Methicillin-resistant Staphylococcus aureus, or MRSA, is a specific type of staph bacteria. It is distinguished by its resistance to methicillin and other common antibiotics, which makes it more difficult to treat. These bacteria, sometimes referred to as “superbugs,” have developed defenses against once-effective antibiotics. While many staph bacteria live on the skin without causing issues, MRSA can lead to infections if it enters the body through a cut. Though most of these infections are not severe, some can become life-threatening.
Initial Signs and Symptoms of an Infection
An early MRSA skin infection typically starts as a bump on the skin that may be mistaken for a pimple, insect bite, or spider bite. The affected area often appears as a swollen, red, and painful lump that is warm to the touch. These initial bumps can rapidly progress into deep, painful abscesses or boils that are filled with pus or other fluid.
The appearance of these symptoms is a direct result of the body’s inflammatory response to the bacterial invasion. As MRSA multiplies within the skin tissues, it releases toxins that damage cells and trigger the immune system to send white blood cells to the area. This influx of immune cells and cellular debris creates the pus that fills the abscess. The redness and warmth are caused by increased blood flow to the infected site.
The texture of the lump can also be an indicator; it may feel hard under the skin before it softens and fills with pus. In some instances, the infection may manifest as fluid-filled blisters rather than a single boil. A feature to watch for is the rapid development and worsening of the sore, as a MRSA lesion often grows in size and becomes more painful over a short period.
How MRSA Spreads
MRSA is primarily transmitted through direct physical contact with an infected person’s wound or through contact with contaminated personal items. This can occur through shared items like towels, razors, bandages, or athletic equipment. The bacteria can survive on surfaces for extended periods, facilitating its transfer. Once on the skin, it can enter the body through a minor scrape or cut.
A distinction is often made between two main environments where MRSA is acquired. Hospital-associated MRSA (HA-MRSA) occurs in individuals who have been in hospitals or other healthcare settings, like nursing homes. These infections are often linked to invasive procedures such as surgeries, the insertion of intravenous lines, or artificial joints. In these environments, healthcare workers can spread the bacteria if they have unclean hands.
Community-associated MRSA (CA-MRSA) refers to infections that occur in healthy individuals outside of traditional healthcare settings. This form often begins as a skin boil and spreads through skin-to-skin contact, making it more common in places like schools, military barracks, and gyms. Crowded living conditions and participation in contact sports are recognized risk factors for CA-MRSA transmission.
When to Seek Medical Attention
It is important to consult a healthcare provider if a skin sore or boil becomes unusually painful, shows signs of rapid growth, or is accompanied by a fever. These symptoms suggest the infection may be more serious than a common boil and requires professional evaluation. A doctor will assess the sore and ask how it developed.
To confirm a diagnosis of MRSA, a physician will likely take a culture from the wound. This involves using a sterile swab to collect a sample of pus or fluid from the infected area. The sample is then sent to a laboratory to identify the specific bacteria and determine which antibiotics will be effective against it.
Individuals should never attempt to drain a suspected MRSA abscess on their own. Squeezing or lancing the boil at home can push the bacteria deeper into the tissues, worsening the infection. It can also spread the bacteria to other parts of the skin or to other people. Proper drainage must be performed by a medical professional in a sterile environment.
Complications of an Untreated Infection
If a MRSA skin infection goes untreated, the bacteria can penetrate deeper than the skin and enter the bloodstream. This progression can lead to systemic infections that are much more difficult to manage and can become life-threatening.
Once in the bloodstream, MRSA can travel throughout the body and establish infections in various organs. The bacteria can cause dangerous conditions, including:
- Pneumonia if they settle in the lungs
- Osteomyelitis if they infect the bones
- Infections in surgical wounds and joints
- Infections in the heart valves