Cellulitis
From Wikipedia, the free encyclopedia
| Cellulitis Classification and external resources |
|
 |
|
|---|---|
| Infected left shin | |
| ICD-10 | L03. |
| ICD-9 | 682.9 |
| DiseasesDB | 29806 |
| eMedicine | med/310 emerg/88 derm/464 |
| MeSH | D002481 |
Cellulitis is a diffuse infection of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, blisters, burns, insect bites, surgical wounds, or sites of intravenous catheter insertion. Skin on the face or lower legs is most commonly affected by this infection, though cellulitis can occur on any part of the body. The mainstay of therapy remains treatment with appropriate antibiotics.
Erysipelas is the term used for a more superficial infection of the dermis and upper subcutaneous layer that presents clinically with a well defined edge. Erysipelas and cellulitis often coexist, so it is often difficult to make a distinction between the two.
Cellulitis is unrelated to cellulite, a cosmetic condition featuring dimpling of the skin.
Contents |
[edit] Causes
Cellulitis is caused by a type of bacteria entering the skin, usually by way of a cut, abrasion or break in the skin. This break need not be visible. Group A Streptococcus and Staphylococcus are the most common of these bacteria, which are part of the normal flora of the skin but cause no actual infection while on the skin's outer surface. Predisposing conditions for cellulitis include insect bite, blistering, animal bite, tattoos, pruritic skin rash, recent surgery, athlete's foot, dry skin, eczema, injecting drugs (especially subcutaneous or intramuscular injection or where an attempted IV injection "misses" or blows the vein), pregnancy, diabetes and obesity, which can affect circulation, as well as burns and boils, though there is debate as to whether minor foot lesions contribute.
The photos shown here of Cellulitis are more severe cases than what can be spotted typically at earlier stages. Usually the itch and/or rash appears but shortly after vanishes leaving only a small mark which is commonly ignored.
The appearance of the skin will help a doctor make a diagnosis. The doctor may also suggest blood tests, a wound culture or other tests to help rule out a blood clot deep in the veins of the legs. Cellulitis in the lower leg is characterized by signs and symptoms that may be similar to those of a clot occurring deep in the veins, such as warmth, pain and swelling.
This reddened skin or rash may signal a deeper, more serious infection of the inner layers of skin. Once below the skin, the bacteria can spread rapidly, entering the lymph nodes and the bloodstream and spreading throughout the body.
In rare cases, the infection can spread to the deep layer of tissue called the fascial lining. Necrotizing fasciitis, also called by the media "flesh-eating bacteria," is an example of a deep-layer infection. It represents an extreme medical emergency.
[edit] Risk factors
The elderly and those with immunodeficiency (a weakened immune system) are especially vulnerable to contracting cellulitis. Diabetics are more susceptible to cellulitis than the general population because of impairment of the immune system; they are especially prone to cellulitis in the feet because the disease causes impairment of blood circulation in the legs leading to diabetic foot/foot ulcers. Poor control of blood glucose levels allows bacteria to grow more rapidly in the affected tissue and facilitates rapid progression if the infection enters the bloodstream. Neural degeneration in diabetes means these ulcers may not be painful and thus often become infected.
Immunosuppressive drugs, HIV, and other illnesses or infections that weaken the immune system are also factors that make infection more likely. Chickenpox and shingles often result in blisters that break open, providing a gap in the skin through which bacteria can enter. Lymphedema, which causes swelling on the arms and/or legs, can also put an individual at risk.
Diseases that affect blood circulation in the legs and feet, such as chronic venous insufficiency and varicose veins, are also risk factors for cellulitis.
Cellulitis is also extremely prevalent among dense populations sharing hygiene facilities and common living quarters, such as military installations, college dormitories, and homeless shelters.
[edit] Diagnosis
Cellulitis is most often a clinical diagnosis, and local cultures do not always identify the causative organism. Blood cultures usually are positive only if the patient develops generalized sepsis. Conditions that may resemble cellulitis include deep vein thrombosis, which can be diagnosed with a compression leg ultrasound, and stasis dermatitis, which is inflammation of the skin from poor blood flow.
There have been many cases where Lyme disease has been misdiagnosed as staph- or strep-induced cellulitis. Because the characteristic bullseye rash does not always appear in patients infected with Lyme disease, the similar set of symptoms may be misdiagnosed as cellulitis. Standard treatments for cellulitis are not sufficient for curing Lyme disease. The only way to rule out Lyme disease is with a blood test, which is recommended during warm months in areas where the disease is endemic.[1]
[edit] Incubation
Cellulitis can develop in as little as 24 hours or can take days to develop.
