Cellulitis

2331

A common bacterial infection of the skin and subcutaneous tissue.

Occurs mostly in the legs and is associated with healthcare costs, and adverse health outcomes.

Can be caused by normal skin flora or by exogenous bacteria.

The typical symptoms of cellulitis is an area which is red, hot, and tender.

The skin break does not need to 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 normally cause no actual infection while on the skin’s outer surface.

Dental infections account for approximately eighty percent of cases of cellulitis of the submandibular space (Ludwig’s angina).

Mixed infections, due to both aerobes and anaerobes, are commonly associated with the cellulitis of Ludwig’s angina.

Typically this includes alpha-hemolytic streptococci, staphylococci and bacteroides groups.

Predisposing conditions for cellulitis include insect or spider bite, blistering, animal bite, tattoos, surgery, athlete’s foot, dry skin, eczema, injecting drugs, pregnancy, diabetes and obesity, which can affect circulation, as well as burns and boils,hidradenitis suppurativa.

Once below the skin, the bacteria can spread rapidly, entering the lymph nodes and the bloodstream and spreading throughout the body.

The infection can spread to the deep layer of tissue called the fascial lining.

Recurrence is coming with up to 47% of patients having a recurrent episode within three years.

Penicillin prophylaxis is effective in preventing recurrence of cellulitis, although the protective effect diminishes progressively once the antibiotic agent is discontinued.

Necrotizing fasciitis, also called by the media “flesh-eating bacteria”, is an example of a deep-layer infection.

Chronic edema is a risk factor for cellulitis of the leg and for recurrent cellulitis.

Chronic edema Refers to swelling that lasts for three months or longer.

The principal cause of edema may be increased capillary filtration or failure of lymphatic drainage, which may be a result of lymphedema, venous hypertension, immobility, obesity, and heart failure.

In patients with chronic edema of the leg and cellulitis, compression therapy result in a lower incidence of recurrence of cellulitis than conservative treatment. (Webb E).

The elderly and those with immunodeficiency are especially vulnerable to contracting cellulitis.

Diabetics are more susceptible than the general population as hyperglycemia allows bacteria to grow more rapidly in the affected tissue, and facilitates rapid progression if the infection enters the bloodstream.

Immunosuppressive drugs, and other illnesses or infections that impair the immune system, also increase risk of cellulitis.

Lymphedema, and chronic venous insufficiency increases risk.

Cellulitis more prevalent among concentrated populations such as military installations, college dormitories, and nursing homes.

It is most commonly a clinical diagnosis.

Cultures do not always identify the causative organism.

Often occurs where the skin has previously been disrupted.

Skin on the face or lower legs is most commonly affected but can occur on any part of the body.

Treatment is with antibiotics, and recovery periods last from 48 hours to six months.

Erysipelas refers to a more superficial infection of the dermis and upper subcutaneous layer that presents clinically with a well-defined edge.

Erysipelas and cellulitis often coexist.

Cellulitis and cutaneous abscess are the second most common infections leading to hospitalization, with nearly 600,000 annual admissions in the US.

Predominant pathogens are aerobic gram positive organisms.

Almost always caused by S aureus or streptococcus pyogenes group A.

Lower extremity cellulitis incidence is about 199 cases per 100,000 person years and is comparable to venous thromboembolism, hip trauma due to moderate trauma, and new onset kidney stones, which are approximately 117, 115, and 102 cases per 100,000 persons years, respectively.

Blood cultures usually are positive only if the patient develops generalized sepsis.

Conditions that may resemble cellulitis include:deep vein thrombosis and stasis dermatitis, Lyme disease.

When it occurs with acne conglobata, hidradenitis suppurativa, and pilonidal cysts, the syndrome is referred to as the follicular occlusion triad or tetrad.

Treatment consists of resting the affected area, debridement of necrotic tissue, and antibiotics.

Antibiotics, such as derivatives of penicillin or other types of antibiotics that are effective against the responsible bacteria, are used to treat cellulitis.

Sometimes treatment requires the administration of intravenous antibiotics in a hospital setting.

Treatment for more than 7-14 days is not necessary.