Cellulitis Pathophysiology, Etiology, Contagious Bacteria and MRSA

Cellulitis is the term used to describe a common infection of superficial and underlying skin layers. Infection is usually acute, without involving death of fat tissue. If that happens, it is referred to as necrotizing fasciitis.

Bacteria strains are the common causes of cellulitis. But not all bacteria cause this condition. In fact, treatment sometimes depends on the bacteria strain being dealt with. Most cellulitis infections, however, respond to commonly prescribed antibiotics. See what is the best antibiotic for cellulitis for details.

Cellulitis pathophysiology and how it develops

Cellulitis pathophysiology is not very complicated. Many bacteria can be found on the skin at any given time. As they are, they rarely are problematic. This is because conditions on the skin do not favor bacterial growth and spread. For that to happen, requirements such as moisture, nutrition and warmth must be present. As it happens, the soft tissues below the epidermis provide all three requirements.

It is through injuries and discontinuities in skin that pathogens reach soft tissues. There, they rapidly divide. Soon, the body is able to detect this abnormal activity. The immediate reaction is to set off inflammation. Immune cells are sent to the affected area in large numbers. Many activities have to inevitably take place almost concurrently as bacteria divide and immune cells fight them off. As a result, the affected area swells, reddens, becomes tender and feels hot. Sometimes, immune cells are able to fight off all invading bacteria. If not, infection reaches adjacent areas and the blood. It is from then on that cellulitis is considered dangerous.

It is not obvious that cellulitis will develop around a recently injured area. Insect bites/stings, animal/human bites and foreign objects such as piercing can also introduce cellulitis infection. Some patients develop cellulitis after surgery.

In some cases, infection can result from metastasis in a local infection. This is common in cellulitis ear infection where it spreads to the eye. Distant metastasis is not common, however. This is where an infection like pneumonia acts as a source of bacteria for an infection elsewhere in the body, such as cellulitis in the scrotum. The more familiar case is when infection in the upper respiratory tract causes orbital cellulitis symptoms.

Cellulitis etiology; what bacteria cause cellulitis?

What causes cellulitis infection? Many types of bacteria are identifiable in the etiology of cellulitis. In people not diagnosed with any disease or condition that may compromise their immune systems, the common cellulitis bacteria type that causes infection is streptococci group A and staphylococcus aureus.

When cellulitis develops due to complications in the lymphatic system caused by an infection, groups G, C and B streptococci are usually responsible. These bacteria enter the lymphatic system as a complication of untreated infection. There, they may damage lymphatic vessels or block lymph fluid from circulating.

The results are that lymphatic fluid accumulates in some areas of the body, mostly the lower legs, arms, head and chest. Without the lymphatic system, infections will rarely go away without medical treatment.

Children are susceptible to Haemophilus influenza type B and S pneumoniae bacteria. These are the causes of facial cellulitis common in children. Incidence rate has dropped in the recent times due to availability of vaccines. Another common infection in children is streptococcus cellulitis. This affects infants before their immune systems are strong enough to fight off bacteria, usually before age of six months. Cellulitis on stomach or umbilical cellulitis can for example develop in an infant. Medical treatment is very necessary in this case. This is because infections in infants can trigger widespread inflammation in the body, causing systematic organ failure.

Pneumonia bacteria can cause severe cellulitis, which produces widespread spread symptoms even in its initial stages. Most cases are reported in diabetic individuals where cellulitis develops in the lower legs or arms. Symptoms may also mimic those of lupus, where systematic inflammation occurs mostly in head and neck areas. This form of cellulitis is quite dangerous and spreads rapidly.

MRSA or methicillin-resistant Staphylococcus aureus is a bacteria type responsible for severe cellulitis, which is particularly hard to treat.

Cellulitis bacteria can be picked up in hospitals such as after surgery. When this happens, crepitus or cracking sounds may originate in affected area.

There are some factors and conditions that make some people more susceptible to cellulitis infection than others.

Patients undergoing cancer treatment sometimes get several of their lymph nodes removed. This plus other treatment methods often weaken their immune systems. As a result, bacterial infections like cellulitis often develop and even become chronic. The process of immune systems being weakened by diseases is not uncommon. It is also seen in HIV, diabetes, liver disease and kidney disease patients.

