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  • Writer's pictureDr. Ndidi Ufondu, DPM

Cellulitis of the Foot

What is Cellulitis?

Cellulitis refers to an acute, rapidly progressing bacterial infection of the deeper layers of the skin and the tissues directly beneath. The infection leads to inflammation, causing the skin to become red, painful, warm and swollen. The borders of the affected area are generally not well-defined.

Cellulitis on the legs and feet is most often caused by streptococcus or staphylococcus bacteria entering through small cracks or openings in the skin. This may occur after an injury like a blister, ulcer, laceration, fungal infection or insect bite that compromises the protective skin barrier. Cellulitis can also arise following a surgical procedure. The bacteria then multiply, inflaming and infecting the surrounding tissues.

Signs and Symptoms

Patients with cellulitis often experience:

  • A red rash that expands rapidly over hours or days

  • Tenderness, warmth and swelling in the infected region

  • Poorly demarcated borders of the inflamed skin

  • Pain and tightness as the swelling expands

  • Fever, chills, fatigue, and flu-like illness

On the foot and lower leg, cellulitis frequently arises at sites of trauma like blisters, cuts, or ulcers. It may initially appear as red streaks tracking away from the wound as the infection spreads through the lymphatic system. Overlying skin may peel and weep fluid. Patients often cannot bear weight on the affected limb.

When to Seek Urgent Podiatry Care

While most cases of lower limb cellulitis resolve with appropriate oral antibiotic treatment, severe or rapidly progressive infections require emergency care.

Seek urgent podiatry or ER treatment if you experience:

  • Rapidly spreading rash and swelling

  • High fever, shaking chills

  • Dizziness, confusion

  • Severe pain or difficulty walking

  • Skin blistering or peeling

  • Red streaking

Rapid care helps prevent the infection from invading deeper into muscle and bone tissue. IV antibiotics are administered to halt the infection’s progression and support recovery.

Podiatrist Examination and Diagnosis

During the appointment, the podiatrist will:

  • Take a medical history – ask about risk factors, onset of symptoms, pain levels, previous wounds/injuries.

  • Examine the foot and leg – evaluate the appearance, borders, swelling, skin integrity and sensation. Palpate for tenderness and warmth.

  • Assess range of motion and ability to bear weight.

  • Check for lymph node swelling which may indicate spread through the lymphatic system.

  • Laboratory tests including complete blood count, cultures, and blood work to assess for underlying conditions like diabetes or immunodeficiency.

  • Potentially order imaging like ultrasound or MRI to assess for deeper tissue invasion if severe.

Differential Diagnosis

The podiatrist will perform a differential diagnosis to distinguish cellulitis from other conditions causing similar skin redness and swelling:

  • Insect bites or contact dermatitis cause localized, itchy welts.

  • Deep vein thrombosis presents with unilateral calf swelling, pain, warmth and vein distension.

  • Gout leads to acute onset of a hot, extremely tender joint with overlying shiny, red skin.

  • Necrotizing fasciitis is a rapidly progressing soft tissue infection causing severe systemic illness. The infection penetrates deep through multiple tissue layers.

Treatment of Cellulitis

Outpatient Care

For mild non-spreading cases, podiatrists typically prescribe:

  • Oral antibiotics to fight the bacterial infection based on lab culture results – examples are cephalexin, amoxicillin-clavulanate, clindamycin. A 10-14 day course is standard.

  • NSAID medications like ibuprofen to reduce inflammation, pain and fever.

  • Elevation of the affected leg to minimize swelling.

  • Saline or antibiotic soaks and sterile dressing changes to the wound site.

  • Over-the-counter topical antibiotic ointments after soaks/showers.

  • Follow up monitoring to ensure the infection is responding appropriately to oral antibiotics.

Inpatient Treatment

For severe or rapidly progressive cellulitis, hospitalization is required for:

  • IV antibiotic therapy to halt the infection – vancomycin, piperacillin-tazobactam, daptomycin.

  • Blood tests to identify the bacteria and its antibiotic susceptibilities. Cultures guide appropriate antibiotic selection.

  • Surgical intervention is sometimes necessary to open and drain infected tissues or abscesses, especially on the foot where pus can pool in the dense deep tissue layers. This helps the infection resolve.

  • Monitoring for progression of redness, swelling, fever, blood pressure, and lab markers.

Preventing Recurrence

To reduce recurrence after the cellulitis resolves, podiatrists instruct patients to:

  • Closely monitor the site of infection for new wounds, blisters or injuries. Promptly cleanse and cover minor wounds.

  • Moisturize daily to prevent cracked, dry skin vulnerable to bacteria entering.

  • Wear protective footwear like sturdy shoes and socks. Avoid going barefoot.

  • Treat any fungal infections like athlete’s foot.

  • Carefully trim nails to prevent ingrown toenails and injury.

  • Optimize glucose control if diabetic. High blood sugars impair wound healing.

  • Compressive stockings help prevent swelling and skin breakdown.

  • Return promptly if symptoms recur for reevaluation.

With appropriate diagnosis and urgent treatment, most cases of cellulitis can be successfully cured. Podiatrists play a key role in resolving these common foot infections and guiding preventive care. Maintaining intact, healthy skin integrity helps stave off recurrence.

Key Takeaways:

  • Cellulitis is an acute bacterial infection of the skin and underlying tissues marked by expanding redness, swelling, warmth and pain.

  • On the foot and leg, the infection often enters through cracks or wounds in the skin. It can rapidly spread and become serious if severe.

  • Urgent care is required for high fever, severe pain, blistering, red streaking or large areas of swelling to prevent deeper tissue infection.

  • Podiatrists diagnose cellulitis through physical examination of the foot, review of symptoms, and laboratory testing.

  • Treatment consists of antibiotic therapy – oral for mild cases or intravenous for severe infections. Surgical drainage may be needed.

  • Preventing dry, cracked skin and promptly treating wounds helps prevent recurrent infections after recovery.


Q: Is cellulitis contagious?

A: No, cellulitis itself is not contagious. However the bacteria causing it, like streptococcus and staphylococcus, can spread to other people through contact with infected wounds or secretions.

Q: How long does it take for cellulitis to go away?

A: With appropriate antibiotics, the symptoms of pain, redness and swelling should start improving within 1-2 days, but it may take 7-14 days for the infection to fully resolve.

Q: Can cellulitis recur after treatment?

A: Yes, it is possible to experience recurrent episodes of cellulitis, especially if the predisposing risk factors like chronic wounds, edema or cracked skin persist. Preventive foot care reduces recurrence.

Q: When does cellulitis require hospitalization?

A: Severe cases featuring intense pain, high fevers, rapid swelling, or signs the infection is invading deeper tissues often necessitate hospitalization for close monitoring and intravenous antibiotics.

Q: Are there any complications of untreated cellulitis?

A: Yes, without proper treatment cellulitis can invade tissues beneath the skin, leading to serious complications like abscesses, necrotizing fasciitis, sepsis, or permanent tissue damage. Prompt medical care prevents complications.


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