Terry Ann Jankowski, MLS, AHIP

Evidence summary

In the US, GABHS is the cause of acute pharyn-gitis in 5% to 10% of adults and 15% to 30% of children. It is the only commonly occurring cause of pharyngitis with an indication for antibiotic therapy.¹ The main benefit of antibiotic treatment in adults is earlier symptom relief—1 fewer day of fever and pain if antibiotics are begun within 3 days of onset.

Antibiotic treatment also reduces the incidence of acute rheumatic fever, which complicates 1 case per 100,000 in most of the US and Europe (relative risk reduction [RRR]=0.28).² The risk of acute rheumatic fever is higher in some populaHawaiians (13–45 per 100,000).³ Treatment may also reduce suppurative complications (peritonsil-tions, particularly Native Americans and lar or retropharyngeal abscess), which occur in 1 case out of 1000.^2,4

A systematic review of the diagnosis of GABHS evaluated the accuracy of history and physical exam elements.⁵ Clinical prediction rules based on selected symptoms and signs can identify patients at low risk for GABHS. The 4 Centor criteria (history of fever, anterior cervical adenopathy, tonsillar exudates, absence of cough) are well validated in adult populations ( Table 1 ), while other clinical prediction rules (such as McIssac) are validated in populations with children and adults ( Table 2 ). The number of criteria present determines the likelihood ratio (LR), with which to calculate the posttest probability of GABHS.

The usefulness of clinical prediction rules depends on knowing how prevalent GABHS is among cases of pharyngitis in a particular community. In a typical US adult population, GABHS comprises 5% to 10% of cases. The presence of only 1 Centor criterion would reduce the probability of GABHS pharyngitis to 2% to 3%, while meeting all 4 criteria would raise the probability to 25% to 40%, an intermediate value ( Table 1 ). If the prevalence of GABHS pharyngitis were 50%, as in some Native communities in Alaska, meeting all 4 criteria would predict an 86% probability of pharyngitis due to GABHS. Performing additional testing for patients with intermediate or high probability based on clinical prediction rules reduces the likelihood of unnecessary antibiotic treatment.¹

A systematic review⁶ of RAD testing demonstrates that the newer techniques (optical immunoassay, chemiluminescent DNA probes) have a sensitivity of 80% to 90%, which compares closely with that of throat culture (90%–95%). Both have a specificity greater than 95%, so false-positive test results are uncommon (LR+ =16–19). Treatment based on a positive RAD test would result in few unnecessary antibiotic prescriptions.¹

A retrospective outcome study⁴ reviewed the frequency of suppurative complications of GABHS among 30,036 patients with pharyngitis diagnosed with either RAD testing or throat culture. Patients included adults and children in a primary care setting. Complication rates were identical. A prospective study of 465 suburban outpatients with pharyngitis assessed the accuracy of RAD diagnosis using throat culture as a reference. The RAD accuracy was 93% for pediatric patients and 97% for adults.⁵ In another retrospective review of RAD testing, investigators performed 11,427 RAD tests over 3 years in a private pediatric group. There were 8385 negative tests, among which follow-up cultures detected 200 (2.4%) that were positive for GABHS. In the second half of the study, a newer RAD test produced a false-negative rate of 1.4%.⁷ Because of the possibility of higher false-negative RAD test rates in some settings, unless the physician has ascertained that RAD testing is comparable to throat culture in their own setting, expert opinion recommends confirming a negative RAD test in children or adolescents with a throat culture.¹ Patients at higher risk of GABHS or GABHS complications may also warrant throat culture back up of RAD testing.¹

TABLE 1
Centor clinical prediction rules for diagnosis of GABHS (for adults)

TABLE 2
McIssac clinical prediction rules for diagnosis of GABHS (for adults and children)

Recommendations from others

The Infectious Diseases Society of America recommends that if the physician is unable to exclude the diagnosis of GABHS on epidemiological or clinical grounds, either RAD testing or throat culture should be done. A positive result warrants treatment for patients with signs and symptoms of acute pharyngitis. A negative RAD result for a child or adolescent should be confirmed by throat culture unless the physician has ascertained that the sensitivity of RAD testing and throat culture are comparable in his or her practice setting.¹