Not having a strong immune system makes one susceptible to some gram negative bacteria types not commonly diagnosed in cellulitis infections. In fact, other pathogens such as fungi and viruses can cause cellulitis in such individuals. This is especially after a herpes or athlete’s foot positive diagnosis.

MRSA cellulitis infection

Most of us have used antibiotics, whether in oral, topical or intravenous forms. Not many people understand how these medications work however. It is not that everyone is supposed to know how they work. The problem is that total ignorance predisposes people to infections caused by bacteria which are very hard to treat.

Success of antibiotics is based on the fact that one antibiotic can kill a range of bacteria types. In recent days, it has been noted that some bacteria have developed mechanisms to avoid being killed with antibiotics. What this means is that we may be heading back to the era before penicillin, where a simple cut could easily leave you in the grave. A good example of a simple infection that may soon become untreatable is MRSA cellulitis.

MRSA is not new to scientists. For the last 50 years, it has been cultured and only appeared in hospitals. Patients could catch it when hospitalized but rarely in the outside world. This has drastically changed in recent years. Cases of cellulitis being caused by MRSA are on the rise.

The problem with MRSA is that it doesn’t respond to commonly prescribed antibiotics. This means that infection may continue to spread and wreck havoc even after medical treatment. Even worse, cultures that may help doctors identify the bacteria often are with disappointing results. It is for this reason that patients are advised to check with their doctor should symptoms of cellulitis not improve in 48 hours after first dosage. MRSA cellulitis may require IV antibiotics. This means that patients will be hospitalized with and probably require cellulitis nursing diagnosis.

Some MRSA cellulitis infections are community-acquired. The bacteria can also be picked in hospitals such as during dialysis or surgery but especially with long-term IV medications use.

Complications of cellulitis

More than 90% of all cellulitis patients recover without complications. This is as long as treatment is done timely and in the right fashion. In view of failure with that, complications of cellulitis may occur. These include:

  • Abscess – an abscess is what a large boil could be. It is a pocket of pus formed deep in the skin. Abscess is a common sign of MRSA cellulitis infection. Surgery is required for treatment. Without facial cellulitis treatment, an abscess in the eye can cause total blindness.
  • Lymphangitis – lymphangitis is when lymphatic vessels become inflamed after they are exposed to bacteria. This is usually seen as red streaks that develop from the site of local infection towards the heart. Nearby lymph nodes may swell and become painful. If not treated, lymphangitis can lead to lymphedema and consequently symptoms of cellulitis in leg.
  • Osteomyelitis – osteomyelitis is the clinical term for bone infection. It occurs when infection reaches deep enough to invade bones. Pain is usually present accompanied by swelling and redness.
  • Sepsis – sepsis is a deadly complication of infections that can cause systematic organ failure in a matter of minutes. When bacteria release toxins into the blood, they trigger production of chemicals meant to fight the bacteria and stop blood poisoning. The chemicals can, however, trigger systematic inflammation all over the body, sending patients into septic shock if not treated immediately.
  • Meningitis – the reason as to why eye cellulitis is sometimes thought as contagious is because it can easily spread to the brain and spinal cord. This is not to mention the fact that most eye cellulitis cases are complications of untreated upper respiratory infections. Once bacterial infection reaches the brain and spinal cord, membranes surrounding these organs swell. What results is a series of actions that are life threatening.
  • Gangrene – gangrene as a complication of cellulitis is best seen in case of scrotal cellulitis. Fluid accumulates between two skin tissues, making it impossible for blood to be supplied in one of the tissues. Without blood circulating in an organ, cells and tissues die.
  • Necrotizing fasciitis – this is a condition caused by “flesh eating bacteria.” The bacteria do not necessarily eat flesh as the name suggests. What they do is produce toxins that poison adjacent fat tissue.

Is cellulitis contagious?

Cellulitis develops in soft tissues. Above these tissues is epidermis, the uppermost layer of skin. Epidermis keeps cellulitis bacteria from being passed around during direct skin to skin contact. For this reason, cellulitis is not contagious.

It should be noted that cellulitis does spread to adjacent areas and circulatory system even though not contagious. Cellulitis home treatment options such as use of topical agents, use of home remedies and keeping wounds clean may help reduce rate of spread.

MRSA has been noted to be notorious in more than one way. Some experts believe that sharing personal hygiene items can transfer the bacteria. The common manner in which MRSA becomes contagious is by being shared during IV drugs use. This is especially true in people with compromised immune systems.