Cellulitis is a common bacterial skin infection that affects the deeper layers of the skin and the subcutaneous tissues. It typically occurs when bacteria, most often Streptococcus or Staphylococcus species, enter through a break in the skin, such as a cut, scrape, or insect bite.

Symptoms include redness, swelling, warmth, pain in the affected area, and sometimes fever or chills. Without treatment, cellulitis can spread and lead to serious complications like abscess formation or infection of deeper tissues. Prompt medical attention is essential, and treatment usually involves antibiotics and proper wound care.

Causes of Cellulitis

Cellulitis occurs when bacteria enter the skin through a break or weak point, leading to infection. The primary causes include:

1. Bacterial Infection

The most common bacteria causing cellulitis are:

• Streptococcus pyogenes: Often associated with rapid-spreading infections
• Staphylococcus aureus: Sometimes includes strains like MRSA (methicillin-resistant Staphylococcus aureus), which are more resistant to antibiotics

2. Skin Injuries

Any disruption of the skin barrier can allow bacteria to enter, such as:

• Cuts, scrapes, or abrasions
• Insect or animal bites
• Surgical wounds

3. Pre-existing Skin Conditions

Conditions that damage or weaken the skin increase the risk of cellulitis, including:

• Eczema or psoriasis
• Athlete’s foot
• Ulcers or pressure sores

4. Medical Devices or Procedures

Devices like catheters, intravenous lines, or recent surgeries can introduce bacteria under the skin.

5. Underlying Health Conditions

Certain factors increase susceptibility to cellulitis, such as:

• Diabetes: Poor circulation and higher risk of skin injuries
• Weakened immune system: Due to conditions like HIV, chemotherapy, or steroid use
• Lymphedema: Fluid buildup in tissues can make the skin more prone to infections

Understanding these causes can help prevent cellulitis by taking precautions like maintaining good hygiene, caring for wounds properly, and managing underlying health conditions effectively.

Symptoms of Cellulitis

These are the 7 main symptoms.

1. Skin Redness and Swelling

The affected area of skin often appears red, swollen, and inflamed. The redness may spread over time, and the skin can feel tight and tender to the touch.

2. Pain and Tenderness

Pain is a common symptom, ranging from mild discomfort to significant tenderness. The area may also feel warm or hot compared to surrounding skin.

3. Skin Changes

In some cases, the skin may develop blisters, pus-filled bumps, or crusty patches. These changes can indicate a more severe infection or the formation of an abscess.

4. Systemic Symptoms

If the infection becomes severe or spreads, systemic symptoms such as fever, chills, fatigue, or malaise may occur. Lymph nodes near the infected area might also swell and become tender.

5. Rapid Progression

Cellulitis can worsen quickly if not treated, with redness and swelling spreading to larger areas. This requires immediate medical attention to prevent complications.

Recognising these symptoms early and seeking prompt medical care is crucial to effectively treating cellulitis and avoiding serious health risks.

When to See a Doctor for Cellulitis

You should seek medical attention for cellulitis if:

Symptoms Worsen Rapidly

If the redness, swelling, or pain spreads quickly or intensifies, it may indicate that the infection is progressing and requires immediate care.

Systemic Symptoms Appear

Fever, chills, sweating, or a general feeling of illness (malaise) accompanying the skin infection are signs that the infection might be spreading to other parts of the body.

Swollen Lymph Nodes

If you notice swollen or tender lymph nodes near the affected area, it can suggest the infection is advancing.

No Improvement with Initial Treatment

If symptoms do not improve within 24–48 hours after starting prescribed antibiotics, follow up with your doctor.

High-Risk Individuals

If you have a weakened immune system, diabetes, or circulation problems, cellulitis can become severe more quickly, so seek care as soon as symptoms develop.

Signs of Serious Complications

Severe symptoms like numbness, darkened skin, or red streaks radiating from the affected area could indicate a more dangerous infection or complications like sepsis.

Prompt medical care is essential to prevent complications and ensure effective treatment of cellulitis.

Treatment for Cellulitis

Treating cellulitis typically involves a combination of medical interventions and self-care measures:

Antibiotics

• Oral Antibiotics: Most cases of cellulitis are treated with a prescribed course of oral antibiotics, usually for 5–14 days. Common options include penicillins, cephalosporins, or clindamycin.
• Intravenous (IV) Antibiotics: For severe infections or when oral antibiotics are ineffective, hospitalisation and IV antibiotics may be required.

Wound Care

• Clean the affected area gently with mild soap and water.
• Cover open wounds or blisters with sterile bandages to prevent further infection.

Pain and Inflammation Management

• Over-the-counter pain relievers like ibuprofen or acetaminophen can help reduce pain and swelling.
• Elevate the affected limb to minimise swelling and improve circulation.

Addressing Underlying Causes

• Treat conditions like athlete’s foot, eczema, or ulcers that may have contributed to the infection.
• Manage chronic conditions like diabetes to improve overall healing and reduce recurrence risks.

Severe or Recurrent Cases

• In cases of recurring cellulitis, preventive antibiotics may be considered.
• Seek immediate medical attention if symptoms worsen or complications like abscesses develop.

Adhering to prescribed treatment and monitoring symptoms closely ensures effective recovery and reduces the risk of complications.