The American Academy of Pediatrics also recommends laboratory confirmation of GABHS pharyngitis in children with throat culture or RAD testing. If a patient suspected clinically of GABHS has a negative RAD test, a throat culture should be done. Since some experts believe RAD tests using optical immunoassay are sufficiently sensitive to be used without throat culture backup, physicians who wish to use them should validate them by comparison to throat culture in their practice.⁸

Evidence summary

In the US, GABHS is the cause of acute pharyn-gitis in 5% to 10% of adults and 15% to 30% of children. It is the only commonly occurring cause of pharyngitis with an indication for antibiotic therapy.¹ The main benefit of antibiotic treatment in adults is earlier symptom relief—1 fewer day of fever and pain if antibiotics are begun within 3 days of onset.

Antibiotic treatment also reduces the incidence of acute rheumatic fever, which complicates 1 case per 100,000 in most of the US and Europe (relative risk reduction [RRR]=0.28).² The risk of acute rheumatic fever is higher in some populaHawaiians (13–45 per 100,000).³ Treatment may also reduce suppurative complications (peritonsil-tions, particularly Native Americans and lar or retropharyngeal abscess), which occur in 1 case out of 1000.^2,4

A systematic review of the diagnosis of GABHS evaluated the accuracy of history and physical exam elements.⁵ Clinical prediction rules based on selected symptoms and signs can identify patients at low risk for GABHS. The 4 Centor criteria (history of fever, anterior cervical adenopathy, tonsillar exudates, absence of cough) are well validated in adult populations ( Table 1 ), while other clinical prediction rules (such as McIssac) are validated in populations with children and adults ( Table 2 ). The number of criteria present determines the likelihood ratio (LR), with which to calculate the posttest probability of GABHS.

The usefulness of clinical prediction rules depends on knowing how prevalent GABHS is among cases of pharyngitis in a particular community. In a typical US adult population, GABHS comprises 5% to 10% of cases. The presence of only 1 Centor criterion would reduce the probability of GABHS pharyngitis to 2% to 3%, while meeting all 4 criteria would raise the probability to 25% to 40%, an intermediate value ( Table 1 ). If the prevalence of GABHS pharyngitis were 50%, as in some Native communities in Alaska, meeting all 4 criteria would predict an 86% probability of pharyngitis due to GABHS. Performing additional testing for patients with intermediate or high probability based on clinical prediction rules reduces the likelihood of unnecessary antibiotic treatment.¹

A systematic review⁶ of RAD testing demonstrates that the newer techniques (optical immunoassay, chemiluminescent DNA probes) have a sensitivity of 80% to 90%, which compares closely with that of throat culture (90%–95%). Both have a specificity greater than 95%, so false-positive test results are uncommon (LR+ =16–19). Treatment based on a positive RAD test would result in few unnecessary antibiotic prescriptions.¹

A retrospective outcome study⁴ reviewed the frequency of suppurative complications of GABHS among 30,036 patients with pharyngitis diagnosed with either RAD testing or throat culture. Patients included adults and children in a primary care setting. Complication rates were identical. A prospective study of 465 suburban outpatients with pharyngitis assessed the accuracy of RAD diagnosis using throat culture as a reference. The RAD accuracy was 93% for pediatric patients and 97% for adults.⁵ In another retrospective review of RAD testing, investigators performed 11,427 RAD tests over 3 years in a private pediatric group. There were 8385 negative tests, among which follow-up cultures detected 200 (2.4%) that were positive for GABHS. In the second half of the study, a newer RAD test produced a false-negative rate of 1.4%.⁷ Because of the possibility of higher false-negative RAD test rates in some settings, unless the physician has ascertained that RAD testing is comparable to throat culture in their own setting, expert opinion recommends confirming a negative RAD test in children or adolescents with a throat culture.¹ Patients at higher risk of GABHS or GABHS complications may also warrant throat culture back up of RAD testing.¹

TABLE 1
Centor clinical prediction rules for diagnosis of GABHS (for adults)

TABLE 2
McIssac clinical prediction rules for diagnosis of GABHS (for adults and children)

