skin infections Flashcards
what are the 3 main types of skin infection according to their sources?
1) bacterial eg staphylococcal + streptococcal
2) viral eg HPV, HSV, HZ
3) fungal eg tine, candida, yeasts
infestations like scabies and cutaneous leishmaniasis also occur
what is cellulitis?
involves the deep subcutaneous tissue
sprading bacterial infection of the skin
what is erysipelas?
an acute superficial form of cellulitis + involves the dermis + upper subcutaneous tissue
spreading bacterial infx of skin
what are the causes of erysipelas + cellulitis?
streptoccus progenies
staphylococcus aureus
what are the risk factors for cellulitis + erysipelas?
immunosuppression wounds leg ulcers toeweb intertrigo minor skin injury
how does cellulitis + erysipelas present?
most common in lower limbs
1) local signs of inflammation- swelling (tumour), erythema (rubber), warmth (calor), pain (dolor). can be associated with lymphangitis
2) systemically unwell with fever, malaise or riggers, esp with erysipelas
how is erysipelas distinguished from cellulitis?
by a well-defined red raised border
what is the management of cellulitis + erysipelas?
antibioitics eg flucloxacillin/benzylpenicillin
supportive care- rest, leg elevation, sterile dressings, analgesia
what are the complications of cellulitis + erysipelas?
local necrosis
abscess
septicaemia
what is staphylococcal scalded skin syndrome SSSS?
SSSS commonly seen in infancy + early childhood
a serious skin infection caused by the bacterium Staphylococcus aureus. This bacterium produces an exfoliative toxin that causes the outer layers of skin to blister and peel
what is the cause of staphyloccal scalded skin syndrome?
production of circulating epidermolytic toxin from phage group II, benzylpenicillin-resistant (coagulase positive) staphylococci
how does SSSS present?
develops within few hrs-days, can be worse over face, neck, axillae, groins.
recovery within 5-7days
1) scald-like then large flaccid bulla
2) perioral crusting typical
3) intraepidermal blistering
4) lesions v painful
5) eruption more localised
what is the management of SSSS?
1) antibiotics eg a systemic penicillinase-resistant penicillin, fusidic acid, erythromycin or cephalosporin
2) analgesia
what is a superficial fungal infection?
common and mild infx of superficial layers of skin, nails + hair
can be severe in immunocompromised
what are the 3 main groups of causes of superficial fungal infections?
1) dermatophytes- tinea/ringworm
2) yeasts- candidiasis, malassezia
3) moulds- aspergillus
how does superficial fungal infections present?
varies with site of infection
usually unilateral + itchy
what is tinea corporis?
tinea infection of trunk + limbs
itchy, circular/annular lesions with clearly defined, raised + scaly edge
what is tinea cruris?
tinea infection of groin + natal cleft
v itchy. like tinea corporis
what is tinea pedis
athlete’s foot
moist scaling + fissuring in towers, spreading to sole + dorsal aspect of foot
what is tinea manuum?
tinea infection of the hand
scaling + dryness in palmar creases
what is tinea capitis?
scalp ringworm
patches of broken hair, scaling + inflammation
what is tinea unguium?
tinea infection of the nail
yellow discolouration, thickened + crumbly nail
what is tinea incognito?
inappropriate treatment of tinea infection with topical or systemic corticosteroids
ill-defined + less scaly lesions
what is candidiasis?
candidal skin infection
white plaques on mucosal areas
erythema with satellite lesions in flexures
