Skin infections Flashcards
What are erysipelas and cellulitis
Spreading bacterial infections of the skin
What part of the skin does cellulitis involve
Deep subcutaneous tissue
What parts of the skin does erysipelas involve?
Dermis and upper subcutaneous tissue
How is erysipelas distinguished from cellulitis?
Erysipelas has a raised well defined, red border
Which bacteria cause erysipelas and cellulitis?
Staphylococcus aureus and streptococcus pyogenes
How are erysipelas and cellulitis managed?
Antibiotics (flucloxacillin and benzylpenicillin)
Supportive care including bed rest, leg elevation, sterile dressings and analgesia
What are the complications of erysipelas and cellulitis
Local necrosis
Abscess
Septicaemia
What are the risk factors for erysipelas and cellulitis infection
Immunosuppression Ulcers Wounds Toeweb intertrigo Minor skin injury
How may someone with erysipelas or cellulitis present?
Most common in lower limbs
Local signs of inflammation - tumor (swelling), calor (warmth), dolor (pain), rubor (erythema)
Systemically unwell with fever, lymphangitis, malaise or rigors
Which age group commonly gets staphylococcal scaled skin syndrome
Infants and early childhood
What causes staphylococcal scaled skin syndrome
Production of a circulating epidermolytic toxin from phage group II, benzylpenicillin resistant (coagulase positive) staphylococci
How does staphylococcal scaled skin syndrome present?
Develops within a few hours to days and may be worse over the face, neck ,axilla and groin
A scaled skin appearance is followed by large flaccid bulla
Perioral crusting is common
There is intraepidermal blistering in this condition
Lesions are painful
Sometimes the eruption is more localised
Recovery within 5-7days
How can staphylococcal scaled skin syndrome be managed
Antibiotics- penicillinase resistant penicillin, fusidic acid, erythromycin or appropriate cephalosporin
Analgesia
List the 3 main groups of fungi causing skin infections
Dermatophytes
Moulds
Yeasts
Give examples of dermatophytes
Tinea/ringworm
Give examples of yeasts
Candidiasis
Malassezia
Give examples of moulds
Aspergillus
What does presentation of fungal skin infection vary with?
The site of infection
Describe the presentation of tinea corporis
Tinea infection of the trunk and limbs
Itchy, circular/annular lesions with clearly defined, raised and scaly edge
Describe the presentation of tinea cruris
Very itchy
Groin and natal cleft
Circular/annular lesions with clearly defined, raised and scaly edge
Describe tinea capitis
Ringworm infection of the scalp
Patches of broken hair, scaling and inflammation
Describe the presentation of tinea pedis (athletes foot)
Moist scaling and fissuring in toe webs, spreading to the sole and dorsal aspect of the foot
Describe the presentation of tinea manuum
Infection of the hand
Scaling and dryness of the palmar creases
Describe the presentation of tinea unguium
Infection of the nail
Yellow discolouration
Thickened, crumbly nail
What may happen when tinea is treated with corticosteroids
Tinea incognito - less scaly and ill defined lesions
Describe candidiasis presentation
White plaques on mucosal areas, erythema with satellite lesions on flexures
Describe the presentation of pityriasis/tinea versicolor
Scaly pale brown patches on upper trunk that fail to tan on sun exposure, usually asymptomatic
How do you manage fungal infections
Establish correct diagnosis - skin scrapings, hair or nail clippings (for dermatophytes), skin swabs (yeasts)
General measures - treat known preciptating factors, topical anti-fungal cream (terbinafine cream), oral antifungal agents (itraconzaole) for severe widespread infection.
Avoid the use of topical steroids - can lead to tinea incognito
Correct predisposing factors where possible