Recommendations from others

The Infectious Diseases Society of America recommends that if the physician is unable to exclude the diagnosis of GABHS on epidemiological or clinical grounds, either RAD testing or throat culture should be done. A positive result warrants treatment for patients with signs and symptoms of acute pharyngitis. A negative RAD result for a child or adolescent should be confirmed by throat culture unless the physician has ascertained that the sensitivity of RAD testing and throat culture are comparable in his or her practice setting.¹

The American Academy of Pediatrics also recommends laboratory confirmation of GABHS pharyngitis in children with throat culture or RAD testing. If a patient suspected clinically of GABHS has a negative RAD test, a throat culture should be done. Since some experts believe RAD tests using optical immunoassay are sufficiently sensitive to be used without throat culture backup, physicians who wish to use them should validate them by comparison to throat culture in their practice.⁸

Evidence summary

In the US, GABHS is the cause of acute pharyn-gitis in 5% to 10% of adults and 15% to 30% of children. It is the only commonly occurring cause of pharyngitis with an indication for antibiotic therapy.¹ The main benefit of antibiotic treatment in adults is earlier symptom relief—1 fewer day of fever and pain if antibiotics are begun within 3 days of onset.

Antibiotic treatment also reduces the incidence of acute rheumatic fever, which complicates 1 case per 100,000 in most of the US and Europe (relative risk reduction [RRR]=0.28).² The risk of acute rheumatic fever is higher in some populaHawaiians (13–45 per 100,000).³ Treatment may also reduce suppurative complications (peritonsil-tions, particularly Native Americans and lar or retropharyngeal abscess), which occur in 1 case out of 1000.^2,4

A systematic review of the diagnosis of GABHS evaluated the accuracy of history and physical exam elements.⁵ Clinical prediction rules based on selected symptoms and signs can identify patients at low risk for GABHS. The 4 Centor criteria (history of fever, anterior cervical adenopathy, tonsillar exudates, absence of cough) are well validated in adult populations ( Table 1 ), while other clinical prediction rules (such as McIssac) are validated in populations with children and adults ( Table 2 ). The number of criteria present determines the likelihood ratio (LR), with which to calculate the posttest probability of GABHS.

The usefulness of clinical prediction rules depends on knowing how prevalent GABHS is among cases of pharyngitis in a particular community. In a typical US adult population, GABHS comprises 5% to 10% of cases. The presence of only 1 Centor criterion would reduce the probability of GABHS pharyngitis to 2% to 3%, while meeting all 4 criteria would raise the probability to 25% to 40%, an intermediate value ( Table 1 ). If the prevalence of GABHS pharyngitis were 50%, as in some Native communities in Alaska, meeting all 4 criteria would predict an 86% probability of pharyngitis due to GABHS. Performing additional testing for patients with intermediate or high probability based on clinical prediction rules reduces the likelihood of unnecessary antibiotic treatment.¹

A systematic review⁶ of RAD testing demonstrates that the newer techniques (optical immunoassay, chemiluminescent DNA probes) have a sensitivity of 80% to 90%, which compares closely with that of throat culture (90%–95%). Both have a specificity greater than 95%, so false-positive test results are uncommon (LR+ =16–19). Treatment based on a positive RAD test would result in few unnecessary antibiotic prescriptions.¹

A retrospective outcome study⁴ reviewed the frequency of suppurative complications of GABHS among 30,036 patients with pharyngitis diagnosed with either RAD testing or throat culture. Patients included adults and children in a primary care setting. Complication rates were identical. A prospective study of 465 suburban outpatients with pharyngitis assessed the accuracy of RAD diagnosis using throat culture as a reference. The RAD accuracy was 93% for pediatric patients and 97% for adults.⁵ In another retrospective review of RAD testing, investigators performed 11,427 RAD tests over 3 years in a private pediatric group. There were 8385 negative tests, among which follow-up cultures detected 200 (2.4%) that were positive for GABHS. In the second half of the study, a newer RAD test produced a false-negative rate of 1.4%.⁷ Because of the possibility of higher false-negative RAD test rates in some settings, unless the physician has ascertained that RAD testing is comparable to throat culture in their own setting, expert opinion recommends confirming a negative RAD test in children or adolescents with a throat culture.¹ Patients at higher risk of GABHS or GABHS complications may also warrant throat culture back up of RAD testing.¹

