Skin Infections and Infestations Flashcards
what are characteristics of impetigo?
common, highly contagious
most common bacterial infection
what are predosposing factors for impetigo?
warm temperature, high humidity
- Poor hygiene
- Skin trauma
what is the organism responsible for impetigo?
staph aureus
what is the treatment for impetigo?
Local wound care
Topical antibiotics
what is folliculitis?
Infection of the hair follicule
what is the infectious cause of folliculitis?
Staph.aureus
what are the predisposing factors of folliculitis?
occlusion, maceration and hyperhydration, shaving or waxing, topical corticosteroids and diabetes.
where are you likely to get folliculitis?
Face, chest, back, axillae or buttocks
how may you identify the causative organism?
bacterial cultures
what is the treatment of folliculitis?
antibacterial washes
antibacterial ointments
what is erysipelas?
Infection of the dermis with lymphatic involvement
whats the most common causative organism for erysipelas?
group A streptococci.
whos most likely to get erysipelas?
Disease of the very young, the aged, the debilitated and those with lymphedema or chronic cutaneous ulcers.
what sre the symptoms of erysipelas?
The affected skin feels hot, tense and indurated.
Face, lower extremities
fever, chills, malaise and nausea
how would you diagnose erysipelas?
clinical, Lab may show an elevated leukocyte count with a left shift.
what is the treatment of erysipelas?
10-14 day course of penicillin
what is cellulitis?
Infection of the deep dermis and subcutaneous tissue caused most commonly by Str.pyogenes and S.aureus
what are signs and symptoms of cellulitis?
Affected area shows rubor (erythema), calor (warmth), dolor (pain) and tumor (swelling)
Lesion has ill-defined, non-papable borders.
Children: head and neck, adults: extremities
how would you diagnose cellulitis?
clinical. Leukocyte count is usually normal and blood cultures are negative in most cases
what is the treatment of cellulitis?
Antibiotics (depending on systemic symptoms and gravity, also risks factors
what is syphilis and how is it caused?
Complex sexually transmittedinfection(STI) caused by thebacteriaTreponema pallidum.
what are the symptoms of syphilis?
Widespreadrashand ‘flu-like symptoms
what are the symptoms of primary syphilis?
Initially syphilis appears as a painless sore (ulcer) where theinfectionentered (usually around the genitals, anus or mouth) and may go unnoticed. The sore is known as a chancre.
Single small firm red painlesspapulequickly ulcerates
when is secondary syphilis?
3 weeks to 3 months after the 1st stage, awidespreadskinrashoccurs.
what is the symptoms of secondary syphilis?
Rash may be subtle or appear as rough, red or reddish brownpapulesor patches.
Occurs typically on the trunk and frequently affects palms and soles. May be mistaken for other conditions. Therashdoes not itch.
what are characteristics of tertiary syphilis?
Patient is infectious and can pass theinfectionon to partner.
Usually normal,i.e. no signs on clinical examination.
name some viral infections
Herpes simplex Chicken pox Shingles Viral warts Molluscum contagiosum
what is herpes simples virus?
Orolabial and genital infection
HSV-1: Present in aprox. 90% of individuals between 20-40 years old. Often asymptomatic in children <10 years old
HVS-2: Genital infection ( association with sexual activity)
what is the aetiology of chickenpox and shingles?
VZV
what does chickenpox cause in children?
anacutefeverand blisteredrash, mainly in children
how is chickenpox spread?
easily spread from person to person by breathing in airborne respiratory droplets from an infected person’s coughing or sneezing or through direct contact with the fluid from the open sores.
what is the treatment of chickenpox
sypmtomatics, calamine lotion
what is shingles?
Localised, blistering and painfulrashcaused by reactivation of varicella-zoster virus (VZV).
It is characterised bydermatomaldistribution.
the blisters are confined to theVZV remains dormant indorsalrootganglianerve cells in the spine
what are the complications of shingles?
infection, Post-herpeticneuralgia
whats the treatment of shingles?
keep the area clean to prevent infection, pain relief and rest
what is viral warts?
Human papillomavirus
whats the treatment for viral warts?
Salicylic Acid, Cryotherapy
what is molluscum contagiosum?
common viral skininfection
Mainly affects infants and young children under the age of 10 years.
It is more prevalent in warm climates than cool ones, and in overcrowded environments
what causes molliscum contagiosum?
poxvirus ( Poxviridae family
what is the treatment of molluscum contagiosum?
Curettage, liquid nitrogen, chemovesicants
name some fungal infections
Dermatophytosis
Candidiasis
Pityriasis versicolor
what is dermatophytoses?
Usually postpuberal hosts
Except: tinea captis, most common in children
what are predisposing factors for mucocutaneous candida infections?
DM occlusion hyperidrosis broad spectrum antibiotics immunosuppression
what are the symptoms of Mucocutaneous Candida infections?
Candida albicans
On the skin, erythematous patches that are often accompanied by satellites pustules.
Intertriginous zones ( submammary, inguinal creases, finger spaces…) and diaper areas in infants.
what is the treatment of Mucocutaneous Candida infections
: remove predisposing factors, topical antifungals, oral antifungal in some cases
what is the organism responsible for Pityriasis Versicolor
Malassezia sp
what are the symptons of Pityriasis Versicolor
High temperatures and humidity, oily skin, excessive sweating
what are the signs of Pityriasis Versicolor
Multiple oval to round patches with mild scale
what is the treatment of Pityriasis Versicolor
topical antimycotic ( shampoos, creams)
what is the causative organism for scabies?
Host-specific itch mite Sarcoptes scabiei
what is the transmission of scabies?
via direct close contact
Worldwide
what are predisposing factors of scabies?
overcrowding, delayed treatment
how would you diagnose scabies?
skin scraping, burrows visualization
when is the itch of scabies more severe?
at night, disturbing sleep
where does scabies affect?
trunk and limbs
what is the treatment of scabies?
: Antiscabietic topical treatment in the patient and close contacts, repeat after 1 week. Oral medicine might be needed in some cases
where do the lice prefer?
favour the nape of the neck and the skin behind the ears
what are red-brown spots due to on lice?
due to excreted digested blood.
what is the treatment of head lice?
: at least 2 applications of an insecticide and/or physical methods.
