What is the Difference Between Cellulitis and Necrotizing Fasciitis

The key difference between cellulitis and necrotizing fasciitis is that cellulitis is a bacterial infection of inner layers of skin that specifically affects the dermis and subcutaneous fat, while necrotizing fasciitis is a bacterial infection of inner layers of skin that specifically affects subcutaneous tissue or hypodermis.

Skin and soft tissue infections (SSTIs) are due to microbial invasions of the skin. Management of these conditions is based on severity, location of the infection, and patient comorbidities. Skin and soft tissue infections include infection of the skin, subcutaneous tissue, fascia, and muscle. It encompasses a wide spectrum of clinical presentations ranging from cellulitis to necrotizing fasciitis.

CONTENTS

1. Overview and Key Difference
2. What is Cellulitis 
3. What is Necrotizing Fasciitis
4. Similarities – Cellulitis and Necrotizing Fasciitis
5. Cellulitis vs Necrotizing Fasciitis in Tabular Form
6. Summary – Cellulitis vs Necrotizing Fasciitis

What is Cellulitis?

Cellulitis is a bacterial infection of the inner layers of skin that specifically affects the dermis and subcutaneous fat. Cellulitis is a superficial skin infection. It is caused by bacteria that enter and infect tissue through breaks, cuts, and bites in the skin. Cellulitis may be associated with a subcutaneous abscess or carbuncle. Group A Streptococcus and Staphylococcus are the most common causes of cellulitis. These bacteria are on the skin as normal flora in healthy individuals.

Figure 01: Cellulitis

Typical symptoms of cellulitis include an area that is red, hot, and painful on the skin. Often, this redness turns white when pressure is applied. Severe cellulitis can cause lymphedema. Moreover, the person who suffers from this condition may have a fever and feel tired. The legs and face are the most common sites involved in cellulitis. However, it can happen in any part of the body. The risk factors include obesity, leg swelling, and old age. Furthermore, the potential complications of this condition may include abscess formation, fasciitis, and sepsis.

Cellulitis can be diagnosed through skin observation, blood cultures and ultrasonography. The treatment is typically through pain relief medications and antibiotics prescriptions such as cephalexin, amoxicillin, cloxacillin, erythromycin, or clindamycin. If an abscess is also present, surgical drainage is performed.

What is Necrotizing Fasciitis?

Necrotizing fasciitis is a bacterial infection of the inner layers of skin that specifically affects subcutaneous tissue or hypodermis. It is a severe disease with rapid onset. The symptoms usually include red or purple skin in the affected area, severe pain, fever, and vomiting. The most affected areas of the body are the limbs and perineum. The bacteria that cause this infection typically enter the body through a break in the skin, such as a cut or burn. The risk factors may be poor immune function, diabetes, cancer, obesity, intravenous drug use, alcoholism, and peripheral artery disease.

Figure 02: Necrotizing Fasciitis

This disease does not spread between people. Methicillin-resistant Staphylococcus aureus (MRSA) bacteria are involved in most cases of infections. This disease is usually treated with surgery to remove the infected tissue and intravenous antibiotics such as penicillin G, clindamycin, vancomycin, and gentamycin.

What are the Similarities Between Cellulitis and Necrotizing Fasciitis?

  • Cellulitis and necrotizing fasciitis are two types of skin and soft tissue infections.
  • Both diseases can be caused by Staphylococcus aureus and Streptococcus pyogenes.
  • The subcutaneous layer of the skin can be affected in both diseases.
  • They are treated with antibiotics.

What is the Difference Between Cellulitis and Necrotizing Fasciitis?

Cellulitis is a bacterial infection of inner layers of skin that specifically affects the dermis and subcutaneous fat, while necrotizing fasciitis is a bacterial infection of inner layers of skin that specifically affects subcutaneous tissue or hypodermis. So, this is the key difference between cellulitis and necrotizing fasciitis. Furthermore, cellulitis has a good prognosis, while necrotizing fasciitis has a poor prognosis.

The following infographic lists the differences between cellulitis and necrotizing fasciitis in tabular form for side by side comparison.

Summary – Cellulitis vs Necrotizing Fasciitis

Skin and soft tissue infections are due to microbial infections of the skin. Cellulitis and necrotizing fasciitis are two types of skin and soft tissue infections. Cellulitis affects the dermis and subcutaneous fat, while necrotizing fasciitis affects subcutaneous tissue or hypodermis. Thus, this summarizes the difference between cellulitis and necrotizing fasciitis.

Reference:

1. “Cellulitis.” Nhs Choices, NHS.
2. Holm, Gretchen. “Necrotizing Fasciitis: Causes, Symptoms, and Treatment.” Healthline, Healthline Media, 17 Sept. 2018.

Image Courtesy:

1. “Orbital cellulitis” By EdTech Stanford University (CC BY-NC-ND 2.0) via Flickr
2. “Necrotizing fasciitis caused by Vibrio Vulnificus” By Torrance HD, Cordova AC, Hoppe IC – (CC BY 2.0) via Commons Wikimedia