Strep throat

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Overview

Strep throat (or "Streptococcal pharyngitis", or "Streptococcal Sore Throat") is a form of Group A streptococcal infection that affects the pharynx.

Symptoms

• Sore throat
• Red and Black patches in the throat.
• Difficulty swallowing
• Tender cervical lymphadenopathy
• Red and enlarged tonsils
• Halitosis
• Fever of 101 F/38C or greater
• Rash
• Frequent cold chills
• Absence of cough
• White spots on tonsils
• Desquamation (peeling skin on fingertips) a few weeks after treatment

Diagnosis

Signs and symptoms

A study of 729 patients with pharyngitis in which 17% had a positive throat culture for group A streptococcus, identified the following four best predictors of streptococcus:

1. Lack of cough

• sensitivity = 56%
• specificity = 74%

2. Swollen tender anterior cervical nodes 3. (Marked) tonsillar exudates. Although the original study did not specify the degree of exudate, 'marked exudate' may be more accurate. A subsequent study of 693 patients with 9.7% having positive cultures found that 'marked exudates' had a sensitivity and specificity of 21% and 70% while 'pinpoint exudates' were nonspecific with sensitivity and specificity of 22% and 45%.

• sensitivity = 65%
• specificity = 69%

4. History of fever

• sensitivity = 78%
• specificity = 45%

5.hurts when swallowing.

When these findings are counted in a patient, the probabilities of positive cultures in the original study (prevalence=17%) are:

• 4 findings -> 55.7%
• 3 findings -> 30.1 – 34.1%
• 2 findings -> 14.1 – 16.6%
• 1 findings -> 6.0 - 6.9%
• 0 findings -> 2.5%

The probabilities can also be computed with the following equation: X = −2.69 + 1.04 (exudtons) + 1 (swolacn) - 0.95 (cough) + 0.89 (fevhist)

Tests

The throat of the patient is swabbed for culture or for a rapid strep test (5 to 10 min) which can be done in the doctor's office. A rapid test tests for the presence of antibodies against the bacteria. If the rapid test is negative, a follow-up culture (which takes 24 to 48 hours) may be performed. A negative culture suggests a viral infection, in which case antibiotic treatment should be withheld or discontinued.

A doctor will most likely prescribe Amoxicilin a.k.a Novamoxin.

Transmission

The illness is caused by the bacterium Streptococcus pyogenes and is spread by direct, close contact with an infected person via respiratory droplets (cough or sneezing). Casual contact rarely results in transmission. Rarely, contaminated food, especially milk and milk products, can result in outbreaks. Untreated patients are most infectious for 2-3 weeks after onset of infection. The incubation period, the period after exposure and before symptoms show up, is difficult to establish as some people don't become symptomatic. However, it is thought to be between two and five days. Strep is caused by bacteria of a type called group A beta-hemolytic streptococci. Symptoms include sore throat, fever, headache, and in some cases, chills, nausea, and vomiting. The patient usually experiences swelling of the tonsils and lymph nodes in the neck.

Treatment

Treatment will reduce symptoms slightly, minimize transmission, and reduce the likelihood of complications. Treatment consists of penicillin (orally for 10 days; or a single intramuscular injection of penicillin G). Erythromycin is recommended for penicillin-allergic patients. Second-line antibiotics include amoxicillin, clindamycin, and oral cephalosporins. Although symptoms subside within 4 days even without treatment, it is very important to start treatment within 10 days of onset of symptoms, and to complete the full course of antibiotics to prevent rheumatic fever, a rare but serious complication. Other complications that can occur include an ear infection, sinus infection, acute glomerulonephritis, or an abscess on the tonsils (peritonsillar abscess).

According to a meta-analysis in Pediatrics, the overall summary odds ratio (OR) for the bacteriologic cure rate significantly favored cephalosporins compared with penicillin (OR: 3.02; 95% confidence interval [CI]: 2.49 –3.67, with the individual cephalosporins [cephalexin, cefadroxil, cefuroxime, cefpodoxime, cefprozil, cefixime, ceftibuten, and cefdinir] showing superior bacteriologic cure rates). The overall summary OR for clinical cure rate was 2.33 (95% CI: 1.84 –2.97), significantly favoring cephalosporins. .

Penicillins should be avoided for treatment of a sore throat if bacterial (swab) confirmation has not been obtained since it causes a distinctive rash if the true illness proves to be viral. This rash is harmless but alarming. The most common virus illness responsible for strep-like symptoms is glandular fever, also known as mononucleosis. Typically, antibiotics such as clindamycin or clarithromycin will be prescribed if there is any doubt as to whether the infection is bacterial as it does not cause a rash in the presence of a virus.

In addition to taking antibiotics, other ways to relieve strep symptoms include taking nonprescription medications (such as ibuprofen and acetaminophen/paracetamol) for throat pain and fever reduction, and getting plenty of rest. Also, gargling with warm saltwater (1/4 teaspoon of table salt in 8 oz. warm water) can help relieve throat pain as well as warm, plain tea. Avoid orange juice or other citrus drinks. The acids in them may irritate the throat.

Lack of Treatment

The symptoms of strep throat usually improve even without treatment in five days, but the patient is contagious for several weeks. Lack of treatment or incomplete treatment of strep throat can lead to various complications. Some of them may pose serious health risks.

Infectious complications

• The active infection may occur in the throat, skin, and in blood.
• Skin and soft tissues may become infected, resulting in redness, pain, and swelling. Skin and deep tissues may also become necrotic (rare).
• Scarlet fever is caused by toxins released by the bacteria.
• Rarely, some strains may cause a severe illness in which blood pressure is reduced and lung injury and kidney failure may occur (toxic shock syndrome).

Noninfective complications

• During the infection, antibodies (disease–fighting chemicals) are produced. *Rare complication can result after the organism is cleared, when these antibodies cause disease in body organs.
• Rheumatic fever is a heart disease in which the inflammation of heart muscle and scarring of heart valves can occur.
• Glomerulonephritis is a kidney disease in which the injury may lead to kidney failure.

See also

• PANDAS - Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections
• Tonsillitis
• Pharyngitis
• Psoriasis

References

world book encyclopedia

External links

• Group A Streptococcal Infections - National Institute of Allergy and Infectious Diseases.
• Post-infectious glomerulonephritis - mayoclinic.com.