Skin Infections

dermsoc5
Jun 6, 2024
2 min read

Skin infections can be caused by bacteria, viruses and fungi. There are a lot of different skin infection types, but this post will focus on the following topics:

Cellulitis, Impetigo
Necrotising Fasciitis
Staphylococcal Scalded Skin Syndrome.

Cellulitis

Aetiology

A spreading bacterial infection in the deeper skin layer, caused by Strep pyogenes or Staph aureus
More common in diabetics and older people
A form of superficial cellulitis called Erysipelas, is caused by Strep pyogenes

Clinical presentation (1)

Swelling of hands, feet, legs or eyes
Erythema
Pain or tenderness
Blisters may appear
Fever
Nausea and vomiting
Rigors

Figure 1 – picture of orbital cellulitis, a severe infection that can cause reduced vision or painful extraocular movements. (2)

Investigations

Clinical diagnosis
Blood cultures and swabs

Management

Oral flucloxacillin
IV flucloxacillin

Impetigo

Figure 2 – Impetigo around the mouth and nose, quite common areas to be affected. (3)

Aetiology

Very infectious, caused by Staph aureus or Strep pyogenes. Impetigo can be spread through close contact or sharing items
Typically affects children
Bullous impetigo is a type of this condition which causes big fluid-filled blisters

Clinical presentation

Itchy red sores -> honey-coloured golden clusters
These patches can grow larger and become painful
Usually affecting the face, hands and feet but can spread to other body parts

Investigations

Clinical diagnosis and history
Bacterial swab (gram positive stain)

Management

Avoid contact with other people until 2 days after using antibiotics, or until the patches have crusted over
Good hand hygiene and wash sheets / towels at high temperatures (4)

Fusidic acid
Oral flucloxacillin / Clarithromycin for more severe cases

Necrotising Fasciitis (NF)

Figure 3 – Necrotising fasciitis on the right lower leg. (5)

Aetiology

Known as the “flesh-eating disease, this is a medical emergency!
Causes necrosis of the soft tissue and fascia
There are 2 types of NF (polymicrobial vs monomicrobial)
The most common bacteria linked with NF is Group A streptococcus

Clinical presentation (6)

Disproportionate pain
Oedema
Erythema
Fever
Tachycardia
Confusion
Black or purple blotches

Investigations

Blood cultures
Gram stain
Imaging – CT scan

Management

Immediate admission to hospital
Surgical debridement to remove necrotic tissue
High dose of IV antibiotics
Oxygen and fluids may be necessary

Staphylococcal Scalded Skin Syndrome (SSSS)

Figure 4 – SSSS on a child’s lower back and buttocks, showing erythematous and peeling skin. (7)

Aetiology

A rare skin disorder that is caused by Staph aureus, which secretes toxins and leads to peeling skin.
More common in neonates and kids under five, due to underdeveloped antibodies which protect against the toxins.8

Clinical presentation