Infections and infestations of the skin Flashcards
what organism causes impetigo?
staph aureus
staph pyrogens to a lesser degree
what does impetigo look like?
yellow crusted erosions
rapid extension to surrounding skin
what are the pre disposing factors of impetigo?
warm temperatures, humidity
poor hygiene
skin trauma
what is the treatment for impetigo?
wound care
topical antibiotics
what organism causes folliculitis?
staph aureus
what is folliculitis?
infection of the hair follicles
where does folliculitis commonly affect?
face chest back axillae buttocks
what are the pre disposing factors for folliculitis?
occlusion shaving or waxing maceration with hyper hydration topical corticosteroids diabetes
what is the treatment for folliculitis?
antibiotic ointments
antibacterial washes
how would you investigate the causative organism if you suspected folliculitis?
bacterial culture
what is erysipelas?
infection of the superficial dermis with lymphatic involvement
what is the presentation of erysipelas?
hot, tense erythema with well defined edges
patient may experience pyrexia, malaise, rigors, nausea
occurs in the face and lower extremities
what may lab results show with erysipelas?
elevated leukocyte count with a left shift
what is the treatment for erysipelas?
10-12 day course of penicillin
what organism is responsible for cellulitis?
staph aureus and strep pyrogens
what is cellulitis?
infection of the deep dermis and subcutaneous tissue
what are the predisposing factors for cellulitis?
lymphoedema diabetes alcoholism IV drug abuse peripheral vascular disease
what is the presentation of cellulitis?
shows 4 cardinal signs of inflammation:
- erythema (rubor)
- swelling (tumor)
- heat (calor)
- pain (dolor)
what is the most common distribution of cellulitis in adults and children?
children = head and neck adults = extremities
what is the treatment for cellulitis?
anti biotics
what organisms causes syphilis?
treponema pallidum
what is the presentation of primary, secondary and tertiary syphilis?
primary = painless sore/ulcer known as a chancre secondary = wide spread rash + flu like symptoms tertiary = solitary granulomatous lesions (gummas) found on skin, mouth, throat or in bone
where would you find a chancre of primary syphilis?
genitals
anus
mouth
where does a secondary syphilis rash typically occur?
trunk
palms
soles of the feet
how would you test for syphilis?
non-specific non-treponema test (VDRL)
specific anti-treponema antibody test (TTPA)
what is the treatment for syphilis?
penicillin (injection)
what is the treatment for herpes simplex?
anti-viral (topical or systemic depending)
what organism that causes chicken pox?
varicella-zoster
what organism is responsible for shingles?
herpes zoster
what are complications from shingles?
infection
post herpetic neuralgia
(pain in the area after the virus goes away)
what virus is responsible for warts?
human papilloma virus
what are the treatments for warts?
cryotherapy (liquid nitrogen)
salicylic acid
what organism is responsible for molluscum contagiousm?
poxvirus
what is the presentation of molluscum contagiosum?
lesions are firm, umbillicated, pearly papule with waxy surface
most common in skin folds and genital region
what is the treatment for molluscum contagiosum?
curettage
liquid nitrogen
chemovesicants
what is the organism that causes ring worm?
fungal - tinea corporis
what is the type of fungus that causes ring worm?
dermatophyte - tinea corporis
what infections are candida albicans responsible for?
mucocutaneous candida infections
what is the presentation of mucocutaneous candida infections?
erythema patches
often accompanied by satellite pustules
settling lesions around patch
what are the pre disposing factors for mucocutaneous candida infections?
diabetes occlusion i.e. napppy rash hyperhidrosis brand spectrum antibiotics immunosuppression
what is the treatment for mucocutaneous candida infections?
remove predisposing factor
topical/oral anti-fungals
what organism is responsible for pityriasis versicolor?
malassezia sp.
what is the presentation of pityriasis versicolor?
multiple oval round patches with mild scale
occurs in sebum riches areas of the skin
what are the predisposing factors for pityriasis versicolor?
high temperatures
humidity
oily skin
excessive sweating
what is the treatment for pityriasis versicolor?
topical antimycotic
what organism causes scabies?
sarcoptes scabie
what a re the pre disposing factors for scabies?
over crowding
direct close contact with an infected person
delayed treatment
what is the presentation of scabies?
burrows that appear as grey irregular tracts between webs of fingers, palms and wrists
also affects trunk and limbs - sparing the scalp
what is the treatment for scabies?
anti-scabietic topical treatment (oral if severe)
