Dermatology Flashcards
(295 cards)
What is toxic epidermal necrolysis and Stevens-Johnson syndrome?
Blistering damage that occurs secondary to inflammation of the epidermis
Epidermal layer dies if severe, sheds, leaving exposed oozing dermis
What is the difference between toxic epidermal necrolysis and Stevens-Johnson syndrome?
Area of epidermal loss
TEN - >30%
SJS <10%
What are the features of Stevens Johnson syndrome?
Abrupt onset rash
Starting on trunk, extending rapidly
Mucocutaneous necrosis with at least 2 sites involved
Prodromal illness, flu like symptoms
What is erythema multiforme?
Target lesions
Initially seen on back of hands/feet before spreading to torso
Often of unknown cause Acute self-limiting Associated with HSV Infections or drugs Mucosal involvement absent or limited to one
What is the management of TEN/SJS and EM?
Early recognition, call for help Early referral, ITU or burns unit Supportive measures, maintain haemodynamics Fluid replacement, pain relief Stop drugs IV immunoglobulins, ciclosporins
What are some of the complications of TEN/SJS?
Sepsis
Electrolyte imbalance
Multi-system organ failure
What is erythroderma?
‘red skin’
Clinical state of inflammation of all the skin,
not a pathological diagnosis
What are the clinical features of erythroderma?
Skin is red, hot and scaly
May have generalised lymphadenopathy
Loss of control of temp
Bouts of shivering
Hypothermia from heat loss
High-output cardiac failure
Hypoalbuminaemia
Fluid loss
Capillary leak syndrome - cytokines released during inflammation cause vascular leakage - can lead to acute respiratory distress
What are the causes of erythroderma?
Dermatitis (eczema) including contact-allergic
Lymphoma
Drugs - sulphonamides, gold, sulphonylureas, penicillin, allopurinol
Psoriasis
Idiopathic
What is the management of erythroderma?
Treat underlying cause where known, stop drugs Methotrexate for psoriasis Keep patient warm Swab skin for infection Monitor vitals and serum albumin
Use emollients and wet wraps to maintain moisture
Mild topical steroids
What is the presentation of acute meningococcaemia?
Features of meningitis - headache, fever, neck stiffness
Septicaemia - hypotension, fever, neck stiffness
Non-blanching purpuric rash on trunk and extremities, may be preceded by blanching maculopapular rash
Can rapidly progress to ecchymoses, haemorrhagic bullae, tissue necrosis
What is the cause of acute meningococcaemia?
Gram negative diplococcus Neisseria meningitides
What is the sepsis 6?
Administer high flow oxygen Take blood cultures Give broad spec antibiotix e.g. benzylpenicillin Give IV fluid challaneges Measure serum Hb and lactate Measure accurate hourly urine output
What other management in meningococcaemia in important?
Prophylactic antibiotics e.g. rifampicin for close contacts, ideally within 14 days of exposure
What are the complications of acute meningococcaemia?
Septicaemic shock
Disseminated intravascular coagulation
Multi-organ failure
Death
What is necrotising fasciitis?
Rapidly spreading infection of the deep fascia secondary to tissue necrosis
Type 1 - aerobic and anaerobic bacteria seen post op (often in diabetes)
Type 2 - Group A streptococcus and can arise spontaneously in healthy individuals
What are risk factors for necrotising fasciitis?
Abdominal surgery, medical co-morbidities e.g. diabetes, malignancy
What is the presentation of necrotising fasciitis?
Often presents as rapidly worsening cellulitis with pain out of keeping with clinical features
Erythematous, blistering, necrotic skin
Systemically unwell, fever, tachycardia
Presence of crepitus - subcutaneous emphysema
X-Ray showing visible gas indicating gas-forming organism in soft tissue (absence does not exclude diagnosis)
What is the management of nec fasc?
Urgent referral, surgical debridement
IV antibiotics
Why are IV antibiotics alone ineffective in nec fasc?
The blood supply is compromised and vessels cannot deliver antibiotics to the necrotic tissues in sufficient concentration
What is eczema herpeticum?
Widespread eruption - monomorphic punched out erosions usually 1-3mm diameter
Serious complication of atopic eczema or other skin conditions e.g. pemphigus foliaceus
What is the presentation of eczema herpeticum?
Widespread eruption
Punched out erosions
History of preceding malaise and fever in patient known to have atopic dermatitis
Systemically unwell
What is the management of eczema herpeticum?
General supportive measures
IV antiviral therapy e.g. aciclovir
Antibiotics for bacterial secondary infection
Stop any non-essential therapies inc topical steroids
Ophthalmological review if any ocular involvement
What is angioedema?
Type 1 hypersensitivity reaction
Swelling of the dermis, subcut tissues and mucosae
Triggers can be allergic or non-allergic, but both cause release of inflammatory mediators