What to take for sore throat due to allergies
|Points||Probability of Strep||Management|
|1 or fewer||<10%||No antibiotic or culture needed|
|2||11–17%||Antibiotic based on culture or RADT|
|4 or 5||52%||Empiric antibiotics|
A number of scoring systems exist to assist with diagnosis; however, their use is controversial due to insufficient accuracy. The modified Centor criteria are a set of five criteria; the entire score indicates the probability of a streptococcal infection.
One point is given for each of the criteria:
- Swollen and tender cervical lymph nodes
- Tonsillar exudate or swelling
- Absence of a cough
- Temperature >°C (°F)
- Age less than 15 (a point is subtracted if age >44)
A score of one may indicate no treatment or culture is needed or it may indicate the need to act out further testing if other high risk factors exist, such as a family member having the disease.
The Infectious Disease Society of America recommends against empirical treatment and considers antibiotics only appropriate when given after a positive test. Testing is not needed in children under three as both group A strep and rheumatic fever are rare, unless a kid has a sibling with the disease.
A throat culture is the gold standard for the diagnosis of streptococcal pharyngitis, with a sensitivity of 90–95%. A rapid strep test (also called rapid antigen detection testing or RADT) may also be used.
While the rapid strep test is quicker, it has a lower sensitivity (70%) and statistically equal specificity (98%) as a throat culture. In areas of the world where rheumatic fever is unusual, a negative rapid strep test is sufficient to law out the disease.
A positive throat culture or RADT in association with symptoms establishes a positive diagnosis in those in which the diagnosis is in doubt. In adults, a negative RADT is sufficient to law out the diagnosis. However, in children a throat culture is recommended to confirm the result. Asymptomatic individuals should not be routinely tested with a throat culture or RADT because a certain percentage of the population persistently «carries» the streptococcal bacteria in their throat without any harmful results.
See also: Acute pharyngitis
As the symptoms of streptococcal pharyngitis overlap with other conditions, it can be hard to make the diagnosis clinically. Coughing, nasal discharge, diarrhea, and red, irritated eyes in addition to fever and sore throat are more indicative of a viral sore throat than of strep throat. The presence of marked lymph node enlargement along with sore throat, fever, and tonsillar enlargement may also happen in infectious mononucleosis. Other conditions that may present similarly include epiglottitis, Kawasaki disease, acute retroviral syndrome, Lemierre’s syndrome, Ludwig’s angina, peritonsillar abscess, and retropharyngeal abscess.
Tonsillectomy may be a reasonable preventive measure in those with frequent throat infections (more than three a year). However, the benefits are little and episodes typically lessen in time regardless of measures taken. Recurrent episodes of pharyngitis which test positive for GAS may also represent a person who is a chronic carrier of GAS who is getting recurrent viral infections. Treating people who own been exposed but who are without symptoms is not recommended. Treating people who are carriers of GAS is not recommended as the risk of spread and complications is low.
Signs and symptoms
The typical signs and symptoms of streptococcal pharyngitis are a sore throat, fever of greater than 38°C (°F), tonsillar exudates (pus on the tonsils), and large cervical lymph nodes.
Other symptoms include: headache, nausea and vomiting, abdominal pain,muscle pain, or a scarlatiniform rash or palatal petechiae, the latter being an unusual but highly specific finding.
Symptoms typically start one to three days after exposure and final seven to ten days.
Strep throat is unlikely when any of the symptoms of red eyes, hoarseness, runny nose, or mouth ulcers are present.
It is also unlikely when there is no fever.
Mouth wide open showing the throat
A throat infection which on culture tested positive for group A streptococcus.
Note the large tonsils with white exudate.
A set of large tonsils in the back of the throat, covered in white exudate.
A culture positive case of streptococcal pharyngitis with typical tonsillar exudate in an 8-year-old.
Strep throat is caused by group A β-hemolytic Streptococcus (GAS or S.
pyogenes). Other bacteria such as non–group A β-hemolytic streptococci and fusobacterium may also cause pharyngitis. It is spread by direct, shut contact with an infected person; thus crowding, as may be found in the military and schools, increases the rate of transmission. Dried bacteria in dust are not infectious, although moist bacteria on toothbrushes or similar items can persist for up to fifteen days. Contaminated food can result in outbreaks, but this is rare. Of children with no signs or symptoms, 12% carry GAS in their pharynx, and, after treatment, approximately 15% of those remain positive, and are true «carriers».
The symptoms of strep throat generally improve within three to five days, irrespective of treatment. Treatment with antibiotics reduces the risk of complications and transmission; children may return to school 24 hours after antibiotics are istered. The risk of complications in adults is low. In children, acute rheumatic fever is rare in most of the developed world.
It is, however, the leading cause of acquired heart disease in India, sub-Saharan Africa and some parts of Australia.
Complications arising from streptococcal throat infections include:
The economic cost of the disease in the United States in children is approximately $ million annually.
Untreated streptococcal pharyngitis generally resolves within a few days. Treatment with antibiotics shortens the duration of the acute illness by about 16hours. The primary reason for treatment with antibiotics is to reduce the risk of complications such as rheumatic fever and retropharyngeal abscesses. Antibiotics prevent acute rheumatic fever if given within 9 days of the onset of symptoms.
Pain medication such as NSAIDs and paracetamol (acetaminophen) helps in the management of pain associated with strep throat. Viscous lidocaine may also be useful. While steroids may assist with the pain, they are not routinely recommended. Aspirin may be used in adults but is not recommended in children due to the risk of Reye syndrome.
The antibiotic of choice in the United States for streptococcal pharyngitis is penicillin V, due to safety, cost, and effectiveness.Amoxicillin is preferred in Europe. In India, where the risk of rheumatic fever is higher, intramuscular benzathine penicillin G is the first choice for treatment.
Appropriate antibiotics decrease the average 3–5 day duration of symptoms by about one day, and also reduce contagiousness. They are primarily prescribed to reduce rare complications such as rheumatic fever and peritonsillar abscess. The arguments in favor of antibiotic treatment should be balanced by the consideration of possible side effects, and it is reasonable to propose that no antimicrobial treatment be given to healthy adults who own adverse reactions to medication or those at low risk of complications. Antibiotics are prescribed for strep throat at a higher rate than would be expected from how common it is.
Erythromycin and other macrolides or clindamycin are recommended for people with severe penicillin allergies. First-generation cephalosporins may be used in those with less severe allergies and some evidence supports cephalosporins as superior to penicillin. These late-generation antibiotics show a similar effect when prescribed for days in comparison to the standard days of penicillin when used in areas of low rheumatic heart disease. Streptococcal infections may also lead to acute glomerulonephritis; however, the incidence of this side effect is not reduced by the use of antibiotics.