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EMERGENCY MEDICINE
Liverpool Hospital
The Weekly Probe
19th June, 2012
Volume 15, Issue 18
THIS WEEK
1. Last week’s case – Erythema Multiforme
2. Dermatology nomenclature
3. Next week’s case
4. Joke of the Week
LAST WEEKS CASE – ERYTHEMA MULTIFORME
A 65 year-old man presents to the emergency department with fevers, red eyes and a mildly pruritic,
non-tender rash. He has had no historical evidence of mycoplasma or herpes infection and was noted
to be on a number of medications including voltaren, ezetriol, pariet and frusemide, (all of which have
been reported to produce erythema multiforme).
On examination, he has a variety of multiform rashes including patches, discrete annular plaques,
and confluent plaques with central dusky discolouration. He had no oral or conjunctival ulceration.
A diagnosis of erythema multiforme was made. He was referred to the dermatology service for a
punch biopsy and was discharged home on topical steroids.
Erythema Multiforme
• EM) is a hypersensitivity reaction usually triggered by infections, most commonly herpes
simplex (HSV).
• It presents with a skin eruption characterised by a typical target (iris) lesion.
• There may be mucous membrane involvement.
• It is acute and self-limiting, usually resolving without complications.
• Erythema multiforme is divided into major and minor forms, and is now regarded as distinct
from Stevens Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN).
Who gets Erythema Multiforme?
• Erythema multiforme most commonly affects young adults (20-40 years of age), however all
age groups can be affected.
• There is a male predominance but no racial bias.
• There is a genetic tendency to EM.
What Causes Erythema Multiforme?
• Infections
• Infections are probably associated with at least 90% of cases of EM.
• Herpes is the most common trigger for causing EM; usually herpes labialis (cold sore
on lip) and less commonly genital herpes. HSV-1 infection is more commonly
associated than HSV-2. The herpes infection usually precedes the skin eruption by 314 days.
• Mycoplasma pneumonia is the next most common infectious trigger.
• Less commonly
o Parapoxvirus (orf is an infection from sheep & milker’s nodules are from
milking cows)
o Herpes varicella zoster (chickenpox and shingles)
o Adenovirus
o Hepatitis viruses
o HIV
o CMV
o Viral Vaccines
o Tinea
• Drugs
o Medications are probably an uncommon cause (<10%) of EM.
o Drugs that have been reported to trigger EM include barbiturates, non-steroidal antiinflammatory drugs, penicillins, sulphonamides, phenothiazines and anticonvulsants.
Clinical Features.
• Constitutional Symptoms – usually absent, however in EM Major there may be fever, chills,
weakness and arthralgia.
• Skin lesions
o Rapid onset over 24 hour period – anywhere from several to hundreds of lesions
o
Start on dorsal surface of hands and feet and spread to trunk.
o
Upper limbs are more commonly affected than the lower.
o
Often grouped on elbows and knees
o
Lesions may be itchy or have a burning sensation
o
Initial lesions are sharply demarcated, round, red/pink and flat (macules)
o
Lesions then become raised (papules) and gradually enlarge to form plaques up to
several centimetres in diameter.
o
The centre of the papule/plaque darkens in colour and develops surface (epidermal)
changes such as blistering or crusting.
o
Lesions usually evolve over 72 hours
o
The typical target (iris) lesion of EM has a sharp margin; regular round shape and
three concentric colour zones, central is dusky or dark red.
o
The eruption is polymorphous (many forms), hence the ‘multiforme’ in the name.
Editor: Peter Wyllie
o
Lesions show the Köbner (isomorphic) phenomenon, meaning they can develop at
sites of preceding (but not concurrent or subsequent) skin trauma.
o
Mucosal lesions, if present, typically develop a few days after the skin rash begins.
o
Mucosal changes, if present, consist initially of redness of the lips and inside cheek.
Sometimes blisters develop and quickly break to form erosions and ulcers.
o
In EM major, one or more mucous membranes are typically affected, most often the
oral mucosa.
o
Other mucosal sites affected may include the eye, airways and gastrointestinal tract.
o
Mucosal lesions consist of swelling and redness with blister formation. The blisters
break quickly to leave large, shallow, irregular shaped, painful ulcers that are covered
by a whitish pseudomembrane.
o
Typically the lips are swollen with haemorrhagic crusts.
o
With mycoplasma pneumonia, the mucous membranes may be the only affected
sites (mucositis).
o
Erythema Multiforme can be recurrent with multiple episodes per year for many
years. This is believed to be nearly always due to HSV-1 infection.
How is the diagnosis made?
• Erythema multiforme is a clinical diagnosis although skin biopsy may be required to exclude other
conditions.
• Other tests may be done looking for infections commonly seen in association with EM such
as for Mycoplasma pneumoniae
Treatment:
• For the majority of cases, no treatment is required as the rash settles by itself over several weeks
without complications.
