Cellulitis
This is an infection of the deeper parts of the skin involving the deeper dermis as well as the subcutaneous tissues. This is most commonly caused by streptococcus but occasionally staph aureus. In children it is most commonly caused by staph aureus although H Influenza may also be causal. In the healthy individual, cellulitis requires a break in the skin. Alcoholism, diabetes, poor circulation as well as fungal infections on the feet allowing bacteria to enter may be factors that allow entry. There are usually fevers and chills. The skin is red, swollen and tender. This is not well defined as in Erysipelas which is more superficial. When this is severe there may be blistering as well as some pustules present. It may be associated with a red line extending along the lymph channels and there may be tenderness and swelling of the lymph nodes. A rare complication will include inflammation in the kidneys called acute glomeruli nephritis.
Treatment: In all cases systemic antibiotics will be required. Most of the time oral antibiotics are required even for the milder cases.
Impetigo
This is a common superficial skin infection which is very contagious and is seen mostly in children. It can be either blistering or non-blistering. It is most commonly caused by staphylococcal infection although streptococcus pyogenes is sometimes a cause. It is spread easily by direct contact. It is more common in warm climates with high humidity and is often associated with mild skin trauma. The bullous form of impetigo is caused by staph aureus, usually Phage II Type 71. This causes blistering. This most commonly occurs in young infants or neonates and may be associated with fever. It starts as a small blister particularly on the face, trunk or buttocks. The blister will slowly enlarge to rupture leaving shiny skin which then becomes eroded. There is often a surrounding scale. The non-blistering or non-bullous form, which makes up the majority of infections, is usually caused by staph aureus but occasionally strep pyogenes. This commonly occurs at sites of minor trauma to the skin such as insect bites, reactions, abrasions, cuts, and hand burns. It usually starts with small reddish patches measuring about 2-4mm. They evolve to form small pustules or tiny blisters. These become easily crusted with a typical yellow or honey crust. It spreads by direct extension. It is most commonly seen on the face around the nose, mouth and also the extremities. The diagnosis is usually clear by examination of the skin. If left untreated this may resolve itself.
Treatment: The application of topical antibiotics such as mupirocin cream or ointment (Bactroban) is very effective. Fusidic acid (Fucidin) is also used. If the infection is more extensive oral antibiotics such as Cloxacillin or Cephalexin are used as well as those in the erythromycin family.
Ecthyma
This is a deeper form of impetigo. It occurs in the epidermis as well as in the dermis, producing a superficial ulcer that becomes secondarily crusted. It usually occurs secondary to trauma and is most commonly seen with poor hygiene. The lesions will often last for many weeks becoming essentially ulcerated and may even scar the skin. Secondary cellulitis and osteomyelitis are very uncommon developments.
Treatment: Oral antibiotics such as Cloxacillin or Keflex are often required
Erysipelas
This is an infection involving the deeper parts of the skin. The dermis a subcutaneous tissue is usually involved. There is involvement in the lymph drainage system.This is caused by streptococcus pyogenes. This is seen in the young as well as in the aged. It is also seen in those who are sick and with chronic swelling of the limbs and chronic ulcers. It is more common in the summer. The face is most often involved although the lower legs can also be involved. There is an abrupt onset of fever and a feeling of being unwell. There is redness which is well defined particularly on the cheeks. The skin feels hot, tense and swollen. It is often very well defined. There is tenderness on pressing the skin. The local lymph glands may be swollen and tender. Usually the diagnosis can be made by examining the skin.
Treatment: Penicillin is usually required for this. Erythromycin will be used in those allergic to Penicillin.
Scarlet Fever
This is a disease of childhood. It is caused by a Group A beta hemolytic strep. The majority of cases occur under the age of ten. It is most common in the fall and winter. The bacteria produces a toxin that causes the skin effects. The onset of the disease is usually sudden starting with a sore throat and viral like symptoms such as headaches, fatigue, chills and high fever. Abdominal pain and vomiting can occur. The rash starts one or two days after this with redness most often in the neck, chest and armpits. The rest of the body quickly becomes involved. Small red papules develop. This has been described as sunburn with goose bumps. It feels rough like sandpaper. There are streaks of bruises particularly in the folds of the body. The cheeks are red although the skin is white around the mouth. After a week to ten days there is peeling of the skin most marked on the hands and feet. This may last for up to one month and sometimes longer.
Treatment: Treatment is oral antibiotics such as erythromycin.
Necrotizing Fasciitis
This is a rapidly extending infection with destruction of tissue in the fat and muscles. It can be fatal. It involves redness, tenderness, and swelling similar to that seen in cellulitis. The patient is extremely sick.
Treatment: Oral antibiotics are required. Surgical intervention is necessary with a fasciotomy: opening up of the tissue and removal of the dead tissue.
Streptococcal Toxic Shock Syndrome
This is a rapidly expanding condition that may be fatal. It produces fever, shock and organ failure associated with soft tissue infection. It most commonly occurs in healthy people, young adults to midlife. There is usually some disruption of the skin protective mechanism allowing the introduction of Streptococcus. Initially there is significant pain, often in the extremities. There is swelling, tenderness, and redness that occurs. This may be associated with blistering. The infection sometimes becomes deeper affecting muscles and fascia. The shock and organ failure may develop with two to three days. The organism involved is usually a Group A streptococcus.
Treatment: General support for the internal organs is required.Oral antibiotics such as Clindamycin will be used. This aggressive intensive care is required.
