Common Types of Bacterial Skin Infections

Question 1

Folliculitis

Answer 1

Infection of the hair follicles. Small, erythematous, often puritic lesions. Local therapy is typically sufficient treatment.

Question 2

Furuncles and carbuncles

Answer 2

Usually develop from folliculitis. Carbuncles involve deeper tissues and may have systemic symptoms but rarely involve bacteremia. Antibiotic therapy and sometimes surgery are needed.

Question 3

Impetigo

Answer 3

superficial infection involving the epidermis usually due to group A streptococcus infection. Presents as a purulent discharge with crusting and is highly contagious.

Question 4

Erysipelas

Answer 4

Acute inflammation of the dermis involving lymphatic vessels. Usually caused by group A strep. Fever and leukocytosis may occur. Butterfly wing rash on face.

Question 5

Cellulitis

Answer 5

Involves all layers of skin to the subcutaneous tissue. Causes fever and leukocytosis and sometimes bacteremia. Group A strep and Staphylococcus aureus most common.

Question 6

Abscess

Answer 6

Localized collection of purulent material (pus), formation is caused by host defenses trying to wall off the infection.

Question 7

Gangrene

Answer 7

Advanced stage of cellulitis that has lead to significant tissue necrosis and gas in the soft tissues. Typical organisms are streptococci, mixed infection with anaerobes, and clostridial infection (classic gas gangrene).

Question 8

Necrotizing fasciitis

Answer 8

Rare, but life-threatening infection of the subcutaneous tissues. Commonly caused by group A strep.

Question 9

Arthropod-borne infections

Answer 9

Common and often have multisystem involvement. Rocky mountain spotted fever RMSF is the most sever of the tick-borne infections (30% mortality). Lyme disease is also common.