Cellulitis Symptoms, Causes, and Treatment

Cellulitis is a common bacterial infection. It is usually caused by streptococci or staphylococci bacteria. and to a lesser extent by other types of bacteria.

Cellulitis primarily attacks the surface layers of the skin, though it may also affect the deeper layers. Over time, it can spread to the bloodstream and lymph nodes. According to the American Academy of Dermatology, cellulitis affects around 14.5 million Americans each year.

Commonly, cellulitis appears on the lower legs and feet, though it can be found anywhere on the extremities, torso, and neck or face. It is a painful infection, characterized by swelling that’s soft and warm to the touch. Cellulitis has a tendency to spread quickly and aggressively.

Potentially, cellulitis can be a life-threatening disease. If you suspect you might have cellulitis, schedule an appointment with your healthcare provider as soon as possible. Continue reading for more info on cellulitis symptoms, causes, and treatment.

Cellulitis Symptoms

Cellulitis primarily appears as a painful swelling. However, depending on the severity of the infection, you might also experience a wide range of other symptoms.

Primary Symptoms

The most common ones include fever, inflammation, and rashes (or sores) that spread quickly. The affected area might also be swollen, red, and glossy. It can also feel tender and painful to the touch. Also, it is not uncommon for the affected area to have an abscess with pus in the center.

Secondary Symptoms

Apart from the primary symptoms, cellulitis can also be accompanied by a slew of other secondary symptoms. The secondary symptoms affect the body as a whole. They include but are not limited to chills, lightheadedness, warm skin, shaking, overall illness and weakness, sweating, muscle pain, dizziness, and tiredness.

Advanced Symptoms

If the primary and secondary symptoms are left untreated and the infection spreads beyond skin tissue, you may experience a number of other symptoms. These may include lethargy, red streaks, drowsiness, and blistering. If you experience any of these, go to your healthcare provider right away.


If left unchecked, cellulitis can spread beyond the skin and cause some serious damage to your body. In its worst forms, it can be lethal. Most commonly, cellulitis spreads into the bloodstream and lymph system. Some of the most common complications include:

  • Septicemia. Septicemia is a bacterial blood infection that leads to sepsis. It is a serious condition that must be treated inpatient at a hospital. The infection can quickly spread to other tissue and major organs and cause them to fail. Severe sepsis can easily cause septic shock, which is often lethal.
  • Osteomyelitis. Another potential complication of cellulitis is osteomyelitis or bone infection. Bone infection can happen when the bacteria that caused cellulitis enters the bloodstream. Once it happens in one area, it can quickly spread throughout the body. The bacterium Staphylococcus aureus is the most common cause of bone infection. Fever, irritability, redness, chills, general weakness, swelling, and stiffness of the affected limb are the most common symptoms.
  • Lymphadenitis. Inflammation of the lymph node is another potential complication of untreated cellulitis. The most common sign is swollen lymph nodes. The swelling may also be accompanied by fever, sore throat, runny nose, nocturnal sweats, swelling of the limbs, and blockade of the lymphatic system. Sometimes, the hardening and growth of the lymph nodes may occur, as well.
  • Gangrene. In a nutshell, gangrene is the death of tissue. There are three main forms of gangrene – dry, wet, and gas gangrene. Bacteria can cause wet and gas gangrene, the latter of which is the realm of bacteria that cause cellulitis. The affected tissue grows moist and breaks down which results in wet gangrene. Due to the moisture, wet gangrene can spread throughout the body faster than the dry gangrene.

Causes and Risk Factors

Cellulitis can be caused by a variety of bacteria. The most common culprits include staphylococcus, streptococcus, and Staphylococcus aureus.

These and many other bacteria live on human skin and don’t generally cause much harm. However, when they enter the body, such as via cracks or cuts in the skin, cellulitis may occur. Also, insect bites, cuts, and surgical incisions are potential sites of cellulitis. The bacteria can penetrate even tiny cracks and scratches.

Commonly, a healthy immune system is strong enough to fight the bacteria off and prevent infection. But if your immune system is compromised, you run a higher risk of developing cellulitis.

The following conditions and diseases can increase the risk: HIV/AIDS, liver disease, athlete’s foot, recent surgery, diabetes, kidney disease, atopic dermatitis, lymphedema, and poor circulation. According to the American Academy of Dermatology (AAD), corticosteroid use, ongoing chemotherapy, and immunosuppressants can heighten the risk of cellulitis. The AAD also states that children, athletes, prisoners, drug addicts, soldiers, and residents of long-term care facilities are among the risk groups.

Diagnosis and Treatment

Cellulitis is obvious enough to be diagnosed on sight. Swelling, warmth, tenderness, and redness of the affected area are usually enough for the diagnosis. The attending physician would use a blood test to confirm the diagnosis.

When confirmed, doctors would prescribe antibiotics. Depending on the severity of the infection (and the strength of the patient’s immune system), the antibiotics regimen can be for 10 to 21 days. Painkillers would be made available to those experiencing a great deal of pain.

It is recommended to rest as much as possible while the symptoms last. The patient would also be advised to raise the affected part of the body above the heart level to reduce swelling.

In case the cellulitis is accompanied by high blood pressure and temperature, the patient might have to stay over. Hospitalization may also be required for those who have a weak immune system or don’t respond well to the initial antibiotics therapy.

The Takeaway

Cellulitis is a bacterial infection that’s contracted through cracked or injured skin. It is a serious infection, though it can be cured relatively easily if diagnosed in its earliest stages.

Mostly, it is caused by staphylococcus and streptococcus bacteria. Common cellulitis symptoms include swelling, pain, itching, redness, and fever.

Due to possibly fatal complications, it is of the utmost importance to see a doctor as soon as you notice the symptoms of the infection.