Clinical: Skin infections

Question 1

What are the two main presentations of Impetigo?

Answer 1

• Bullous Impetigo
• Non Bullous Impetigo

Question 2

What is the difference in the causative organisms for bullous impetigo and non bullous impetigo?

Answer 2

Bullous: Staphylococcal Epidermolytic toxin Non Bullous: Staph Aureus or Streptococcus or both

Question 3

Who does non bullous impetigo typically affect and during what time of year?

Answer 3

Young children often in late summer

Question 4

What distribution of impetigo is seen in neonates?

Answer 4

Widespread

Question 5

What are the predisposing factors for impetigo?

Answer 5

Minor skin abrasions and the existence of other skin conditions such as infestations or eczema

Question 6

What is this?

Answer 6

Impetigo

Question 7

Child presents with fever, irritability and skin tenderness. Erythema usually begins in the groin, axillae and around the mouth. Blisters and superficial lesions develop over 1-2days and can rapidly involve large areas with systemic upset. Diagnosis?

Answer 7

Staphylococcal Scalded Skin Syndrome

Question 8

What is the difference between SSSS and Toxic Epidermal Necorosis

Answer 8

SSSS: splits beneath the stratum corneum

TEN: the whole epidermis is affected

Question 9

What action should be taken in a patient with suspected SSSS?

Answer 9

Systemic antibiotics, immediate commencement of intensive support measures, rehydration, bacterial swabs should be taken from family members

Question 10

What happens following SSSS?

Answer 10

Although the acute presentation is very severe, rapid recovery and absense of scarrig are usual as the epidermal spilt is superficial

Question 11

Patient presents with fever, desquamating rash, circulatory collapse (low bp and hypotension) and multi-organ involvement…diagnosis?

Answer 11

Toxic Shock Sydrome due to Staph Aureus toxins

Question 12

What is the difference between cellulitis and erysipelas?

Answer 12

• Cellulitis is inflammation of subcutaneous tissue, due to bacterial infection. It is typically ill defined and affects the leg.
• Erysipelas is bacterial infection of the dermis and upper subcutaneous tissue. It is typically well defined and affects the face

Question 13

What is the diagnosis?

Answer 13

Cellulitis

Question 14

• Hot, painful, erythematous and oedematous
• What is the diagnosis?

Answer 14

Erysipelas

• Most affected site is the face

Question 15

Lesions with dome like, “umbilicated”, skin coloured papules with central punctum, often multiple and found at side of chest and inner arm

Answer 15

Molluscum Contagiosum

Question 16

Lesions are erythematous, annular and scaly, with well defined edge and central clearing. There may also be pustules at the active edge. Lesions are usually assymmetrical and can be single or multiple.

Answer 16

Tinea Corporis. Caused by fungal infection.

Question 17

Itchy rash between the toes with peeling, fissuring and maceration.

Answer 17

Athlete’s foot or Tinea Pedis

Question 18

What is the difference between Herpes Simplex 1 and Herpes Simplex 2, and which is more prevalent?

Answer 18

HSV-1: involves the mucocutaneous surfaces of the head and neck. More prevalent.

HSV-2 predominantly involves the genital mucosa

-There may be some overlap

Question 19

How do people become exposed to the Herpes Simplex Virus?

Answer 19

Infection is acquired by innoculation of viruses shed by an infected individual on to a mucosal surface in a susceptible person

-The virus infects sensory and autonomic neurons and establishes latent infection in the nerve ganglia. Primary infection is followed by reactivation throughout life.

Question 20

What happens following exposure to HSV?

Answer 20

-The virus infects sensory and autonomic neurons and establishes latent infection in the nerve ganglia. Primary infection is followed by reactivation throughout life (producing cold sore).

Question 21

• Caused by Coxsackie virus
• Relatively mild illness with fever and lymphadenopathy develops after an intubation period of about 10days. A painful papular or vesicular rash appears on palmopalantat surfaces of hands and feet. Diagnosis and management?

Answer 21

Hand, foot and mouth

-Antiviral treatment is not avaliable so managament consists of symptomatic relief: analgesics.