergency situations. There's no need to seek care at an emergency department overnight for these symptoms.

What Can You Do at Home to Feel Better?

Home care for strep throat includes drinking plenty of fluids (both warm and cold can soothe the throat), eating soft cold foods like yogurt or ice cream, using throat lozenges, and taking over-the-counter pain relievers. Sugar-free lozenges are best to protect dental health.

While waiting for antibiotics to take effect, or if managing a viral sore throat, there are several strategies that can help relieve discomfort and support recovery. These supportive measures can significantly improve quality of life during the illness.

Hydration and Nutrition

Maintaining adequate fluid intake is essential when fighting any infection. However, drinking may be challenging when swallowing is painful. The good news is that both warm and cold beverages can have a soothing effect on an inflamed throat. Some people find that warm liquids like tea with honey feel comforting, while others prefer cold drinks. There's no medical advantage to one temperature over another - choose whatever feels most comfortable for you.

Appetite often decreases during throat infections, which is a normal response. Don't force yourself to eat large meals, but try to maintain some nutritional intake. Cold, soft foods like yogurt, ice cream, smoothies, or gelatin desserts can be easier to swallow and may even provide temporary relief from throat pain through their cooling effect. Avoid spicy, acidic, or rough-textured foods that might further irritate the throat.

Throat Lozenges and Sprays

Over-the-counter throat lozenges (available at pharmacies and many grocery stores) can provide symptomatic relief. While these products don't reduce the underlying inflammation or fight the infection, the act of sucking on something stimulates saliva production, which can have a lubricating and soothing effect on irritated throat tissues. Some lozenges contain mild anesthetic or antiseptic ingredients that may provide additional temporary relief.

For dental health, it's advisable to choose sugar-free lozenges when possible, particularly if you'll be using them frequently. Some medicated throat sprays are also available and can provide targeted relief to specific areas of the throat.

Pain and Fever Management

Several over-the-counter medications can help manage the pain and fever associated with strep throat. These include:

• Acetaminophen (paracetamol) - effective for both pain and fever reduction
• Ibuprofen - provides pain relief, fever reduction, and has anti-inflammatory properties
• Aspirin - suitable for adults only (never give aspirin to children or teenagers due to the risk of Reye's syndrome)

Always follow the dosing instructions on the product packaging, and consult a pharmacist if you're unsure which medication is most appropriate for your situation or if you're taking other medications. Some throat sprays and lozenges containing mild local anesthetics can also help numb the throat temporarily.

How Is Strep Throat Diagnosed?

Strep throat is diagnosed through physical examination plus laboratory testing. A rapid strep test provides results within minutes and is highly accurate when positive. If the rapid test is negative but strep is still suspected, a throat culture may be performed, with results available in 1-2 days.

Accurate diagnosis of strep throat is important because it determines whether antibiotic treatment is necessary. While the symptoms and physical examination can suggest bacterial infection, only laboratory testing can definitively confirm the presence of Group A Streptococcus bacteria.

Clinical Examination

The diagnostic process begins with a thorough medical history and physical examination. Your healthcare provider will ask about your symptoms, their duration, and whether you've been exposed to anyone with known strep throat. They will then examine your throat using a light source and a tongue depressor to visualize the tonsils and back of the throat. The examination typically takes only a few seconds and may cause brief discomfort.

The provider will also palpate your neck to assess for enlarged or tender lymph nodes, which commonly accompany streptococcal infection. Based on the clinical presentation, they will determine whether laboratory testing is warranted.

Rapid Strep Test

The most common diagnostic test is the rapid antigen detection test (RADT), commonly called a "rapid strep test." This test uses a throat swab to collect a sample from the tonsils and back of the throat. The swab is then tested for the presence of streptococcal antigens, with results available within minutes.

A positive rapid strep test is highly reliable and confirms the diagnosis of streptococcal pharyngitis. However, a negative rapid test doesn't completely rule out strep throat, as these tests can occasionally miss the infection (false negatives occur in approximately 5-20% of cases).

Your healthcare provider may decide not to perform a rapid strep test if:

• The clinical presentation strongly suggests a viral cause and antibiotics are unlikely to help
• You've recently had a confirmed strep infection - residual dead bacteria can cause false positive results

Throat Culture

A throat culture is the gold standard for diagnosing strep throat and is more accurate than the rapid test. The sample is collected in the same way (throat swab), but instead of testing for antigens, the bacteria are grown in a laboratory over 1-2 days. This allows for definitive identification of Group A Streptococcus and can also identify other bacterial causes of pharyngitis.

