Cellulitis

Cellulitis and a Poorly Demarcated Red Border

Cellulitis is an infection of the skin with involvement of the subcutaneous tissues. It has poorly demarcated borders, in contrast to erisypelas, which does not go into subcutaneous tissues but is more superficial and has marked swelling of skin with well demarcated borders.
Cellulitis Epidemiology

Cellulitis is more common in men and affects usually the lower extremity. Extremely common in diabetics and patients with suppressed immune systems.

Cellulitis Risk Factors

1.Disruption of cutaneous barrier



Leg ulcer (diabetic or trauma), Traumatic wound, Toe-web intertrigo or fungal infections which can break the skin barrier and lead to ulcerations, Dermatoses such tinea pedis also known as Athlete's foot

2.Previous history of cellulitis

This occurs are there has been prior damage to the skin making it vulnerable to subsequent infection.

3.Venous or lymphatic damage or insufficiency

Venous insufficiency (varicose veins), Overweight (decreased venous return to heart from increased pressure from fat on veins compressing them and leading to stasis), Prior saphenectomy, Prior pelvic radiation or malignancy, Previous tibial fractures, Pregnancy, Filariasis (a parasitic disease in which your lymphatics are damaged and blocked from the parasite).
Cellulitis Microbiology

Cellulitis is usually caused my bacteria that are found on the skin, mainly beta-hemolytic streptococcus, but also Staphylococcus aureus, Pseudomonas if there is a puncture wound, and pasteurella and erysipelothrix if the wound is due to animal contact.
Cellulitis Diagnosis

Most common findings are redness, warmth and tenderness. The hallmarks of inflammation. If these are not present, start looking for something else. Cellulitis is also accompanied with lymphadenopathy and lymphangitis commonly. Abscess may be seen in severely immunocompromised patients or patients presenting with long-standing cellulitis. Systemic features are rare, unless presentation is late, but patients may have fever, chills, and myalgias.

Cultures are usually not sent, because they are often contaminated by commensal bacteria that are not the culprits. Blood and skin cultures however may be sent if there is signs of sepsis, water or animal exposure, recurrent infection, no response to treatments, risk factors for recurrence (lymphedema)


Cellulitis Prognosis

Cellulitis is overall slow to resolve and requires 10-14 days of treatment with antibiotics, usually intravenous.
Cellulitis Treatment

Treatment should be started immediately with empiric antibiotics to cover the most common cultprits, beta-hemolytic Streptococcus and Staphylococcus aureus, Ancef 1-2g IV q8h or Nafcillin 2g IV q4h. Vancomycin is used if there is a severe infection or the infection is associated with dead tissue.
Drug-Resistant Cellulitis

Linezolid, daptomycin, and tigecycline are used.

If the patient is stable, non-toxic, and able to keep their limbs elevated, with guaranteed follow-up and monitoring, then the patient may be treated as an outpatient with oral therapy, Keflex 500 mg po every 6 hours. Clindamycin if allergic to penicillin.
Cellulitis and Immunocompromised Patients

If immunocompromised, treatment is with clindamycin, ceftriaxone, and ciprofloxacin, as polymicrobil coverage is required.