Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
The majority of cases begin with an existing infection, most frequently on an extremity or in a wound. The initial infection can be from almost any cause
(for example, cuts on the skin, puncture wounds, surgical incisions, or insect bites). Instead of healing, the infected site can show erythema (redness) and swelling. The site may be very sensitive to pain, even past the area of erythema. At the same time, patients often experience fever and chills. Early symptoms resemble those of cellulitis, but progressive skin changes such as skin ulceration, bullae (thin-walled fluid-filled blisters) formation, necrotic eschars (black scabs), gas formation in the tissues, and fluid draining from the site can occur rapidly as the infection progresses. Some patients can become septic (meaning the infection has spread to the bloodstream and throughout the body) before the skin changes are recognized, especially when necrotizing fasciitis begins in deep facial planes. Type 1 often occurs after trauma or surgery and may form little or undetectable amounts of gas.
Type 2 usually occurs after more simple skin trauma (cuts, abrasions, and insect bites) and infects more superficial facial planes with almost no gas formation. Type 3 usually occurs after trauma or after wounds become contaminated with dirt that contains
Clostridium spp, which produce gas in tissues (gangrene) and necrotic eschars. However, symptoms for
types 1-3 are not definitive, and symptoms vary widely which is why some investigators prefer to define the individual patients' disease by the organism(s) isolated from the patient rather than assigning a
type label.
One set of patients that is being recognized with a more specific set of symptoms and health history are those infected with
Vibrio vulnificus. The organisms occur in the warmer waters in the U.S. (Gulf of Mexico and southern coastal states) and elsewhere in the world with similar water conditions. Either ingesting the organisms or getting
Vibrio vulnificus from contaminated seawater into skin abrasions or cuts can cause necrotizing fasciitis. The majority of those affected are either immunosuppressed or have chronic liver problems (for example, alcoholic liver disease, hepatitis, or cirrhosis). Bullae formation and rapid progression of the disease (within hours) on the extremities are hallmarks of
Vibrio vulnificus wound infections. Even though this infection is caused by a single type of bacteria, some investigators classify it as a variant of
type 1 necrotizing fasciitis.
Necrotizing enterocolitis (also termed NEC; necrosis of gastrointestinal tissue) occurs mainly in premature or sick infants and may be another variant of necrotizing fasciitis. Although investigators suggest that bacterial infection causes this disease, there is no definitive data to prove this and others attribute the disease to a permeable gut tissue. A few individuals think the necrotizing enterocolitis is due to a "leaky gut syndrome," but this concept is not widely accepted by the medical community.
MRSA (methicillin resistant Staphylococcus aureus) bacteria causes skin infections with the following signs and symptoms: cellulitis, abscesses, carbuncles, impetigo, styes, and boils. Normal skin tissue doesn't usually allow MRSA infection to develop. Individuals with depressed immune systems and people with cuts, abrasions, or chronic skin disease are more susceptible to MRSA infection.
Cellulitis is an acute spreading bacterial infection below the surface of the skin characterized by redness, warmth, inflammation, and pain. The most common cause of cellulitis is the bacteria Staph (Staphylococcus aureus).
Although a fever technically is any body temperature above the normal of 98.6 degrees F. (37 degrees C.), in practice a person is usually not considered to have a significant fever until the temperature is above 100.4 degrees F (38 degrees C.). Fever is part of the body's own disease-fighting arsenal: rising body temperatures apparently are capable of killing off many disease- producing organisms.
Sepsis (blood poisoning) is a potentially deadly infection with signs and symptoms that include elevated heart rate, low or high temperature, rapid breathing and/or a white blood cell count that is too high or too low and has more than 10% band cells. Most cases of sepsis are caused by bacterial infections, and some cases are caused by fungal infections. Treatment requires hospitalization, IV antibiotics, and therapy to treat any organ dysfunction.
Cuts, scrapes, and puncture wounds are common, and most people will experience one of these in their lifetime. Evaluating the injury, and thoroughly cleaning the injury is important. Some injuries should be evaluated by a doctor, and a tetanus shot may be necessary. Treatment will depend upon the severity of the injury.
Gangrene may result when blood flow to a tissue is lost or not adequate to keep the tissue alive. There are two types of gangrene: wet and dry. All cases of wet gangrene are infected by bacteria. Most cases of dry gangrene are not infected. If wet gangrene goes untreated, the patient may die of sepsis and die within hours or days. Dry gangrene usually doesn't cause the patient to die. Symptoms of dry gangrene include numbness, discoloration, and mummification of the affected tissue. Wet gangrene symptoms include swelling, pain, pus, bad smell, and black appearance of the affected tissue. Treatment depends upon the type of gangrene and how much tissue is compromised by the gangrene.
Group A streptococcal infections are caused by group A streptococcus, a bacteria that causes a variety of health problems, including strep throat, impetigo, cellulitis, erysipelas, and scarlet fever. There are more than 10 million group A strep infections each year.
Cellulite is caused by fat deposits that distort connective tissues under the skin, resulting in a dimpled appearance of the skin. Gender, skin thickness, heredity, and the amount and distribution of body fat all influence the presence and visibility of cellulite.
Bug bites and stings have been known to transmit insect-borne illnesses such as West Nile virus, Rocky Mountain spotted fever, and Lyme disease. Though most reactions to insect bites and stings are mild, some reactions may be life-threatening. Preventing bug bites and stings with insect repellant, wearing the proper protective attire, and not wearing heavily scented perfumes when in grassy, wooded, and brushy areas is key.
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