Throat cultures are typically performed when:

• The rapid strep test is negative but clinical suspicion for bacterial infection remains high
• You've had recurring strep infections within a short period
• Your healthcare provider wants to identify the specific type of bacteria causing the infection

How Is Strep Throat Treated?

Strep throat is treated with antibiotics, typically penicillin V or amoxicillin for 10 days. Antibiotics reduce symptom duration, prevent transmission after 24 hours, and most importantly prevent serious complications like rheumatic fever. It's crucial to complete the entire antibiotic course even if you feel better.

Once strep throat is confirmed through testing, antibiotic treatment is recommended for several important reasons. While the infection might eventually resolve on its own, antibiotics provide significant benefits that make treatment worthwhile.

Why Antibiotics Are Important

The benefits of antibiotic treatment for strep throat include:

• Faster symptom relief: Most patients notice significant improvement within 24-48 hours of starting antibiotics
• Reduced contagiousness: After approximately 24 hours of antibiotic therapy, you are generally no longer contagious to others
• Prevention of complications: Antibiotics significantly reduce the risk of serious complications including rheumatic fever, peritonsillar abscess, and acute glomerulonephritis (kidney inflammation)
• Prevention of spread: By shortening the contagious period, you help protect family members, classmates, or coworkers

Recommended Antibiotic Regimens

The first-line treatment for strep throat is penicillin V (phenoxymethylpenicillin) taken orally for 10 days. This antibiotic has been used for decades and remains highly effective against Group A Streptococcus, which has not developed significant resistance to penicillin. Amoxicillin is an alternative that is often preferred for children because it tastes better and can be taken less frequently.

For patients with penicillin allergies, alternative antibiotics include:

• Cephalosporins (such as cephalexin) - for those with non-severe penicillin allergies
• Azithromycin or clarithromycin - macrolide antibiotics used when penicillins and cephalosporins cannot be used
• Clindamycin - another option for penicillin-allergic patients

Treatment for Vincent's Angina

If the bacterial infection is identified as Vincent's angina rather than streptococcal tonsillitis, treatment involves antibiotics (often different from those used for strep) combined with gentle cleaning of the affected area of the throat.

When Surgery May Be Considered

Tonsillectomy (surgical removal of the tonsils) may be recommended for people who experience frequent episodes of strep throat. Generally, this is considered when a patient has had three to five or more episodes of documented strep throat within one to two years, particularly if they haven't responded well to antibiotic treatment with agents like clindamycin or cefadroxil.

The decision to proceed with tonsillectomy is made on an individual basis, weighing the frequency and severity of infections against the risks and recovery period associated with surgery.

Managing Household Contacts

Strep throat spreads easily among people living together, and it's common for multiple household members to become infected. If several people in a household are experiencing repeated strep infections, it may be beneficial for a healthcare provider to examine all household members, including those who are asymptomatic. Sometimes, apparently healthy family members carry streptococcal bacteria and can continue spreading it to others. In such cases, treating all carriers simultaneously can help break the cycle of reinfection.

Why Do Some People Get Strep Throat Repeatedly?

Recurrent strep throat within a month can occur due to reinfection from another person, bacteria surviving in the tonsils, or contaminated items like toothbrushes. Different antibiotics may be prescribed for recurrent infections, and boiling your toothbrush for 3-4 days after starting antibiotics helps prevent reinfection.

Getting strep throat again within a month of an initial infection is fairly common and can be frustrating for patients. There are several reasons why this might occur, and understanding these can help prevent repeated episodes.

Causes of Recurrent Infection

Recurrence can happen because:

• Reinfection from others: You may have been exposed to and infected by another person carrying the bacteria
• Bacterial persistence: The bacteria may have survived within the deep crevices of the tonsils despite antibiotic treatment
• Incomplete antibiotic course: Not completing the full prescribed course of antibiotics increases the risk of recurrence
• Antibiotic resistance: In rare cases, the bacteria may be resistant to the prescribed antibiotic

Treatment of Recurrent Strep Throat

If you develop strep throat again within a month of your initial infection, your healthcare provider will typically prescribe a different antibiotic. This is because the recurrence may indicate that the original antibiotic wasn't fully effective in eliminating the bacteria, or that different bacterial strains are involved.

Preventing Reinfection

One important but often overlooked step in preventing recurrence is properly handling your toothbrush. Streptococcal bacteria can survive on toothbrush bristles, potentially reinfecting you after your antibiotic course is complete. To prevent this:

• Boil your toothbrush after each use for the first 3-4 days after starting antibiotics
• Alternatively, replace your toothbrush once you're no longer contagious (about 24 hours after starting antibiotics)
• For children, also clean any pacifiers and toys that they frequently put in their mouths

How Does Strep Throat Spread and How Long Are You Contagious?

