Acute and Emergency Dermatology Flashcards
describe the properties of skin as an organ?
- The skin is the largest organ in the body
- 10% of body mass of average person
- Like any organ the skin can fail
A
sepsis
B
Hypo- and Hyper- thermia
C
Protein and fluid loss
Renal impairment
Peripheral vasodilation
what is Erythroderma?
Erythroderma is the term used to describe intense and usually widespread reddening of the skin due to inflammatory skin disease
A descriptive term rather than a diagnosis
“Any inflammatory skin disease affecting >90% of total skin surface”
what are the causes of erythroderma?
Psoriasis
Eczema
Drugs
Cutaneous Lymphoma
Hereditary disorders
Unknown
what are the principles of management for erythroderma?
Appropriate setting - ?ITU or burns unit
Remove any offending drugs
Careful fluid balance
Good nutrition
Temperature regulation
Emollients – 50:50 Liquid Paraffin : White Soft Paraffin
Oral and eye care
Anticipate and treat infection
Manage itch
Disease specific therapy; treat underlying cause
are drug reactions common or rare?
Common - 5% of inpatients
when do drug reacitons occur?
Can occur to any drug
Commonly 1-2 weeks after drug - Within 72 hours if re-challenged
what are examples of a mild and severe drug reactions?
- Mild - Morbilliform exanthem
- Severe - Erythroderma, Stevens Johnson Syndrome/Toxic epidermal necrolysis, DRESS
What is Stevens Johnson Syndrome/Toxic Epidermal Necrolysis?
- 2 conditions which are thought to form part of the same spectrum
- Rare:
- 1-2/million/year (SJS)
- 0.4-1.2/million/year (TEN)
(pictures showing Stevens Johnson Syndrome (SJS) & Toxic Epidermal necrolysis (TEN))
Stevens Johnson Syndrome/Toxic Epidermal Necrolysis can occur secondary to what drugs?
Antibiotics
Anticonvulsants
Allopurinol
NSAIDs
Can be delayed onset
In Stevens Johnson Syndrome/Toxic Epidermal Necrolysis what percentage of skin is usually affected?
what are the clinical features of SJS?
- Fever, malaise, arthralgia (pain in a joint)
- Rash:
- Maculopapular, target lesions, 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?
- Often presents with prodromal febrile illness
- Ulceration of mucous membranes
- Rash:
- May start as macular, purpuric or blistering
- Rapidly becomes confluent
- Sloughing off of large areas of epidermis - ‘desquamation’ (skin peeling) > 30% BSA
- Nikolsky’s sign may be positive
what is the management of SJS and Toxic Epidermal Necrolysis?
- Identify and stop culprit drug as soon as possible
- Supportive therapy
Not common so no high quality trials to see what works:
- ?High dose steroids
- ?IV immunoglobulins
- ?Anti-TNF therapy
- ?Ciclosporin
what is the prognosis of SJS and TEN and how is it determined?
Mortality up to 10% (SJS)/30% (TEN)
SCORTEN:
- Age >40
- Malignancy
- Heart rate >120
- Initial epidermal detachment >10%
- Serum urea >10
- Serum glucose >14
- Serum bicarbonate <20
what are the long term complications of SJS and TEN?
Pigmentary skin changes
Scarring
Eye disease and blindness
Nail and hair loss
Joint contactures
what is Erythema Multiforme?
Hypersensitivity reaction usually triggered by infection - Most commonly HSV, then Mycoplasma pneumonia
SJS and TEN are drug related but this is viral related
how does Erythema Multiforme present?
• Abrupt onset of up to 100s of lesions over 24 hours:
- Distal to proximal
- Palms and soles
- Mucosal surfaces (EM major)
- Evolve over 72 hours
- Pink macules, become elevated and may blister in centre
- “Target” lesions
SJS lesions are atypical target lesion but in this there is typical target lesions
How do you treat Erythema Multiforme?
- Self limiting and resolves over 2 weeks
- Symptomatic and treat underlying cause
How common is Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), what is its prognosis and how long is its onset?
- Incidence estimated between 1 in 1000-10,000
- Mortality up to 10%
- Onset 2-8 weeks after drug exposure
DRESS can be up to 2 months later from drug where as TEN tends to be quite soon after
DRESS and TNE are the 2 most severe type of drug reactions you do not want to miss
what are the clinical features of DRESS?
- Fever and widespread rash
- Eosinophilia and deranged liver function
- Lymphadenopathy
- +/- other organ involvement
what is the treatment of DRESS?
- Stop causative drug
- Symptomatic and supportive
- Systemic steroids
- +/- Immunosuppression or immunoglobulins
photos showing blistering:
Blistering conditions can be due to many things but we are going to think about autoimmune conditions
What is pemphigus?
