Staph Infection Diagnosis and Treatment
Staph infections need to be confirmed by your doctor, who will visually inspect the affected skin area. If a serious staph infection is suspected, either a tissue sample or nasal secretion can be collected by a laboratory and cultured for signs of the bacteria. Laboratory testing can not only confirm the diagnosis, but it can also be helpful in determining which antibiotic will be most effective against a particular strain of bacteria.
- Antibiotic therapy serves as the conventional method of treatment.
- Minor skin infections can usually be treated successfully with an antibiotic ointment.
- Topical or oral antibiotics may be prescribed to treat infected skin, especially if these areas involve eczema lesions.
- Penicillin use to work well against staph infections, but as bacterial resistance developed to this drug, other antibiotics, such as methicillin, cloxacillin, and didoxacillin have been used. However, bacterial resistance to these agents is increasing.
- Some strains of staph bacteria, such as MRSA, are resistant to many common antibiotics. Consequently, the use of stronger and more toxic antibiotics may be necessary to control the infection.
- Intravenous antibiotics are used to treat serious and life-threatening infections.
- Surgical drainage may be required if abscesses are present. Advanced infections that spread deep into muscles or muscle fibers will require surgical cleaning.
- To minimize this incidence of MRSA, patients must strictly follow dosage instructions and finish all of the prescribed oral antibiotics.
Decolonization of Staphylococcus aureus
A study investigating nasal carriage as a source of S. aureus concluded that a substantial proportion of staph infections originate from bacterial colonies located in the mucus lining of the nasal passages [von Eiff C, et al. Nasal carriage as a source of Staphylococcus aureus bacteremia. Study Group. N Engl J Med. 2001 Jan 4;344(1):11-6]. The study strongly recommends that irradication of colonization should be the main strategy for reducing the incidence of hospital-acquired S. aureus infections.
Antibiotics are medications that can kill or prevent the growth of bacteria and they are frequently prescribed for the treatment of staph infections, including those caused by MRSA. There are many different types of antibiotics and each works in a different way and produces different side-effects. Broad-spectrum antibiotics are effective against many different kinds of bacteria, whereas narrow-spectrum antibiotics target specific microbes.
Depending on the type of antibiotic, treatment can be administered orally, topically or intravenously (IV). When the appropriate antibiotic is prescribed, relatively rapid improvement in the symptoms can occur. However, misdiagnosis and improper use of antibiotics can affect the success of treatment. For skin infections, a wound or tissue culture should be collected in order to guide therapeutic decisions made by doctors regarding the choice of antibiotics. In an effort to promptly again control of the infection, broad-spectrum antibiotics may be prescribed initially by your doctor and adjusted later once confirmatory laboratory reports become available. Factors that your doctor will consider before selecting an antibiotic include type, location and severity of the infection, pregnancy, drug sensitivities, or other health concerns.
Antibiotics used to treat staph infections include:
- Sulfa drugs (antibacterial sulfonamides)
Antibiotics used to treat MRSA include:
- Combination sulfamethoxazole and trimethoprim
Resistant strains of staph bacteria have largely emerged due to the misuse and overuse of antibiotics for many years. Consequently, the effectiveness of available antibiotics is diminishing.
Of increasing concern is the multiple antibiotic resistance shown by staphylococcal bacteria and their ability to produce beta-lactamase, which is an enzyme made by certain strains that inactivate many antibiotics. A common way for bacteria to develop resistance to an antibiotic is when patients stop taking the medication too early, which allows some stronger bacteria (those with a higher tolerance to the antibiotic due to mutation or trading genes with other bacteria) to multiply and gradually acquire resistance.
Bacteria can also gain resistance when antibiotics are given to patients who do not need them to begin with, or because they are not given or taken at the right dose or for the required length of time. Antibiotics are only needed to treat infections and illnesses that are caused by bacteria. Because colds and flu's are caused by viruses, antibiotic therapy is ineffective against these illnesses. Taking antibiotics unnecessarily has led to the growth of several strains of common bacteria that are now antibiotic resistant, such as MRSA.
Individuals can increase their risk of getting MRSA if:
- antibiotics are overused
- antibiotics are taken without a prescription
- directions for use are not followed, such as stopping the treatment too early or missing doses
The use of a washcloth wetted with hot water and placed over a boil or abscess can promote the drainage of pus. The application of warm compresses may be done repeatedly over several days. Topical antimicrobial medications are commonly used with the warm compress to treat localized staph infections involving the skin.
Incision and Drainage
An infected skin nodule containing pus may require drainage through a cut into the lining of the abscess, which will allow the pus to escape, reduce pain, and promote healing. The procedure involves preparation of the infected area with a topical antiseptic, followed by puncturing or cutting the wound with a sterile instrument to release the pressure and build-up of pus. Although incision and drainage is considered a minor surgical procedure, it must be performed by a doctor due to the increased risk of spreading the staph bacteria to other parts of the body, internally into the blood stream, or contaminate other people or inanimate surfaces from improper handling of used equipment or supplies.
Topical Antimicrobial Agents
Creams and ointments containing antimicrobial agents are commonly used to treat skin infections caused by staph bacteria and MRSA. Topical antimicrobials include:
- Can cause skin sensitivity
- Evidence of MRSA resistance
- Avoid use if breastfeeding
- Owing to their ability to kill harmful bacteria, topical antibacterial agents can also disrupt the balance of helpful bacteria that normally live on healthy skin, which serve to protect the body from infection. Furthermore, the use of these medications can increase the chance of re-infection by causing skin dryness and cracking (allowing staph bacteria to enter) or permitting conditions that encourage fungal growth due to the reduction of competing microorganisms.
An antimicrobial agent (e.g., chlorhexidine) or disinfectant (diluted bleach) can be added to bath water as complementary therapy for treating recurrent staph or MRSA skin infections; however, these treatments can potentially worsen the condition of your skin if done improperly. Therefore, antimicrobial baths should only be taken if they are recommended by your doctor and strict adherence to instructions and bathing frequency/duration is required.