Strep throat spreads through respiratory droplets (coughing, sneezing) and direct contact. The incubation period is 1-2 days. Without treatment, you're contagious from before symptoms appear until weeks afterward. With antibiotics, you stop being contagious after about 24 hours of treatment.

Understanding how strep throat spreads can help you protect yourself and others from infection. The bacteria are transmitted relatively easily through several routes.

Transmission Routes

Group A Streptococcus bacteria spread through:

• Respiratory droplets: When an infected person coughs or sneezes, tiny droplets containing bacteria can be inhaled by others nearby or land on surfaces
• Direct contact: Touching an infected person (such as shaking hands) and then touching your own face, especially the mouth, nose, or eyes
• Shared items: Using the same cups, utensils, towels, or other personal items as an infected person

Timeline of Contagiousness

The period during which you can spread strep throat to others follows this general pattern:

• Incubation period: 1-2 days from exposure until symptoms appear
• Before symptoms: You may begin spreading bacteria a day or two before you notice you're sick
• Without treatment: You can remain contagious for weeks after symptoms begin
• With antibiotics: You typically stop being contagious after about 24 hours of treatment

Returning to School or Work

If you're taking antibiotics for strep throat, you should stay home for at least the first 24-48 hours of treatment. After that period, if you're feeling well enough, you can return to work, school, or other activities. Without antibiotic treatment, you should stay home until you feel significantly better and have been fever-free (without fever-reducing medication) for at least 24 hours.

For children, additional considerations apply: they should be well enough to participate in normal daily activities, including being active throughout the entire school day, before returning to daycare or school.

Prevention Strategies

To reduce your risk of contracting or spreading strep throat:

• Wash hands frequently with soap and water, especially after contact with potentially infected individuals
• Avoid sharing personal items like towels, drinking glasses, utensils, and especially toothbrushes
• Don't shake hands with people who are visibly ill, or wash your hands promptly afterward
• Cover coughs and sneezes with a tissue or your elbow, not your hands
• Stay home when sick to avoid spreading the infection to others

What Are the Possible Complications of Strep Throat?

Complications from strep throat are uncommon when treated properly, but can include peritonsillar abscess (the most common), rheumatic fever, acute glomerulonephritis (kidney inflammation), and ear infections. Antibiotic treatment significantly reduces the risk of these complications.

While most cases of strep throat resolve without lasting effects, especially with appropriate antibiotic treatment, untreated or inadequately treated infections can occasionally lead to serious complications. Understanding these potential complications underscores the importance of proper diagnosis and treatment.

Peritonsillar Abscess

The most common complication of strep throat is a peritonsillar abscess (also called quinsy). This occurs when the infection spreads beyond the tonsil itself and pus collects in the space behind the tonsil, causing significant swelling that usually affects only one side of the throat.

Symptoms of peritonsillar abscess include:

• Return of fever after having been fever-free for a couple of days
• Feeling tired and unwell
• Difficulty opening the mouth (trismus)
• Increased difficulty swallowing and breathing
• Voice changes - often described as a "hot potato" voice
• Deviation of the uvula toward the unaffected side

Treatment of peritonsillar abscess typically requires a specialist (ear, nose, and throat physician). The procedure involves draining the abscess - the patient remains seated and receives local anesthesia (spray and injection) before the doctor opens the abscess to release the pus. While uncomfortable, most patients experience significant relief once the pressure from the pus is released. Oral antibiotics are prescribed for continued treatment at home.

Follow-up appointments are important because the abscess can refill with pus and require additional drainage. Children who develop peritonsillar abscesses, or adults who have had two or more episodes, may be recommended for tonsillectomy to prevent future occurrences.

Rheumatic Fever

Rheumatic fever is a serious inflammatory condition that can develop as a delayed complication of untreated strep throat, typically appearing 2-4 weeks after the initial infection. This condition primarily affects the heart, joints, brain, and skin. While rheumatic fever has become relatively rare in developed countries due to widespread antibiotic use, it remains a concern in areas with limited healthcare access.

Rheumatic fever can cause permanent damage to the heart valves (rheumatic heart disease), which is why preventing this complication is one of the main reasons antibiotics are recommended for strep throat.

Other Complications

Additional complications that can occasionally follow strep throat include:

• Acute glomerulonephritis: An inflammation of the kidneys that typically develops 1-2 weeks after a strep infection. While it can cause symptoms like blood in the urine and swelling, most cases resolve completely
• Ear infection (otitis media): The bacteria can spread through the Eustachian tube to the middle ear, causing ear pain and potentially requiring additional treatment
• Sinusitis: Spread of infection to the sinuses
• Post-streptococcal reactive arthritis: Joint inflammation that can occur after strep infection