TABLE 1
Centor clinical prediction rules for diagnosis of GABHS (for adults)

TABLE 2
McIssac clinical prediction rules for diagnosis of GABHS (for adults and children)

Recommendations from others

The Infectious Diseases Society of America recommends that if the physician is unable to exclude the diagnosis of GABHS on epidemiological or clinical grounds, either RAD testing or throat culture should be done. A positive result warrants treatment for patients with signs and symptoms of acute pharyngitis. A negative RAD result for a child or adolescent should be confirmed by throat culture unless the physician has ascertained that the sensitivity of RAD testing and throat culture are comparable in his or her practice setting.¹

The American Academy of Pediatrics also recommends laboratory confirmation of GABHS pharyngitis in children with throat culture or RAD testing. If a patient suspected clinically of GABHS has a negative RAD test, a throat culture should be done. Since some experts believe RAD tests using optical immunoassay are sufficiently sensitive to be used without throat culture backup, physicians who wish to use them should validate them by comparison to throat culture in their practice.⁸

Evidence summary

Nasal congestion is the most common symptom of the common cold, and hundreds of millions of dollars are spent annually on decongestants. A Cochrane review of 4 randomized controlled trials compared single doses of oxymetazoline, pseudoephedrine, and phenylpropanolamine.¹ Included studies involved from 30 to 106 participants, were double-blinded and placebo-controlled, used either topical or oral decongestants for symptoms of less than 5 days’ duration, and measured either subjective or objective relief or adverse events. All 4 studies used nasal airway resistance as an objective measure of nasal congestion, and a combined symptom score as a subjective measure of relief. One study also administered a side-effect questionnaire.

In all studies, topical and oral decongestants were equally efficacious, producing a 13% reduction in subjective symptoms and a significant decrease in nasal airway resistance after 1 dose of decongestant. Only 1 study investigated repeated doses of decongestants and found no significant additional improvement from repeated doses over a 5-day period.

More studies are needed to evaluate efficacy of multiple doses. Clinical interpretation of these results must take into consideration that quality-of-life measures were not evaluated and that none of the studies included children under 12.

Limited data are available on decongestants in sinusitis. Most studies focused on the use of nasal corticosteroids. One placebo-controlled, randomized controlled trial evaluated the effect on mucociliary clearance from adding nasal saline, nasal steroids, or oxymetazoline to antibiotics in acute bacterial sinusitis.² The group using oxymetazoline increased mucociliary clearance immediately (within 20 minutes). However, at 3 weeks, the improvement in mucociliary clearance in the oxymetazoline group was not significantly different than in the other groups.

An additional prospective, placebo-controlled study evaluated improvement in x-ray findings as well as subjective symptoms in acute sinusitis using phenoxymethyl-penicillin (penicillin V) in combination with oxymetazoline or placebo administered via a variety of nasal delivery systems.³ Oxymetazoline was not significantly different from placebo. Controlled prospective studies are lacking to support the use of decongestants in acute sinusitis.

Recommendations from others

Expert opinion from Current Clinical Topics in Infectious Diseases does not recommend the use of decongestants in sinusitis or the common cold in the absence of concurrent allergic rhinosinusitis.⁴ This recommendation is based on the lack of evidence regarding efficacy and the known rebound congestion associated with topical decongestants. If a decongestant is prescribed, the oral route is preferred, with the understanding of potential significant side effects of nervousness, insomnia, tachycardia, and hypertension.

Evidence summary

Nasal congestion is the most common symptom of the common cold, and hundreds of millions of dollars are spent annually on decongestants. A Cochrane review of 4 randomized controlled trials compared single doses of oxymetazoline, pseudoephedrine, and phenylpropanolamine.¹ Included studies involved from 30 to 106 participants, were double-blinded and placebo-controlled, used either topical or oral decongestants for symptoms of less than 5 days’ duration, and measured either subjective or objective relief or adverse events. All 4 studies used nasal airway resistance as an objective measure of nasal congestion, and a combined symptom score as a subjective measure of relief. One study also administered a side-effect questionnaire.

