What is Strep A?
Strep A, also known as Group A Streptococcal infections, is a type of bacteria that causes infections in the throat and skin. While it usually affects children, it can impact people of all ages.
There are more than 120 types of Group A Streptococcus bacteria. The infections they cause are usually mild and can be treated with antibiotics. However, if left untreated, they can lead to complications such as kidney inflammation and rheumatic fever.
Causes of Strep A
Strep A infections are caused by Group A Streptococcus bacteria. Symptoms are a result of both the damage caused by the bacteria and the body's immune response.
Symptoms of Strep A
Symptoms of Strep A infections vary depending on the severity of the infection. In mild infections, symptoms may include:
- Swelling of the tonsils and lymph nodes
- Difficulty swallowing
- Pain when swallowing
- Abdominal pain
- Headache
- Sore throat
- Red spots on the roof of the mouth
Skin Infection Symptoms
When Strep A infects the skin, symptoms may include:
- Rashes on the neck, armpits, and groin
- Yellow crusts on sores
- Sores that vary in color from red to purple on the nose, mouth, arms, and legs
- Discharge ranging from clear to yellow
- Itching
Severe Symptoms
In severe Strep A infections, symptoms may include:
- Diarrhea
- Swelling of the skin
- Dizziness
- Warmth when touching the swollen areas
- Fever
- Changes in skin color
- Large wounds, blisters, or black spots on the skin
- Pain spreading around the wound
- Nausea
- Vomiting
Transmission of Strep A
Strep A bacteria are contagious. They spread through contact, and transmission methods include:
- Touching infected areas
- Sharing utensils with an infected person
- Contact with nasal or oral secretions from an infected person
- Inhaling droplets from coughing or sneezing
Diagnosis Criteria for Strep A
Diagnosis of Strep A starts with a physical examination to check for symptoms. The severity and duration of symptoms are also assessed. Additional tests are performed to confirm the diagnosis, including:
- Blood tests to check for signs of infection
- Throat culture to identify the type of bacteria
- Biopsy to check for infection
- MRI, CT, and ultrasound imaging to assess damage beneath the skin
Strep A Testing
There are three types of tests used to diagnose Strep A:
Rapid Antigen Test
This test involves taking a throat swab to look for antigens. If the test is negative but suspicion remains, a throat culture is recommended.
Molecular Test (Polymerase Chain Reaction or PCR Test)
This test also involves a throat swab to identify the bacteria.
Throat Culture
A sample is taken from the tonsils to examine secretions under a microscope.
Treatment Methods for Strep A
Strep A infections can be treated with antibiotics. The type of antibiotic prescribed depends on the specific bacteria. Topical antibiotic creams are used for skin infections, and oral antibiotics are also prescribed.
The benefits of antibiotic treatment include:
- Preventing complications and severe illnesses
- Shortening the duration of the illness
- Preventing the spread of bacteria
- Minimizing symptoms
Medications prescribed for Strep A infections include:
- Antibiotics (penicillin, amoxicillin, benzathine)
- For those allergic to penicillin (clarithromycin, azithromycin, clindamycin, cefadroxil, cephalexin)
- Topical creams (mupirocin, retapamulin)
Diseases Caused by Strep A
Strep A infections can lead to serious complications. Antibiotic treatments significantly reduce these risks.
Spread of Infection
If Strep A bacteria spread, the following infections can occur:
- Middle ear infections
- Tonsillitis
- Bacteremia
- Sinusitis
- Skin infections
Inflammatory Reactions
Strep A bacteria can cause inflammatory diseases, including:
- Scarlet fever, characterized by a rash and sore throat
- Post-streptococcal reactive arthritis
- Kidney inflammation
- Rheumatic fever, affecting the joints, nervous system, and skin
Some studies have shown that Strep A bacteria can exacerbate symptoms of neuropsychiatric disorders like OCD and tic disorders in children. However, this is rare and not definitively proven.
Types of Strep A
Strep A bacteria can cause mild infections as well as life-threatening infections. Types of Strep A include:
Mild Strep Infections
Mild infections include:
- Cellulitis infections, targeting deep skin tissues
- Erysipelas, affecting the upper skin layers
- Impetigo, causing blisters and sores around the mouth and nose, arms, and legs
- Sore throat
- Strep throat, affecting the throat and tonsils
Severe Strep Infections
Strep A can cause various infections. The most common severe infections include:
- Bacteremia, defined as bloodstream infections
- Scarlet fever, presenting with redness, sore throat, and fever
- Toxic shock syndrome, defined as multiple organ infections
- Rheumatic fever, causing inflammatory tissues in the joints and heart
- Necrotizing fasciitis, also known as flesh-eating disease
