Skin Infections Flashcards
Describe the epidemiology of skin disease
High rates in hot humid conditions and poor populations
Low rates in dry temperate conditions and rich populations
25% of GP skin consultations (UK)
What proportion of skin disease presentations are of infectious cause in the GP vs hospital
GP - 25%
Hospital - 5%
What are the manifestations of staphylococcus aureus skin infections
Impetigo - infection of sub corneal layer or epidermis
Folliculitis - infection of mouth of hair follicle
Ecthyma - Infection of full thickness of epidermis
Boli - abscess of the hair follicle
Carbuncle - abscess of several adjacent hair follicles
Describe treponema pallidum
Gram negative spirochaete Cause of Syphilis Sexually transmited disease 12 million new cases per year worldwide Increases transmission of HIV
What are the stages of syphillis infection
Primary (3-8 weeks)
secondary (6-12 weeks)
Latent - non clinical signs
Tertiary (years later)
Describe congenital syphillis
Acquired perinatally
Early and late manifestations
Miscarriage Still birth Prematurity Rashes Brain and neurological problems Bone disease
Describe primary, secondary and tertiary syphillis
primary - painless ulcer at inoculation site (genital or oral)
Secondary - Disseminated infection, Generalised rash and lymphadenopathy
Tertiary - Skin, neurological and vascular manifestations. Bone lesions and thoracic aneurysms
Give the following features of HHV-1: Synonym Target cell Disease Site of latency
HSV type 1
Muco-epithelial
Oro-genital herpes
Neurone
Give the following features of HHV-2: Synonym Target cell Disease Site of latency
HSV type 2
Muco-epithelial
Oro-genital herpes
Neurone
Give the following features of HHV-3: Synonym Target cell Disease Site of latency
VZV
Muco-epithelial
Chickenpox/shingles
Neurone
What are the clinical presentations of herpes simplex infection
Vesicular rash - 2 weeks
Eczema herpeticum
Herpes encephalitis
What are the medical considerations of staphylococcus aureus
Commensal Skin infections - most common cause MRSA Toxin production Bone, joint and lung infections Sepsis
What toxins can S. Aureus produce
Panton Valentine Leuocidin
Exfoliative toxin
TSST-1 (Toxic Shock Syndrome Toxin 1)
Enterotoxin
What is chickenpox caused by
Varicella Zoster
What are the symptoms of varicella zoster infection
Vesicular rash, in groups, concentrated on the face Lesions in the mouth Malaise Fever Sore throat
What are the two types of fungal infections of the superficial skin
Dermatophytes
Yeasts
Give an example of a dermatophyte, state where they grow and describe its structure
E.g. Trichophyton rubrum
Grow in keratin
Long hyphae, grow from tip
Give an example of a yeast, state where they grow and describe its structure
E.g. Candida
Grow on warm wet surfaces
single cell and bud
What are some types of dermatophytes
Tinea unguium (toenails) Tinea capitis Tinea Manuum (form animals) Tinea pedis (sold of foot) Tinea cruris - gential area
Give an example of a yeast infection of the skin
Candida Intertrigo
Red rash that is often found in places where sweat is produced.
What is sarcoptes scabei
Female mite burrows in the surface of the epidermis (stratum corneum) to cause scabies
What is the key sign of scabies
the burrow (4mm squiggle/s-shapes with a black dot (the mite) at one end)
Where are burrows from scabies usually found
Breast area, axillary Umbilical Elbows Wrists Genital Anal area
