Acute Pharyngitis: Causes, Symptoms, Diagnosis, Treatment, and Prevention
Acute pharyngitis affects the throat and causes inflammation and pain. It can be caused by a variety of viral or bacterial infections, including the common cold, influenza, strep throat, and mononucleosis. If needed, antibiotics can be used to treat acute pharyngitis, which usually lasts for about two weeks.
Causes of Acute Pharyngitis
Acute pharyngitis can be caused by a variety of pathogens that infect the throat. The most common cause of acute pharyngitis is viral infection, which accounts for about 80% of cases. Virus infections include the common cold, influenza, mononucleosis, and others. Bacterial infections are the second most common cause of acute pharyngitis. Bacterial infections include strep throat, gonorrhea, chlamydia, diphtheria, and others. There are also less common causes of acute pharyngitis, such as fungal infections, parasites, allergic reactions, autoimmune diseases, drug reactions, trauma, and malignancies.
Symptoms of Acute Pharyngitis
As a result of acute pharyngitis, one may experience a sore throat, pharyngeal exudate, cough, fever, headache, fatigue, body aches, and chills depending on the underlying cause. The symptoms may vary depending on the age group affected. Children may have a fever below 38°C (100°F), runny nose, ear pain, and abdominal pain, while adults may suffer from fevers higher than 38°C (100°F), swollen lymph nodes, rash, and difficulty swallowing. The elderly may experience low-grade fever, dry cough, and confusion.
Diagnosis of Acute Pharyngitis
Based on the clinical presentation and suspected etiology, acute pharyngitis is diagnosed. Acute pharyngitis is most commonly caused by viral infection, which can be detected by rapid antigen detection or nucleic acid amplification for group A Streptococcus (GAS) pharyngitis. The results can be obtained within minutes of the point-of-care setting with these tests. In addition, they may miss some cases of GAS infection or give false-positive results due to cross-reactivity with other bacteria.
The diagnosis of bacterial infection requires a throat culture or a rapid antigen detection test for GAS pharyngitis. These tests are more sensitive than rapid antigen detection tests but may take longer to obtain results. Laboratory facilities and trained personnel are also necessary. In addition to urine cultures, blood cultures, and polymerase chain reactions (PCRs) for gonorrhea and chlamydia, additional tests may be required for the diagnosis of bacterial infections.
In order to diagnose Candida albicans pharyngitis, a throat culture or PCR are required. In addition to point-of-care tests, stool cultures or antigen detection tests for toxoplasmosis are available to diagnose parasitic infection, but they may have a lower sensitivity than laboratory tests. These tests are also available at point-of-care settings but may not be as sensitive as laboratory tests.
In order to diagnose allergic reactions, a history of exposure to allergens such as dust mites, animal dander, food, or insect venom is required. Symptoms of an autoimmune disease include fatigue, joint pain, rash, and organ dysfunction that suggest an underlying immune-mediated condition. A history of taking medications that may cause adverse effects, such as penicillin allergy, is required to diagnose a drug reaction. Trauma is diagnosed when blood or foreign bodies are ingested in the throat following an injury. A diagnosis of malignancy requires a history of risk factors such as smoking, alcohol use, infection with the human papillomavirus (HPV), or a family history of cancer.
Treatment of Acute Pharyngitis
The treatment of acute pharyngitis depends on the underlying cause but generally involves supportive care and antibiotics if needed. Supportive care includes:
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Drinking plenty of fluids to prevent dehydration
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Eating soft foods to avoid irritation
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Gargling with warm salt water to soothe sore throat
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Taking over-the-counter pain relievers such as acetaminophen (Tylenol) or ibuprofen (Advil) to reduce fever and pain
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Using nasal sprays or decongestants to relieve nasal congestion
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Using humidifiers or vaporizers to moisten the air
Antibiotics are indicated for bacterial infections such as GAS pharyngitis. The choice and duration of antibiotic therapy depend on the type and severity of infection. For example:
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A single dose of oral amoxicillin or intramuscular benzathine penicillin G is recommended for children younger than 5 years old who do not have a fever higher than 38°C (100°F), no rash, no sore throat lasting longer than three days after starting antibiotics, or no history of rheumatic fever.
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The use of oral penicillin V, amoxicillin, or cephalexin for GAS pharyngitis in children or adults older than 5 years old with fevers over 38°C (100°F), rash, sore throat lasting longer than 3 days after starting antibiotics, or history of rheumatic fever is recommended for a 10-day course.
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For GAS pharyngitis in patients who are allergic to penicillin, a 10-day course of oral erythromycin, azithromycin, clarithromycin, or clindamycin is recommended.
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For gonorrhea pharyngitis, a single dose of intramuscular ceftriaxone plus oral azithromycin or doxycycline is recommended.
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For chlamydia pharyngitis, a 7-day course of oral doxycycline or a single dose of oral azithromycin is recommended.
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For diphtheria pharyngitis, a 14-day course of intravenous or intramuscular penicillin G or erythromycin plus antitoxin is recommended.
Antiviral medications are indicated for viral infections such as influenza. The choice and duration of antiviral therapy depend on the type and severity of infection. For example:
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For influenza pharyngitis, a 5-day course of oral oseltamivir, zanamivir, or baloxavir is recommended within 48 hours of symptom onset.
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For mononucleosis pharyngitis, there is no specific antiviral treatment available, but corticosteroids may be used to reduce inflammation and swelling in severe cases.
A fungal or parasitic infection may require antifungal or antiparasitic medications, while an allergic reaction may require corticosteroids or antihistamines. Autoimmune diseases may require immunosuppressive medications. A drug reaction may require discontinuation of the offending agent and symptomatic treatment. Traumas may require surgical removal of foreign bodies, hemostasis of bleeding, and chemotherapy, radiotherapy, or surgery.
Prevention of Acute Pharyngitis
The prevention of acute pharyngitis depends on the underlying cause but generally involves avoiding exposure to infectious agents and boosting the immune system. Prevention measures include:
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Practicing good hygiene such as washing hands frequently, covering mouth and nose when coughing or sneezing, and disposing of tissues properly
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Avoiding sharing utensils, cups, or toothbrushes with others
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Avoiding contact with people who have symptoms of respiratory infections
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Getting vaccinated against influenza, diphtheria, and HPV
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Using condoms or dental dams during oral sex to prevent sexually transmitted infections
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Avoiding smoking or exposure to secondhand smoke
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Avoiding allergens or irritants that may trigger allergic reactions
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Eating a balanced diet rich in fruits, vegetables, and antioxidants
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Drinking enough water to stay hydrated
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Getting enough sleep and rest to reduce stress
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Exercising regularly to improve blood circulation and immunity
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Taking supplements such as vitamin C, zinc, or echinacea to enhance immune function
In most cases, acute pharyngitis is self-limiting and can be treated with supportive care as well as antibiotics. It can, however, also be caused by serious infections or conditions that require prompt diagnosis and treatment. Therefore, it is important to consult a doctor if the symptoms persist, are severe, or accompanied by other signs of complications. Health and well-being can be improved by following the prevention measures and reducing the risk of acute pharyngitis.
