Bacterial Cellulitis: Symptoms, Causes, Diagnosis, Treatment and Complications


It is an infection of the skin and the tissues beneath it. Unlike impetigo, which is a very superficial skin infection, bacterial cellulitis is an infection that also affects the deeper layers of the skin: the dermis and the subcutaneous tissue.

The main bacteria responsible for bacterial cellulitis are Streptococcus and Staphylococcus, the same bacteria that can cause impetigo and other diseases.

Sometimes, other bacteria (for example, Hemophilus influenzae, Pneumococcus, and Clostridium) can also cause bacterial cellulitis.

Bacterial cellulitis is quite common and affects people of all races and ages. Men and women seem to be equally affected.

Although it can occur in people of any age, it is more common in middle-aged and older adults. Bacterial cellulitis is not contagious.

If it is not treated, the infection can spread and endanger life; you should get medical help immediately if you experience the symptoms of bacterial cellulitis.



Symptoms may include:

  • Pain and sensitivity in the affected area.
  • Redness or inflammation of the skin
  • A skin sore or rash that appears and proliferates.
  • A tight, shiny, and swollen appearance of the skin.
  • Heat sensation in the affected area.
  • A central location that has an abscess with pus formation.
  • Fever.

Some common symptoms of a more serious bacterial cellulitis infection are:

  • Cold.
  • A feeling of discomfort
  • Fatigue.
  • Dizziness.
  • Daze.
  • Muscle pains.
  • Hot skin
  • Perspiration.

Symptoms such as the following could indicate that bacterial cellulitis is spreading:

  • Drowsiness.
  • Lethargy.
  • Red stripes on the skin.
  • You should contact your doctor immediately if any of these symptoms occur.

Causes and risk factors of Bacterial Cellulitis

It occurs when bacteria enter through a crack or cut in the skin, commonly caused by Staphylococcus and Streptococcus bacteria.

Cutaneous lesions such as cuts, insect bites, or surgical incisions are common sites of infection. Certain factors also increase your risk of developing bacterial cellulitis.

Common risk factors include:

  • A weakened immune system.
  • Skin conditions that cause breaks in the skin, such as eczema and athlete’s foot.
  • Intravenous drug use.
  • Diabetes.
  • History of bacterial cellulitis.


Your doctor can usually diagnose bacterial cellulitis at first sight but will perform a physical examination to determine the extent of your condition. This test could reveal:

  • Swelling of the skin
  • Redness and heat of the affected area.
  • Swollen glands

Depending on the severity of your symptoms, your doctor may want to control the affected area for a few days to see if the redness or swelling spreads.

In some cases, your doctor may perform a blood test or a culture of the wound to detect the presence of bacteria.


Your doctor will usually prescribe a 10 to 21-day regimen of oral antibiotics to treat your bacterial cellulitis.

The duration of your treatment with oral antibiotics will depend on the severity of your condition. Even if the symptoms improve in a few days, taking all the prescribed medications is essential to ensure proper treatment.

While taking antibiotics, check your condition to see if the symptoms improve. In most cases, the symptoms will improve or disappear in a few days.

In some cases, analgesics are prescribed. It will help if you rest until your symptoms improve.

Contact your doctor immediately if you do not respond to treatment within three days of starting a round of antibiotics, if your symptoms worsen or if you have a fever.

Bacterial cellulitis must disappear within seven to 10 days after the start of antibiotics. More extended treatment may be necessary if your infection is severe.

This can happen if you have a chronic illness or your immune system is not working correctly.

People with certain pre-existing medical conditions and risk factors may need to stay in the hospital for observation during treatment. Your doctor can advise hospitalization if you:

  • It has a high temperature.
  • It presents high blood pressure.
  • You have an infection that does not get better with antibiotics.
  • It has a compromised immune system due to other diseases.
  • It requires intravenous antibiotics when oral antibiotics do not work.

Possible complications of bacterial cellulitis

Sometimes, bacterial cellulitis can spread throughout the body, entering the lymph nodes and blood flow. In rare cases, it can penetrate more deep layers of tissue. The possible complications that may occur are:

  • An infection in the blood.
  • A bone infection.
  • Inflammation of the lymphatic vessels.
  • Tissue death or gangrene.


If you have a break in the skin, clean it immediately and apply an antibiotic ointment regularly.

Cover the wound with a bandage and change it daily until a scab forms. Look at your damages for redness, drainage, or pain. These symptoms can indicate an infection.

People with poor circulation or who have pre-existing conditions that put them at risk for bacterial cellulitis should take additional precautions, including:

  • Keep the skin moist to prevent cracking.
  • Treat superficial skin infections promptly, such as athlete’s foot.
  • Wear protective equipment when working or playing.
  • Inspect the feet daily for signs of injury or infection.