In all studies, topical and oral decongestants were equally efficacious, producing a 13% reduction in subjective symptoms and a significant decrease in nasal airway resistance after 1 dose of decongestant. Only 1 study investigated repeated doses of decongestants and found no significant additional improvement from repeated doses over a 5-day period.

More studies are needed to evaluate efficacy of multiple doses. Clinical interpretation of these results must take into consideration that quality-of-life measures were not evaluated and that none of the studies included children under 12.

Limited data are available on decongestants in sinusitis. Most studies focused on the use of nasal corticosteroids. One placebo-controlled, randomized controlled trial evaluated the effect on mucociliary clearance from adding nasal saline, nasal steroids, or oxymetazoline to antibiotics in acute bacterial sinusitis.² The group using oxymetazoline increased mucociliary clearance immediately (within 20 minutes). However, at 3 weeks, the improvement in mucociliary clearance in the oxymetazoline group was not significantly different than in the other groups.

An additional prospective, placebo-controlled study evaluated improvement in x-ray findings as well as subjective symptoms in acute sinusitis using phenoxymethyl-penicillin (penicillin V) in combination with oxymetazoline or placebo administered via a variety of nasal delivery systems.³ Oxymetazoline was not significantly different from placebo. Controlled prospective studies are lacking to support the use of decongestants in acute sinusitis.

Recommendations from others

Expert opinion from Current Clinical Topics in Infectious Diseases does not recommend the use of decongestants in sinusitis or the common cold in the absence of concurrent allergic rhinosinusitis.⁴ This recommendation is based on the lack of evidence regarding efficacy and the known rebound congestion associated with topical decongestants. If a decongestant is prescribed, the oral route is preferred, with the understanding of potential significant side effects of nervousness, insomnia, tachycardia, and hypertension.

Evidence summary

Nasal congestion is the most common symptom of the common cold, and hundreds of millions of dollars are spent annually on decongestants. A Cochrane review of 4 randomized controlled trials compared single doses of oxymetazoline, pseudoephedrine, and phenylpropanolamine.¹ Included studies involved from 30 to 106 participants, were double-blinded and placebo-controlled, used either topical or oral decongestants for symptoms of less than 5 days’ duration, and measured either subjective or objective relief or adverse events. All 4 studies used nasal airway resistance as an objective measure of nasal congestion, and a combined symptom score as a subjective measure of relief. One study also administered a side-effect questionnaire.

In all studies, topical and oral decongestants were equally efficacious, producing a 13% reduction in subjective symptoms and a significant decrease in nasal airway resistance after 1 dose of decongestant. Only 1 study investigated repeated doses of decongestants and found no significant additional improvement from repeated doses over a 5-day period.

More studies are needed to evaluate efficacy of multiple doses. Clinical interpretation of these results must take into consideration that quality-of-life measures were not evaluated and that none of the studies included children under 12.

Limited data are available on decongestants in sinusitis. Most studies focused on the use of nasal corticosteroids. One placebo-controlled, randomized controlled trial evaluated the effect on mucociliary clearance from adding nasal saline, nasal steroids, or oxymetazoline to antibiotics in acute bacterial sinusitis.² The group using oxymetazoline increased mucociliary clearance immediately (within 20 minutes). However, at 3 weeks, the improvement in mucociliary clearance in the oxymetazoline group was not significantly different than in the other groups.

An additional prospective, placebo-controlled study evaluated improvement in x-ray findings as well as subjective symptoms in acute sinusitis using phenoxymethyl-penicillin (penicillin V) in combination with oxymetazoline or placebo administered via a variety of nasal delivery systems.³ Oxymetazoline was not significantly different from placebo. Controlled prospective studies are lacking to support the use of decongestants in acute sinusitis.

Recommendations from others

Expert opinion from Current Clinical Topics in Infectious Diseases does not recommend the use of decongestants in sinusitis or the common cold in the absence of concurrent allergic rhinosinusitis.⁴ This recommendation is based on the lack of evidence regarding efficacy and the known rebound congestion associated with topical decongestants. If a decongestant is prescribed, the oral route is preferred, with the understanding of potential significant side effects of nervousness, insomnia, tachycardia, and hypertension.