Cellulitis is a non-necrotizing skin infection of the dermis and subcutaneous tissue caused by bacteria such as Streptococcus pyogenes and Staphylococcus aureus. Risk factors include skin breaks, comorbidities like diabetes, and immunosuppression. Patients present with red, swollen, painful skin that is warm to touch. Treatment involves antibiotics to treat the infection along with supportive measures like elevation. More severe cases require intravenous antibiotics in the hospital. Complications can include abscesses, necrotizing fasciitis, and sepsis if not properly treated.

1. CELLULITIS
Dr. Mungai
Medical Officer

2. 1) Definition
• Cellulitis is commonly used to indicate a non
necrotizing inflammation of the dermis and
hypodermis related to acute infection that does not
involve the fascia or muscles
• Characterized by signs of inflammation.
1) Pain
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3. 2) Epidemiology
• Because cellulitis is not a reportable disease,
the exact prevalence is uncertain.
• In a large epidemiological hospital-based
study on skin, soft tissue, bone, and joint
infections, 37.3% patients were identified as
having cellulitis.

4. 3) Risk Factors
• Race
No racial predilection has been noted.
• Sex
No predilection for either sex is usually reported,
although a higher incidence among males has
been reported in some studies.
• Age
Under 5 yrs and above 45 years of age are highly
predisposed.

5. • Comorbidities
- Factors associated with an increased risk of
infection are the presence of concurrent
illness eg, congestive heart failure, morbid
obesity, hypoalbuminemia, renal insufficiency,
diabetes mellitus, hypertension
- Immunosuppression is a major factor in our
setting
- Intravenous drug abusers are also vulnerable.

6. • The presence of foreign bodies, including
indwelling intravenous catheters, external
orthopedic pins, and other surgical devices,
predisposes to infection in the local area.

7. Causative agents
• In immunocompetent adults, cellulitis is usually
due to Streptococcus pyogenes and
Staphylococcus aureus.
• Patients who are immunocompromised with may
develop cellulitis due to infection with other
organisms, including gram-negative bacilli (eg,
Pseudomonas, Proteus, Serratia, Enterobacter,
Citrobacter) anaerobes.
• Escherichia coli may be responsible for cellulitis in
patients with nephrotic syndrome

8. • Cellulitis occurring around surgical wounds less
than 24 hours postoperatively may result from
GABHS (Group A beta hemolytic streptococcus)
or Clostridium perfringens infection.
• Clostridium perfringens produces gas, which may
be appreciated on examination as crepitus.
• Recurrent cellulitis due to streptococci may be
observed in patients with chronic lymphedema
• Streptococcal infections are also common in
injection drug users.

9. 4) Pathogenesis
• Cellulitis usually follows a break in the skin,
such as a fissure, cut, laceration, insect bite, or
puncture wound.
• Organisms on the skin and its appendages
gain entrance to the dermis and multiply to
cause cellulitis.
• The vast majority of cases are caused by
Streptococcus pyogenes or Staphylococcus
aureus.

10. • Cellulitis may rarely result from the metastatic
seeding of an organism from a distant focus of
infection, especially in immunocompromised
individuals.
• The incubation period is somewhat organism
dependent.
• Postoperative cellulitis at the surgical site due to
group A beta-hemolytic streptococci may
develop rather rapidly.
• On the other hand, cellulitis due to
staphylococci usually is delayed in onset.

11. 5) Clinical presentation
HISTORY
• The patient may or may not relate an episode
of trauma that has preceded their symptoms
• If the patient recalls an episode of trauma, the
clinician should ask about circumstances
surrounding the incident that may elicit clues
to a particular etiology.

12. • The past medical history should focus on the
presence of comorbid conditions that
increase the risk for cellulitis, the most
common of which include diabetes mellitus,
HIV infection/AIDS, chronic kidney disease,
and chronic liver disease.
• The surgical history may include a recent
surgery that resulted in wound infection.

15. PHYSICAL EXAMINATION
• Involved sites are red, warm, swollen, and
painful.
• The borders are not elevated or sharply
demarcated.
• Lymphangitis, regional lymphadenopathy, or both
may be present.
• Malaise, chills, fever, and systemic toxicity may
occur.
• In severe cases, patients may develop septic
shock.
• Local suppuration may follow if therapy is
delayed.
• Overlying skin may develop areas of necrosis.

16. • Cellulitis is majorly a clinical diagnosis
• The most common site is the leg

17. LABORATORY WORK UP
• Complete blood Count - CBC
• C-REACTIVE PEPTIDE – CRP
• Erythrocyte sedimentation rate – ESR
• Random Blood Sugars – RBS
• HIV test
• Urinalysis
• Urea Electrolyte and Creatinine - UECs
• Blood Cultures

18. • Skin biopsy is unnecessary, unless a
nonbacterial etiology is suspected or in
immunocompromised individuals

19. IMAGING STUDIES
• Ultrasonography may be helpful in evaluating
suppuration at the site and as an aid in
guiding needle aspiration.
• It can also help rule out deep vein thrombosis
mimicking cellulitis.
• CT scanning or MRI may be helpful to rule out
any underlying fasciitis or osteomyelitis, if
suspected.

20. 6) Differential Diagnosis
• Osteomyelitis
• Necrotising fasciitis
• Thrombophlebitis
• Deep Venous Thrombosis
• Angioedema
10 others ???????

21. 7) Management
• Patients with mild cases of cellulitis may be
treated in an outpatient setting.
• Oral agents with activity against staphylococci
and streptococci (eg, dicloxacillin or
flucloxacillin,, clindamycin, cotrimoxazole,
amoxicillin/clavulanate) are usually effective
for the treatment of cellulitis in
immunocompetent hosts.

22. • Severely ill patients and those unresponsive to
standard oral antibiotic therapy should be
treated with intravenous antibiotics in the
hospital.
• This is also recommended in immunosuppressed
individuals, in those with facial cellulitis, and in
any patients with a clinically significant
concurrent condition, including lymphedema,
malignancy, and cardiac, hepatic, or renal
conditions

23. Supportive care
• Elevating the affected limb
• Cold compresses
• Analgesic medications
• Antipyretic medications
• Hematinic medications
Management of the medical and surgical
cormobidities is important.

24. • Urgent consultation with a surgeon should be
sought in the setting of;
i. crepitus,
ii. circumferential cellulitis,
iii. necrotic-appearing skin,
iv. rapidly evolving cellulitis,
v. pain disproportional to physical examination
findings,
vi. severe pain on passive movement,
vii. or other clinical concern for necrotizing fasciitis

25. • Circumferential cellulitis may result in
compartment syndrome.
• Surgical decompression, i,.e, fasciotomy may
be necessary.
• Cellulitis associated with an abscess requires
surgical drainage of the source of infection for
adequate treatment.

26. 8) Complications
• Abscess formations
• Necrotizing fasciitis
• Osteomyelitis
• Chronic ulcer
• Septicaemia
• Death
• NB; CATEGORIZE INTO IMMEDIATE, EARLY,
INTERMIDIATE AND LONG TERM COMPLICATIONS

27. • Cellulitis generally is a localized infection.
Most patients treated appropriately recover
completely.
• Mortality is rare (5%) but may occur in
neglected cases or when cellulitis is due to
highly virulent organisms (eg, P aeruginosa).

28. THANK YOU