Infections Flashcards
(6 cards)
What is erysipelas
Acute superficial form of cellulitis, involves dermis and upper subcutaneous tissues
Distinguished from cellulitis by well-defined red raised border
What is cellulitis?
Cause, presentation, treatment, complications
Spreading bacterial infection of skin, involves deep subcutaneous tissue
Causes: strep pyogenes and staph aureus
Risk factors: immunosuppression, wounds, leg ulcers, toeweb intertrigo, minor skin injury
Most common lower limbs, local signs of inflammation, may be associated with lymphangitis. Systemically unwell with fever, malaise or rigors, particularly with erysipelas.
Tx: flucloxacillin or benzylpenicillin, supportive care - leg elevation sterile dressing and analgesia
Complications: local necrosis, abscess and septicaemia
What is staphylococcal scalded skin syndrome?
Include Tx
Commonly seen in infancy and early childhood - production of circulating epidermolytic toxin from phage group II, benzylpenicillin-resistant (coagulase positive) staphylococci
Develops within few hours - few days, may be worse over face, neck, axillae or groins. Scald-like skin appearance is followed by large flaccid bulla.
Perioral crusting is typical, intraepidermal blistering, lesions are very painful, sometimes the eruption is more localised, recovery within 5- 7days
Treatment: Abx e.g. systemic penicillinase-resistant penicillin, fusidic acid, erythromycin or appropriate cephalosporin. analgesia
What are the main superficial fungal infections?
Common and mild infection of superficial layers of skin, nails and hair - can be severe in immunocompromised individuals
Dermatophytes (tinea / ringworm)
Yeasts (candidiasis / malassezia)
Moulds (e.g. aspergillus)
Types of tinea?
Tinea corporis: usually trunk and limbs: itchy, circular or annular lesions with clearly defined, raised and scaly edge
Tinea cruris: groin and nasal cleft, similar, very itchy
Tinea pedis: athlete’s foot, moist scaling and fissuring in toewebs, spreading to sole and dorsal aspect of foot
Tinea manuum: hands - scaling and dryness in palmar creases
Tinea capitis: scalp ringworm - patches of broken hair, scaling and inflammation
Tinea unguium: nail infection - yellow discolouration, thickened and crumbly
Tinea incognito: ill-defined, less scaly lesions - inappropriate Tx of tinea infection with topical or systemic corticosteroids
Tinea versicolor (pityriasis): Malassezia fufur (yeast) infection, scaly pale brown patches on upper trunk, fail to tan, usually asymptomatic
Also - candidiasis - white plaques on mucosal areas, erythema with satellite lesions in flexures
Management of fungal infections
Correct Dx: skin scapings, hair/nail clippings (dermatophytes) or skin swabs (yeasts)
Treat underlying immunosuppressive condition, moist environment
Topical antifungals e.g. terbinafine cream
Oral antifungal e.g. itraconazole for severe / widespread or nail infection
Avoid topical steroids, can lead to tinea incognito
