Scarlet Fever Bacteria

The bacteria that cause scarlet fever are called group A streptococcus -- the same bacteria that cause strep throat. These bacteria can also cause certain skin infections such as impetigo, erysipelas, and cellulitis. Health experts estimate that scarlet fever bacteria cause more than 10 million mild infections every year.

Scarlet Fever Disease

What Are the Bacteria That Cause Scarlet Fever?

Scarlet fever is an illness caused by bacteria called group A streptococcus, the same bacteria that cause strep throat.

Scarlet Fever Bacteria: Group A Streptococcus

Group A streptococcal (strep) infections are caused by group A streptococcus, a bacterium responsible for a variety of health problems. Group A streptococcus consists of one species of bacteria, Streptococcus pyogenes.

Scarlet fever bacteria are gram-positive (high in sugar and amino acids) bacteria that form chains when put into a liquid media (see Scarlet Fever Pictures). These bacteria are facultative anaerobes, meaning that they can survive with or without oxygen.

Scarlet fever bacteria produce three toxins (known as pyrogenic exotoxins), which are thought to be responsible for the symptoms of scarlet fever.

Other Group A Streptococcus Infections

Group A streptococcus is most familiar to people because it is responsible for strep throat. Group A streptococcus can also cause skin infections, such as:

Impetigo (characterized by blisters that may itch)
Erysipelas (hardened, painful skin lesions with raised borders)
Cellulitis (inflammation of connective tissue of the skin).

Health experts estimate that more than 10 million mild infections (throat and skin) are caused by group A streptococcus every year.

Group A streptococcus can also cause more serious infections, including:

Bacteremia (blood stream infections)
Toxic shock syndrome (multi-organ infection)
Necrotizing fasciitis (flesh-eating disease).

Occasionally, group A streptococcus can also cause pneumonia.