Strep throat is an infection caused by group A Streptococcus
bacteria, also known as Streptococcus pyogenes
, resulting in inflammation and swelling of the mucous membranes surrounding the tonsils and at the back of the throat. Strep throat is a contagious illness transmitted typically through airborne respiratory droplets. Therefore, individuals close to one another, such as in schools, daycare centers, and family households, often share the infection.1,2
Strep throat is most common in children and teens, although it can occur at any age. S pyogenes
tend to live in the nose and throat, so coughing, sneezing, and close contact can spread the infection. Although the infection is most likely to spread when symptoms are most severe, it can be transmitted for up to 3 weeks.3
Strep throat usually has an incubation period of 1 to 4 days after initial acquisition of the infection. Symptoms can range from mild to severe. Symptoms often include sudden onset throat pain, pain on swallowing, red tonsils and throat, swollen lymph nodes in neck, fever, headache, rash, nausea, vomiting, and body aches. White patches of pus can often be seen at the back of the throat and on the tonsils. Small red spots near the back of the soft or hard pallet are also sometimes seen (Figure4
It is important to note that the vast majority of sore throats are of viral origin and can have similar symptoms to strep throat.
Serious complications can arise if strep throat is not treated appropriately. Abscesses can form when a collection of pus develops around the tonsils or at the back of the throat. This will require frequent drainage and antibiotic therapy.2
Scarlet fever due to strep throat can result in a rough red rash and is usually seen in patients younger than 18 years. This disease is easily treated with antibiotics.1
Acute rheumatic fever is a serious complication that can occur 2 to 4 weeks after the onset of strep throat.1
The body’s immune system attacks joints, skin, and the heart, which can result in permanent damage to the heart valves or heart muscle and may result in congestive heart failure.
Poststreptococcal glomerulonephritis is an immune-mediated response most common in children younger than 12 years. This condition can lead to kidney damage, but frequently improves with treatment.1
Streptococcal toxic shock syndrome is caused by the release of toxins by group A Streptococcus
. This is a potentially life-threatening condition that causes low blood pressure, fever, rash, and potential organ failure.1
Strep throat can be definitively diagnosed using a rapid antigen detection test, which is done in office and takes about 10 minutes. If the test result is positive, strep throat is confirmed. A negative result does not automatically exclude strep throat because 5% to 30% of test results are false negative.1,5
If a rapid antigen test result is negative, a throat culture is generally sent to a lab for further testing. Throat cultures tend to take 24 to 48 hours and are considered the gold standard for diagnosis of strep throat.1,5
Predictive factors of strep throat that can help differentiate strep and viral infections include fever, absence of cough or runny nose, patient age between 5 and 15 years, early spring or late fall illness, redness and swelling of tonsils or throat with exudate, and enlarged and tender lymph nodes in the neck.1
Antibiotic therapy is indicated after a positive strep test result. Amoxicillin or penicillin is first-line therapy. If a patient is allergic to penicillins, cephalosporins or macrolide antibiotics are recommended alternatives. Antibiotics should be taken for a full 10 days, even though improvement may be seen within just a few days.4
The painful symptoms of strep throat can be managed with home remedies such as gargling with warm salt water, drinking warm liquids with honey or lemon, sucking on cold fruit pops or throat lozenges, using a vaporizer or humidifier, and taking OTC pain medications (eg, acetaminophen, ibuprofen).
Dr. Kenny earned her doctoral degree from the University of Colorado Health Sciences Center. She has 20+ years’ experience as a community pharmacist and works as a clinical medical writer based out of Colorado Springs, Colorado. Dr. Kenny is also the Colorado Education Director for the Rocky Mountain Chapter of the American Medical Writers Association and a regular contributor to
- Strep throat. emedicinehealth website. emedicinehealth.com/script/main/art.asp?articlekey=58851&pf=2. Accessed October 16, 2016.
- Strep throat. Mayo Clinic website. mayoclinic.org/diseases-conditions/strep-throat/symptoms-causes/dxc-20165964. Accessed October 16, 2016.
- Strep throat. KidsHealth website. kidshealth.org/en/parents/strep-throat.html?view=ptr&WT.ac=p-ptr. Accessed October 16, 2016.
- Strep throat. MedlinePlus website. https://medlineplus.gov/ency/article/000639.htm. Accessed October 16, 2016.
- Strep throat: topic overview. WebMd website. webmd.com/oral-health/tc/strep-throat-topic-overview#1. Accessed October 16, 2016.