December 4, 2015 - Infection

Question 1

Signs of Inflammation

Answer 1

Redness

Heat

Pain

Swelling

Question 2

Common Organisms for Bacterial Skin Infection

Answer 2

• Staphylococcus aureus*
• Streptococcus pyogenes*

Group A Streptococcus

Question 3

Impetigo

Answer 3

Caused by S. aureus

Rapidly evolving generalized exfoliative disease of young infants. Has “honey-coloured crusts”.

Question 4

Staph Scalded Skin

Answer 4

Caused by S. aureus

Epidermolytic toxin seperates skin below the stratum corneum. This is not full thickness skin peeling. Systemic reaction to exotoxin.

Question 5

Folliculitis

Answer 5

Inflammation of the follicles.

Acne vulgaris is technically a folliculitis.

Question 6

Furuncle

Answer 6

A deeper folliculitis.

Often called a boil.

Tender is hot, with a single draining opening. Typically a few deep hair follicles that are involved with S. aureus.

Question 7

Carbuncle

Answer 7

Multiple deep communicating furuncles.

These have multiple draining openings.

Question 8

Ecthyma

Answer 8

Often caused by Streptococcus pyogenes

Punched out deep ulcers.

Often heal with scarring.

Question 9

Cellulitis

Answer 9

Deeper seated infection of S. aureus

Local erythema and swelling that spreads rapidly

Skin often shows superficial necrosis after several days without treatment

Strep cellulitis can occur too and spreads much more rapidly (48 hours).

Question 10

Lymphangitis

Answer 10

Inflammation tracking up lymphatic vessels

Question 11

Erysipelas

Answer 11

Actute beta hemolytic group A strep

Involving superficial dermal lymphatics

Dharpyl marginated painful plaque

May have systemic symptoms

Question 12

Necrotizing Fasciitis

Answer 12

“Flesh eating disease”

Intense pain is often the first symptom, then cutaneous changes come late. This spreads across fascial planes and causes necrosis of subcutaneous tissue and fascia. Patients can get ill very, very quickly.

Often caused by strep and often needs surgical debridement.

Question 13

Chicken Pox

Answer 13

“Dew drop on a petal”

Caused by Varicella zoster

Lesions appear in three successive “crops”

Heals in 10-14 days

Question 14

Shingles

Answer 14

Reactivation of Varicella zoster

Dermatomal in distribution

Major complication is post-herpetic neuralgia

Give antivirals, ideally in first 72 hours.

Question 15

Warts

Answer 15

Caused by HPV

70% gone in a year, 90% gone in two. Remove only if unsightly or causing pain.

If lots of warts, consider immunodeficiency.

Question 16

Molluscum Contagiosum

Answer 16

Pox (DNA) Virus

Umbilicated papules

Considered an STD

* May appear with eczema. Do not put steroids on. If requiring treatment, may be cryo’d, keratolytized, laser’d etc.

Question 17

Dermatophyte Infections

Answer 17

What you see is the host reaction to the fungus.

Consider fungal scraping for all atypical scaling inflammatory dermatoses.

Question 18

Tinea Pedis

Answer 18

Fungal infection of the feet. (dermatophyte)

Question 19

Tinea Unguis

Answer 19

Fungal infection of the nail. (dermatophyte)

Very difficult to treat. Requires systemic anti-fungals for ~3 months

Question 20

Candidiasis

Answer 20

Candida albicans

NOT normal for thrush to be seen after 1 year of age. Think immunodeficiency.

Question 21

Tinea Versicolour

Answer 21

Malassezia globosa

Species of yeast that is a normal colonizer of adult skin. Causes discolouration of the skin in the affected areas.

Question 22

Scabies

Answer 22

A parisitic infection that is intensely pruritic. Burrows are found on the hands in adults, and in the scamp and feet for children.

A massive pain in the ass.

Question 23

Lice

Answer 23

Have to remove each of the knits.