Cellulitis is an acute, non-contagious inflammation of the connective tissue of the skin, resulting from Staphylococcus, Streptococcus, or other bacterial infection. It is a skin infection that also involves areas of tissue just below the skin surface. Often cellulitis begins in an area of broken skin, like a cut or scratch, but it may also start in areas of intact skin, especially in diabetics or who are taking medicines that affect the immune system.
Causes
- Streptococcus pyogenes (group A B-hemolytic streptococcus)
- Aerobic Gram-negative bacilli (eg, Escherichia coli, Pseudomonas aeruginosa)
Open wounds
- Staphylococcus aureus, aerobic Gram-negative bacilli
Animal bite
- Pasteurella multocida from dogs and cats Water injuries
- Freshwater caused by Aeromonas hydrophila
- Warm salt water- caused by Vibrio vulnificus.
Risk Factors
- Insect bites and stings
- Animal bite or human bite; injury or trauma with a skin wound
- History of peripheral vascular disease, diabetes, or ischemic ulcers
- Recent cardiovascular event
- Pulmonary, dental, or other procedures
- Immunosuppressive or corticosteroid medications.
Signs and Symptoms
- Localized skin redness or inflammation that increases in size as the infection spreads
- Tight, 9lossy, "stretched" appearance of the skin
- Pain or tenderness of the area
- Macule: sudden onset, usually with sharp borders
- Rapid growth within the first 24 hours
- Boils, blisters, pustules, or similar lesions
- The thin red line (along a vein) from the cellulitis toward the heart (lymphangitis)
- Warmth over the area of redness
- Fever
- Other signs of infection
- Chills
- Warm skin, sweating
- Fatigue
- Myalgias
- Malaise
- Nausea and vomiting
- Joint stiffness caused by swelling of the tissue over the joint
- Hair loss at the site of infection
DIAGNOSIS
Differential Diagnosis
- Perianal cellulitis
- Acute gout
- Fasciitis
- Thrombophlebitis
- Osteomyelitis
- Herpetic whitlow
- Cutaneous diphtheria
- Mycotic aneurysm
- Ruptured baker's cyst Pseudogout
Investigations
- CBC
- Blood culture
TREATMENT
Goal
Eliminate the source of infection and treat the condition appropriately
Non-Pharmacological Treatment
If pus or an open wound is present, immobilization and elevation of the affected area helps reduce edema and cool, wet dressings relieve local discomfort.
Pharmacological Treatment
Streptococcus pyogenes, Staphylococcus aureus
- Cephalosporins
- Quinolones
- Penicillins
- Macrolides
- Others- Vancomycin
Aminoglycoside-Treating concomitant tinea pedis, often eliminating the source of bacteria residing in the inflamed, macerated tissue, prevent recurrent leg cellulitis.
PATIENT EDUCATION
- Recommend hygiene
Complication
- Gangrene
- Sepsis, generalized infection, and shock
- Meningitis (if cellulitis is on the face)
- Lymphangitis
Prognosis
The cure is possible with 7 to 10 days of treatment. Cellulitis may be more severe if the chronic disease is present or if the person is susceptible to infection (immunosuppressed).
Complications
- Pneumonia
- Conjunctival scarring
- Penetration of the cornea can occur within 2 days in patients with untreated N gonorrhea
- Meningitis.
Prognosis
The prognosis is good. Conjunctivitis typically is self-limited and without long-term complications.