Skin infections & Quinolones -3
Types of Skin Infections -Cont.
  • Erysipelas
  • Erysipelas is a superficial infection of the skin, which typically involves the lymphatic system. Erysipelas is also known as St. Anthony's Fire, an accurate description of the intensity of this rash. Erysipelas was a feared disease in pre-antibiotic days, especially in infants.

Cause of Erysipelas
Erysipelas is most often caused by a specific Streptococcus bacteria known as Group A Streptococcus. In a few cases, it can be caused by other types of Streptococcus or Staphylococcus bacteria.
Some cases of erysipelas have an inciting wound such as trauma, an abrasion, or some other break in the skin that precede the fiery infection. However, in most cases, no break in the skin can be found.

Appearance of Erysipelas
Erysipelas was previously found mainly on the face. However, now it is seen most commonly on the lower extremities. Erysipelas tends to occur in areas where the lymphatic system is obstructed. A cluster of symptoms typically precede the appearance of the rash by 4 to 48 hours. These symptoms include fever, chills, fatigue, anorexia, and vomiting. The rash then quickly appears as a bright red, hot, swollen, shiny patch that has clearly defined borders. The consistency of the rash is similar to an orange peel, also known as "peau d'orange".

Diagnosis of Erysipelas
  • Erysipelas is diagnosed mainly by the appearance of the rash.
  • Blood tests and skin biopsies generally do not help make the diagnosis.
  • In the past, saline solution was injected into the edge of the rash, aspirated back out, and cultured for bacteria. This method of diagnosis is not used anymore because bacteria were not found in the majority of cases.
    If the preceding symptoms such as fever and fatigue are significant enough, sometimes blood is drawn and cultured for bacteria to rule out sepsis.

Treatment of Erysipelas
Erysipelas is treated with antibiotics. A variety of antibiotics can be used including penicillin, dicloxacillin, cephalosporin, quinolones e.g. ofloxacin. Most cases of erysipelas can be treated with oral antibiotics.
However, cases of sepsis, or infections that do not improve with oral antibiotics require IV antibiotics administered in the hospital.
some people with recurrent infections must be treated daily with low-dose antibiotics as a prevention of further infections.

  • Folliculitis
  • Folliculitis is an infection that is localized to the hair follicle. A folliculitis looks like small, yellow pustules that are confined to the hair follicle.
Factors that can lead to the development of a folliculitis include:
  • Trauma
  • Chronic friction
  • Occlusive clothing
  • Occlusive chemicals
  • Excessive sweating
  • Exposure to water

Hot Tub Folliculitis

  • Hot Tub Folliculitis
  • A special case of folliculitis that is not caused by S. aureus is hot tub folliculitis.
    This self-limited infection is caused by Pseudomonas aeruginosa contracted from hot tubs, whirlpools, and pools with inadequate chlorine levels.

Hot Tub Folliculitis Causes:
Picture of folliculitis on the leg Hot tub folliculitis is an infection of the hair follicles caused by the bacteria Pseudomonas aeruginosa. This bacteria is commonly found in contaminated whirlpools, hot tubs, water slides, physiotherapy pools, or even loofah sponges.
Children tend to get hot tub folliculitis more often, probably because they stay in the water longer. The rash consists of several small 0.5 - 3 cm red papules or wheals with a central pustule
The rash is not spread by personal contact with infected lesions.

Hot Tub Folliculitis Treatment:
Most cases of hot tub folliculitis resolve on their own and don't require specific treatment.
If needed the following treatments may be effective:
  • Vinegar compresses applied for 20 minutes two to four times a day
  • Silver sulfadiazine cream (Silvadene) applied two times a day
  • Oral antibiotics such as Ofloxacin are only needed in widespread or resistant cases.

Hot Tub Folliculitis Prevention:
Showering after contact with contaminated water does not prevent infection.

The following measures should be considered when maintaining facilities that may be prone to water contamination:
  • Frequent monitoring of disinfectant levels
  • Frequent changing of water
  • Continuous water filtration to eliminate dead skin
  • furuncle
  • A furuncle is an infection of the pilosebaceous unit, therefore is more extensive than a folliculitis because the infection also involves the sebaceous gland.
    A furuncle frequently occurs on the neck, face, armpits, and buttocks. It begins as a small, tender, red nodule that becomes painful and fluctuant. Frequently, pus will spontaneously drain, and often the furuncle will resolve on its own.
Factors that contribute to the development of furuncles include:
  • Obesity
  • Diabetes
  • Blood disorders
  • Taking oral steroid medications


  • Carbuncle
  • A carbuncle can simply be defined as an multiple furuncles grouped together.
    A carbuncle usually involves the deeper layers of the skin - the subcutaneous fat. It looks like a large, red nodule that is hot and may have visible layers of pus just beneath the surface of the skin.

Treatment of Folliculitis, Furuncles, and Carbuncles
Mild cases of folliculitis and small furuncles may heal on their own with good hygiene and wound care.
More extensive furuncles and all carbuncles need to be treated with antibiotics such as dicloxacillin or cephalexin.

If pus or induration are present, in addition to antibiotics, a procedure called
incision and drainage'It is a minor surgical procedures to release pus or pressure built up under the skin, such as from an abscess, boil, or infected paranasal sinus. It is performed by treating the area with an antiseptic, such as iodine based solution, and then making a small incision to puncture the skin using a sterile instrument such as a sharp needle, a pointed scalpel or a lancet. This allows the pus fluid to escape by draining out through the incision.'
 (I & D) should be performed to drain the pus and allow the lesion to heal from the inside out.