Pemphigus is a rare skin disorder characterized by blistering of your skin and mucous membranes
what are the clinical features of pemphigus?
Antibodies targeted at desmosomes
Skin - flaccid blisters, rupture very easily
Intact blisters may not be seen
Common sites - face, axillae, groins
Nikolsky’s sign may be +ve
Commonly affects mucous membranes
Ill defined erosions in mouth
Can also affect eyes, nose and genital areas
how is the pathology of pemphigus seen?
- Immunofluorescence
- Histopathology
Pictures:
Split in epidermis seen on the right photo
Left is key test for diagnosing blistering disorder
Left is strongly positive for IgG
how adn where are blisters formed in pemphigoid?
- Antibodies directed at dermo-epidermal junction
- Intact epidermis forms roof of blister
- Blisters are usually tense and intact
This one is deeper
Where as last one was in-between the individual keratinocyte
This is type of blister seen on foot due to shoe
what is the difference between Pemphigus vs Pemphigoid?
Both are autoimmune attacks
Pemphigoid tend to be well
Both immunosuppressants as treatment
pemphigus - cell to cell adhesion is impaired, affects individual keratinocytes
pemphigoid - deeper, affects between the dermis and epidermis
what are the causes of Erythrodermic psoriais and Pustular Psoriasis?
- Can occur without previous history of psoriasis
- Common causes:
- Infection
- Sudden withdrawal of oral steroids or potent topical steroid
what are the clinical features of Erythrodermic psoriais and Pustular Psoriasis?
- Rapid development of generalised erythema, +/- clusters of pustules
- Fever, elevated WCC
what is the treatment of Erythrodermic psoriais and Pustular Psoriasis?
- Exclude underlying infection (swab), bland emollient, avoid steroids
- Often require initiation of systemic therapy
what is Eczema Herpeticum? and its symptoms?
- Disseminated herpes virus infection on a background of poorly controlled eczema
- Monomorphic blisters and “punched out” erosions - Generally painful, not itchy
- Fever and lethargy
Lots of tiny vesicles – fluid collections
Very painful
what is the treatment and management of Eczema Herpeticum?
- Treatment dose Aciclovir
- Mild topical steroid if required to treat eczema
- Treat secondary infection
- Ophthalmology input if peri-ocular disease - emergency
- In adults consider underlying immunocompromise
who is Staphylococcal Scalded Skin Syndrome common in? and what is the initial infection?
- Common in children, can occur in immunocommpromised adults
- Initial Staph. infection - May be subclinical
Infective complication
Confused with TEN
But here it is in children
what are the clinical features of Staphylococcal Scalded Skin Syndrome?
- Diffuse erythematous rash with skin tenderness
- More prominent in flexures
- Blistering and desquamation (skin peeling) follows - Staphylococcus produces toxin which targets Desmoglein 1
- Fever and irritability
What is the treatment of Staphylococcal Scalded Skin Syndrome?
- Require admission for IV antibiotics initially and supportive care
- Generally resolves over 5-7 days with treatment
what is Urticaria?
Urticaria, also known as hives, is an outbreak of swollen, pale red bumps or plaques (wheals) on the skin that appear suddenly – either as a result of the body’s reaction to certain allergens, or for unknown reasons. Hives usually cause itching, but may also burn or sting
what are other names for Urticaria?
Weal, wheal or Hive
What does Urticaria cause?
Central swelling of variable size, surrounded by erythema. Dermal oedema
itching, sometimes burning - Histamine release into dermis
fleeting nature, duration: 1- 24 hours
what is Angioedema?
Deeper swelling of the skin or mucous membranes
What are the causes of Acute Urticaria (< 6 week History)?
- Idiopathic - 50%
- Infection, usually viral - 40%
- Drugs, IgE mediated - 9%
- Food, IgE mediated - 1%
What is the treatment of Acute Urticaria (< 6 week History)?
- Oral antihistamine - Taken continuously, Up to 4 x dose
- Short course of oral steroid may be of benefit if clear cause and this is removed
- Avoid opiates and NSAIDs if possible (exacerbate urticaria)
What are the causes of Chronic Urticaria (> 6 week history)?
- Autoimmune/Idiopathic - 60%
- Physical - 35%
- Vasculitic - 5%
- Rarely a Type 1 hypersensitivity reaction
What is the management of Chronic Urticaria?
Limited role for oral steroids. No good evidence base
Omalizumab:
- Monoclonal antibody to IgE, mechanism of action unknown
- Recently licensed for use in chronic spontaneous urticaria
- 300mg S/C ever 4 weeks
- £6000 per year per patient