[edit] Duration
In many cases, cellulitis takes less than a week to disappear with antibiotic therapy. However, it can take months to resolve completely in more serious cases and can result in severe debility or even death if untreated. If it is not properly treated, it may appear to improve but can resurface months or even years later.
[edit] Treatment
Treatment consists of resting the affected limb or area, cleaning the wound site if present (with debridement of dead tissue if necessary) and treatment with oral antibiotics, except in severe cases, which may require admission and intravenous (IV) therapy.[2] Flucloxacillin monotherapy (to cover staphylococcal infection) is often sufficient in mild cellulitis, but in more moderate cases or where streptococcal infection is suspected then usually combined with oral phenoxymethylpenicillin or intravenous benzylpenicillin, or ampicillin/amoxicillin (e.g. co-amoxiclav in the UK). Pain relief is also often prescribed, but excessive pain should always be considered relevant, as it is a symptom of necrotising fasciitis, which requires emergency surgical attention.
As in other maladies characterized by wounds or tissue destruction, hyperbaric oxygen treatment can be a valuable adjunctive therapy, but is not widely available.[3][4]
[edit] Prevention
Any wound should be cleaned and dressed appropriately. Changing bandages daily or when they become wet or dirty will reduce the risk of contracting cellulitis. Medical advice should be sought for any wounds that are deep or dirty and when there is concern about retained foreign bodies.
[edit] Cellulitis in horses
Horses may acquire cellulitis, usually secondary to a wound (which can be extremely small and superficial) or to a deep-tissue infection, such as an abscess or infected bone, tendon sheath, or joint.[5][6] Cellulitis from a superficial wound will usually create less lameness (grade 1-2 out of 5) than that caused by septic arthritis (grade 4-5 lameness). The horse will exhibit inflammatory edema, which is marked by hot, painful swelling. This swelling differs from stocking up in that the horse will not display symmetrical swelling in two or four legs but in only one leg. This swelling begins near the source of infection but will eventually continue down the leg. In some cases, the swelling will also travel upward. Treatment includes cleaning the wound and caring for it properly, the administration of NSAIDs, such as phenylbutazone, cold hosing, applying a sweat wrap or a poultice, and mild exercise. Veterinarians may also prescribe antibiotics. Recovery is usually quick and the prognosis is very good if the cellulitis is secondary to skin infection.
[edit] References
- ^ Nowakowski, John, et al. "Failure of Treatment with Cephalexin for Lyme Disease." Archives of Family Medicine, Vol. 9, June 2000.
- ^ Vinh DC, Embil JM (September 2007). "Severe skin and soft tissue infections and associated critical illness". Curr Infect Dis Rep 9 (5): 415–21. PMID 17880853.
- ^ Douso ML (2009). "Hyperbaric oxygen therapy as adjunctive treatment for postoperative cellulitis involving intrapelvic mesh". J Minim Invasive Gynecol 16 (2): 222–3. doi:. PMID 19249714.
- ^ Escobar SJ, Slade JB, Hunt TK, Cianci P (2005). "Adjuvant hyperbaric oxygen therapy (HBO2) for treatment of necrotizing fasciitis reduces mortality and amputation rate". Undersea Hyperb Med 32 (6): 437–43. PMID 16509286. http://archive.rubicon-foundation.org/4061. Retrieved on 2009-03-07.
- ^ Adam EN, Southwood LL (August 2006). "Surgical and traumatic wound infections, cellulitis, and myositis in horses". Vet. Clin. North Am. Equine Pract. 22 (2): 335–61, viii. doi:. PMID 16882479. http://journals.elsevierhealth.com/retrieve/pii/S0749-0739(06)00031-9. Retrieved on 2009-03-07.
- ^ Fjordbakk CT, Arroyo LG, Hewson J (February 2008). "Retrospective study of the clinical features of limb cellulitis in 63 horses". Vet. Rec. 162 (8): 233–6. PMID 18296664. http://veterinaryrecord.bvapublications.com/cgi/pmidlookup?view=long&pmid=18296664. Retrieved on 2009-03-07.
- Cellulitis Overview (with picture).
- King, Christine, BVSc, MACVSc, and Mansmann, Richard, VDM, PhD. "Equine Lameness." Equine Research, Inc. 1997. Pages 548-549.
- MFMER. 'Cellulitis'. 3 July 2002. Mayo Foundation for Medical Education and Research. 30 Oct. 2003 [1].
- NLM. 'Group A streptococcal infections'. 2002. National Library of Medicine. 30 Oct. 2003 [2].
- Pankey, George A. "Approach to rashes and infections of the skin and subcutaneous tissues." Textbook of internal medicine. 2nd ed. 2 vols. Philadelphia: J. B. Lippincott Company, 1992.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
