Flashcards in Acute & Emergency Dermatology Deck (39)
Name consequences cause by the failure of skin functions
• Mechanical barrier to infection -> sepsis
• Temperature regulation -> hypo and hyperthermia
• Fluid and electrolyte balance ->
1. Protein and fluid loss
2. Renal impairment and vasodilation
What is erythroderma?
A descriptive term rather than a diagnosis
Any inflammatory skin disease affecting >90% of total skin surface
Usually effects older people
What are different causes of erythroderma?
• Cutaneous Lymphoma
• Hereditary disorders (presents as neonates with genetic defect in skin formation)
What is a drug that causes erythroderma "red man syndrome"?
What are the principles of management for erythronderms?
• Remove any offending drugs
• Careful fluid balance (don't want to push into cardiac failure)
• Good nutrition (loss of protein)
• Temperature regulation (minimise fluid loss)
• Emollients - 50:50 liquid paraffin:White soft paraffin (acts as an artificial barrier)
• Anticipate and treat infection
• Oral and eye care
• Disease specific therapy; treat underlying cause
Describe drug reactions
• Can occurs to any drug
• Commonly 1-2 weeks after drug
• Mild: morbilliform exanthem
• Severe: erythroderma, Stevens Johnson Syndrome/Toxic epidermal necrolysis, DRESS
What occurs in Stevens Johnson Syndrome (SJS) and Toxic Epidermal necrolysis (TEN)?
Loss of epidermis on top of dermis (erosions)
What differentiates Stevens Johnson Syndrome (SJS) and Toxic Epidermal necrolysis (TEN)?
Severity of the two conditions
• If surface of epidermal detachment < 30% --> SJS
• Overlap 20-30%
• TEN -> 30%
What drugs can cause Stevens Johnson Syndrome (SJS) and Toxic Epidermal necrolysis (TEN)?
• Allopurinol (used for gout)
What are the clinical features of SJS?
• Fever, malaise, arthralgia
- Maculopapular, target lesions (dusky centre with red outline), blisters
- Erosions covering <10% of skin surface
• Mouth ulceration
- Greyish white membrane
- Haemorrhagic crusting
• Ulceration of other mucous membranes
What are the clinical features of Toxic Epidermal Necrolysis (TEN)?
• Profromal febrile illness
• Ulceration of mucous membranes
- Macular, purpuric (small vessel bleed) or blistering
- Sloughing off of large areas of epidermis > 30%
- Nikolsky's sign - removal of epidermis when rubbed
How is the severity of SJS/TEN determined?
One point given for each positive:
• Age >40
• Heart rate >120
• Initial epidermal detachment >10%
• Serum urea >10
• Serum glucose >14
• Serum bicarbonate <20
Using the SCORTEN score, how is prognosis determined?
0-1 - > 3.2%
2 - 12.1%
3 - 35.3%
4 - 58.3%
> 5 - > 90%
What are the long term complications of SJS/TEN?
• Pigmentary skin changes (as melanocytes found in epidermis)
• Eye disease and blindness
• Nail and hair loss
• Joint contactures
What is the management for SJS/TEN?
• Identify and stop causative drugs asap
• Supportive therapy
What is erythema multiforme?
Hypersensitivty reaction usually triggered by infection
Usually by a virus (herpes) and this is how it is differentiated from TEN
What occurs in erythema multiforme?
Abrupt onset of up to 100s of lesions over 24 hours
• Distal -> proximal
• Palms and soles
• Mucosal surfaces (EM major)
• Evolve over 72 hours - pink macule, become elevated and may blister
What is the treatment of erythema multiforme?
• Self living and resolves over 2 weeks
• Symptomatic and treat underlying cause
What occurs in DRESS?
• Onset 2-8 weeks after drug exposure
• Fever and widespread rash
• Eosinophilia and deranged liver function
+/- other organ involvement
What is the treatment of DRESS?
• Stop causative drug
• Symptomatic and supportive
• Systemic steroid
• +/- immunosuppression or immunoglobulins
What is pemphigus?
• Antibodies targeted at desmosomes (between keratinocytes, causing separation)
• Skin – flaccid blisters, rupture very easily
• Intact blisters may not be seen
• Common sites – face, axillae, groins
• Nikolsky’s sign may be +ve
What are the clinical features of pemphigus?
• Commonly affects mucous membranes
• Ill defined erosions in mouth
• Can also affect eyes, nose and genital areas
Describe the pathology of pemphigus
• Immunoflourescence - stain with antibodies, which shows attachment of antigen to keratinocytes
• Histopathology - shows detachment between keratinocytes
What is pemphigoid?
• Antibodies directed at dermo-epidermal junction
• Intact epidermis forms roof of blister
• Blisters are usually tense and intact
What are the differences between pemphigus and pemphigoid?
• Middle age
• Blisters fragile - may not be seen intact
• Treat with systemic steroid, dress erosions and support
• Blisters often intact and tense
• Topical steroid if localised; systemic required if diffuse
What are the features of erythrodermic psoriasis and pustular psoriasis?
• Can occur without history of psoriasis
• Common causes: infection, sudden withdrawal of steroids
• Rapid development of generalised erythema +/- clusters of pustules
• Fever, elevated WCC
What is used to treat erythrodermic psoriasis and pustular psoriasis?
What are the clinical features of eczema herpeticum?
Monomorphic blisters (all look similar) and “punched out” erosions
Generally painful, not itchy
Fever and lethargy