Skin Infections and Infestations Flashcards
What are the types of skin infections?
Bacterial
Viral
Fungal
What is the difference between cellulitis and erysipelas?
Cellulitis involves deep subcutaneous tissue
Erysipelas is acute cellulitis involving the dermis and upper subcutaneous tissue
What causes Erysipelas and Cellulitis?
Strep pyogenes
Staph aureus
What are some risk factors for getting cellulitis/erysipelas?
Immunosuppression Wounds Leg ulcers Toeweb intertrigo Minor skin injury
How do cellulitis and erysipelas normally present?
Lower limb
Inflammation - swelling, red, pain, warm
Systemically unwell - fever malaise or rigors
How does erysipelas present differently to cellulitis?
Well defined red raised border
How do you manage erysipelas/cellulitis?
Antibiotics - fluclox/benpen
Supportive care - rest, leg elevation, sterile dressing, analgesia
What are the complications of cellulitis and erysipelas?
Local necrosis
Abscess
Septicaemia
What is staphylococcal scalded skin syndrome (SSSS)?
Serious skin infection seen in infancy and early childhood caused by S Aureus
What causes SSSS?
Benpen resistant Staph Aureus produce circulating epidermolytic toxin that causes outer layers of skin to blister and peel
How does SSSS present?
Scald like appearance followed by large flaccid bulla
Perioral crusting
Intraepidermal blistering
Painful lesions
What are the timescales for SSSS?
Develop within few hours to few days
Recover within 5-7 days
How is SSSS managed?
Antibiotics - fusidic acid, erythromycin or other appropriate (CHECK LOCAL GUIDELINES)
Analgesia
When can superficial fungal infections be severe?
Immunocompromised individuals
Where do fungal infections affect?
Skin
Nails
Hair
What are the main groups of organisms that cause fungal infections?
Dermatophytes - tinea/ringworm
Yeasts - candidiasis, malassezia
Moulds - aspergillus
How does tinea corporis present and how does it present?
Itchy circular lesions with clear defined raised scaly edge on the trunk and limbs
How does tinea cruris present and how does it present?
Very itchy, circular lesions with clear defined raised scaly edges on the groin and nasal cleft
What is tinea pedis and how does it present?
Athletes foot - moist scaling and fissuring in toewebs spreading to the sole and dorsum of the foot
What is tinea manuum and how does it present?
Tinea infection of the hand - scaling and dryness in the palmar creases
What is tinea capitis and how does it present?
Scalp ringworm - patches of broken hair with scaling and inflammation
What is tinea unguium and how does it present?
Tinea infection of the nail - yellow discolouration with a thickened crumbly nail
What is tinea incognito and how does it present?
Inappropriate treatment of tinea infection with steroids
Ill defined and less scaly lesions
How do candidal infections present?
White plaques on mucosal areas
Erythema with satellite lesions in flexures
What is pityriasis and how does it present?
Malassezia furfur infection
Scaly pale brown patches on upper trunk that fail to tan
How are fungal infections investigated?
Skin scrapings
Hair or nail clippings
Skin swabs
How are fungal infections managed?
Treat precipitating factors - immunosuppresion, moist environment
Topical antifungals - terbinafine
Oral antifungals - itraconazole if severe
Avoid use of topical steroids
