Definition and Overview
Skin infections on the legs and feet are common medical concerns that can affect people of all ages but are particularly serious in certain populations. These infections occur when bacteria, fungi, or other pathogens invade the skin through breaks in the protective barrier, such as cuts, scratches, insect bites, or existing skin conditions. The lower extremities are especially vulnerable due to their distance from the heart, which can affect circulation and healing.
The appearance of infected skin typically includes a combination of redness (erythema), swelling (edema), warmth, and pain or tenderness. The infection may start as a small area but can spread rapidly if left untreated. In legs and feet, infections are particularly concerning because of the potential for complications such as deep tissue involvement, bone infection (osteomyelitis), or systemic spread leading to sepsis.
Certain individuals face higher risks of leg and foot infections, including those with diabetes, peripheral vascular disease, lymphedema, or compromised immune systems. For these populations, even minor skin injuries can lead to serious infections. Early recognition and prompt treatment are crucial to prevent complications such as tissue death, amputation, or life-threatening systemic infections. Understanding the signs of infection and knowing when to seek medical care can make a significant difference in outcomes.
Types of Infections and Causes
Bacterial Infections
- Cellulitis: Deep skin and tissue infection
- Erysipelas: Superficial skin infection
- Impetigo: Contagious superficial infection
- Folliculitis: Hair follicle infection
- Abscess: Pus-filled pocket
- Necrotizing fasciitis: Flesh-eating disease
- MRSA: Resistant staph infection
- Diabetic foot infections: Multiple organisms
Wound and Ulcer Related
- Pressure ulcers: Bedsores
- Venous ulcers: Poor circulation
- Arterial ulcers: Inadequate blood flow
- Diabetic ulcers: Neuropathy related
- Traumatic wounds: Cuts, punctures
- Surgical site infections: Post-procedure
- Burn infections: Secondary infection
- Bite wounds: Animal or insect
Other Causes
- Thrombophlebitis: Vein inflammation
- Osteomyelitis: Bone infection
- Fungal infections: Athlete's foot spread
- Ingrown toenail: Secondary infection
- Paronychia: Nail fold infection
- Lymphangitis: Lymph vessel infection
- Eczema infection: Superinfection
- IV drug use: Injection site infections
Signs of Infection and Associated Symptoms
Local Signs
- Redness spreading outward
- Swelling and tightness
- Warmth to touch
- Pain or tenderness
- Pus or drainage
- Red streaks (lymphangitis)
- Blisters or bullae
- Skin breakdown or ulcers
Emergency Warning Signs - Seek Immediate Care
Go to the emergency room immediately for:
- Rapidly spreading redness or swelling
- Red streaks extending up the leg
- High fever (over 101°F/38.3°C) with infection
- Severe pain out of proportion to appearance
- Black or dead-looking skin
- Crepitus (crackling under skin)
- Confusion or altered mental state
- Signs of sepsis (low BP, rapid pulse)
- Exposed bone or tendon
- Foul-smelling drainage
- Diabetes with any foot infection
- Compromised immunity with infection
Risk Factors and Evaluation
Factors increasing infection risk:
High-Risk Conditions
- Diabetes: Neuropathy and poor healing
- Peripheral artery disease: Poor circulation
- Venous insufficiency: Swelling and stasis
- Lymphedema: Impaired drainage
- Immunosuppression: Medications, HIV
- Obesity: Skin fold infections
- Previous infections: Recurrence risk
- Skin conditions: Eczema, psoriasis
Treatment and Management
Medical Treatment
- Oral antibiotics (most cases)
- IV antibiotics (severe infections)
- Wound debridement
- Incision and drainage
- Hospitalization if systemic
- Vascular assessment
- Blood sugar control
- Surgery for deep infections
Supportive Care
- Elevate affected limb
- Rest and limit walking
- Keep wound clean and dry
- Change dressings as directed
- Complete antibiotic course
- Monitor for spreading
- Pain management
- Compression (if advised)
Prevention Strategies
Reduce infection risk through:
- Daily foot inspection: Especially for diabetics
- Proper wound care: Clean and cover all cuts
- Good hygiene: Regular washing and drying
- Moisturize dry skin: Prevent cracks
- Proper footwear: Avoid injuries
- Manage chronic conditions: Control diabetes, improve circulation
- Treat fungal infections: Prevent secondary bacterial infection
- Avoid going barefoot: In public areas
- Trim nails carefully: Avoid ingrown nails
- Address swelling: Compression, elevation