Cellulitis resident survival guide

Cellulitis Resident Survival Guide Microchapters
Overview
Causes
Diagnosis
Treatment
Dos
Don'ts

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mydah Sajid, MD[2]

Synonyms and keywords:: Bacterial skin infection, Local skin infection.
To read the cellulitis microchapter click here.

Overview

Cellulitis is the inflammation of deeper layers of the skin including the dermis and subcutaneous tissue. It is mostly due to a bacterial infection. The bacteria usually invades the deeper layers after breaching the skin barrier. Common bacteria such as streptococcus pyogenes, staphylococcus aureus, haemophilus influenza type B, clostridium, streptococcus pneumoniae and neisseria meningitidis usually involve the lower limbs. It presents clinically with signs of inflammation such as redness, swelling, warmth and pain. Risk factors for cellulitis include a weakened immune system, diabetes, lymphatic obstruction, and varicose veins. It is recommended to first rule out deep vein thrombosis (DVT) with compression doppler ultrasound of the limbs and d-dimer level. Elevated levels of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and leukocytosis could be detected. It is required to check systemic signs of infection. It is treated conservatively with oral antibiotics in uncomplicated cases. Parenteral antibiotics are administered in patients with systematic symptoms and progressive lesions. Incision and drainage are done if discrete abscesses are present.

Causes

Life-Threatening Causes

No known life-threatening causes are included.

Common Causes

The cellulitis is bacterial in origin and caused by the invasion of bacteria through the skin barrier. The common causes are listed below.:

• Streptococcus pyogenes
• Staphylococcus aureus
• Haemophilus influenza type B
• Clostridium
• Streptococcus pneumoniae
• Neisseria meningitidis

Diagnosis

Shown below is an algorithm summarizing the diagnosis of cellulitis according to the Infectious Diseases Society of America guidelines.

Patients present with the following symptoms: Erythema Edema Warmth Swollen regional lymph nodes Involvement of one limb

Perform compression doppler ultrasound of the limb and D-dimer level

Positive

Negative

Deep vein thrombosis (DVT) is likely.

DVT unlikely. High clinical suspicion for cellulitis

Assess levels of inflammatory markers

Raised erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and leukocytosis

Does the patient have any of the following signs of systemic or rapidly progressive infection? Body temperature >101.5 degrees Fahrenheit, chills, headache, and fatigue Signs of sepsis such as hypotension and heart rate > 100bpm Patient develops rapidly progressive symptoms like bullae, vesicles, petechia and crepitus Patient with low immunity (such as infants and elderly patients)

Perform the following tests: Debridement of the wound with the culture of the specimen Blood culture Radiographic tests to evaluate deep tissue infection

Treatment

Shown below is an algorithm summarizing the treatment of cellulitis.

Does the cellulitis present with purulent discharge?

Yes

No

Are there any of the following present? Systemic toxicity (fever, hypotension, and tachycardia) Presence of an indwelling device (pacemaker, vascular graft) Patient is on extremes of age Major comorbid conditions

Incise and drain any discrete abscess: Delay oral antibiotic therapy Monitor patient for spontaneous resolution. If response is inadequate then initiate oral antibiotic therapy

Yes

No

Initiate intravenous antibiotic therapy. The coverage of the microorganisms is determined by: Oral or peri-rectal ulcers Pressure ulcer with draining abscess Necrosis of overlying skin

Initiate Oral antibiotic therapy. The coverage of the microorganisms is determined by: Oral or peri-rectal ulcers Pressure ulcer with draining abscess Necrosis of overlying skin

Yes

No

Yes

No

Initiate antibiotics that cover both MRSA and gram negative rods. To cover MRSA: Vancomycin or Daptomycin Plus one of the following to cover for gram negative rods: Ampicillin-Sulbactam Piperacillin-Tazobactam Ceftriaxone plus metronidazole Levofloxacin plus metronidazole

Infection most likely due to MRSA. Initiate Vancomycin or Daptomycin

Incision and drainage of discrete abscesses. Send drained specimen for culture and susceptibility. Start wide coverage empirical antibiotic covering MRSA, gram negative rods, anaerobes, and gram-positive organisms. Regimens include: Trimethoprim-Sulfamethoxazole plus amoxicillin-clavulanate Doxycycline plus levofloxacin plus metronidazole Minocycline plus amoxicillin-clavulanate

Assess patient's risk for infective endocarditis

Yes

No

Initiate empirical antibiotics coverage for MRSA and beta-hemolytic streptococci. Regimens include trimethoprim-sulfamethoxazole or doxycycline plus amoxicillin or minocycline plus amoxicillin. Incise and drain the abscess an hour after administration of the first dose of oral antibiotic. Send the specimen for culture and sensitivity and start antibiotic accordingly after the results.

Incise and drain the discrete abscess Send the specimen for culture and sensitivity Initiate empirical antibiotics for MRSA. Regimens include trimethoprim-sulfamethoxazole or doxycycline or minocycline

Dos

• Supportive care including elevation of the limb and adequate moisturizing of the cellulitis site should be done. The elevation of the limb promotes venous and lymphatic drainage from the site. Moisturize the affected site with emollients and moisturizers. It will hydrate the skin and prevent breakouts.
• Physicians should prescribe antibiotics for patients according to their body weight. Obese or lymphedema patients can be given a lower dose than their body weight, which results in inadequate response and failure of the treatment.
• The duration of antibiotic treatment is variable and depends upon the clinical improvement of the cellulitis. Mostly, there is significant improvement within a day or two after the initiation of the antibiotics. The patient should receive the treatment for five days. The antibiotic course is given for two weeks in patients with systematic symptoms, low immunity, and rapidly progressive cellulitis.

Don'ts

• Suppressive antibiotic therapy is administered to patients with three to four episodes of cellulitis per year with predisposing factors that can not be alleviated. Suppressive antibiotic therapy is directed against beta-hemolytic streptococci and staphylococci infection. Suppressive antibiotic therapy is not beneficial in patients with greater than three episodes of cellulitis in a year, chronic edema, and obesity.
• Physicians should not perform incision and drainage for discrete abscesses in patients with high susceptibility of bacterial endocarditis without prior administration of the antibiotic. 2 grams of oral amoxicillin should be given to the patient an hour before performing incision and drainage of the infected site.