• Directed therapy for specific infections (aciclovir for herpes simplex, macrolides for
mycoplasma)
•
Drug cause, cease offending medication.
•
Supportive / symptomatic treatment (antihistamines, analgeic mouthwashes). EM Major may
require admission for parenteral fluids.
•
The role of oral steroids remains controversial, as no controlled studies have shown any
benefit. However for severe disease 0.5 - 1mg/kg/day Prednisone is often commonly used.
•
Recurrent EM is usually treated initially with continuous oral acyclovir for 6 months, even if
HSV has not been an obvious trigger for the patient's EM. This has been shown to be
effective in placebo-controlled double blind studies. However EM may recur when the
acyclovir is ceased. Other antiviral drugs such as valciclovir (500-1000mg/d) and famciclovir
(250mg twice daily) should be tried if aciclovir has not helped.
•
Other treatments (used continuously) that have been reported to help suppress recurrent EM
include dapsone, antimalarial drugs, azathioprine
Outlook?
o Erythema multiforme usually resolves spontaneously without scarring over 2-3 weeks for the
EM minor form, and up to 6 weeks for EM major.
o EM does not progress to SJS/TEN.
Editor: Peter Wyllie
•
•
There may be residual mottled skin discolouration.
Significant eye involvement in EM major may result in ocular complications including
blindness, as seen with SJS/TEN.
References- we’ve mentioned this one before but a great on-the-floor resource: www.dermnet.org.nz
DERMATOLOGY NOMENCLATURE – how do I describe that rash?
While we’re on the dermatology bandwagon, here’s something worth repeating - a reminder on how
to describe common skin lesions. 1cm seems to be the magic number in dermatology now.
Lesions
Description
Flat lesions
Macules
Patch
A well-delineated, flat discolouration of the skin <1cm + - of any colour.
A well-delineated, flat discolouration of the skin >1cm of any colour.
Elevated lesions
Papule
Plaque
Nodule
An elevated solid lesion up to 1cm in diameter; colour varies; papules may
become confluent and form plaques.
A circumscribed, elevated, superficial, solid lesion more than 1cm in
diameter.
A circumscribed, elevated, solid lesion more than 1cm in diameter; same as
papule but deeper involvement in the dermis or subcutaneous tissues.
Clear, fluid filled lesions
Vesicle
A circumscribed collection of free fluid up to 1cm in diameter
Bulla
A circumscribed collection of free fluid more than 1cm in diameter
Pustule
A circumscribed collection of leukocytes and free fluid that is variable in size
Deposits of Blood
Petechiae
Purpura
Miscellaneous
Scales
Crust
Erosion
Ulcer
Fissure
Burrow
Atrophy
Telangiectasia
Lichenification
Excoriations
Eschar
Wheal
Editor: Peter Wyllie
A circumscribed deposit of blood less than 1cm in diameter
A circumscribed deposit of blood greater than 1cm in diameter
Excess dead epidermal cells that are produced by abnormal keratinisation
and shedding.
A collection of dried serum and cellular debris.
A focal loss of epidermis. Heal with no scarring.
A focal loss of epidermis and dermis. Heal with scarring.
A linear loss of epidermis and dermis with sharply defined, nearly vertical
walls
Linear lesions produced by the infestation of skin and formation of tunnels by
scabies, mites or cutaneous larva migrans.
Thinning or absence of the epidermis or subcutaneous fat.
Permanent dilatation of superficial blood vessels in the skin and may occur
as isolated phenomena or as part of a generalized disorder, such as ataxia
telangiectasia.
Thickening of the epidermis seen with exaggeration of normal skin lines. It is
usually due to chronic rubbing or scratching of an area
Traumatized or abraded skin caused by scratching or rubbing.
Hard plaque covering an ulcer implying extensive tissue necrosis, infarcts,
deep burns, or gangrene
A firm oedematous plaque resulting from infiltration of the dermis & epidermis
with fluid; wheals are transient and may last only a few hours – includes
urticaria. (Angioedema is caused by the same or similar pathologic
alterations as urticaria but it involves the deep dermis and subcutaneous
tissue. An area involved with angioedema therefore has swelling as the
prominent manifestation, and the appearance of the skin itself may be
normal. Because angioedema occurs in deeper skin layers, where there are
fewer mast cells and sensory nerve endings, the lesions have little or no
associated pruritus, and the swelling may be described as painful or burning.
Urticaria may occur on virtually any part of the body, whereas angioedema
(in the absence of hives) often involves the face, tongue, extremities, or
genitalia. In contrast to other forms of oedema, angioedematous swellings do
not characteristically occur in dependent areas, are asymmetrically
distributed, and are transient.
Description
Annular
Discrete
Clustered
Confluent
Dermatomal
Follicular
Guttate
Ring shaped (e.g. tinea corporis)
Separate.
Grouped together (e.g. herpes simplex or insect bites)
Join or run together
Lesions follow a dermatome (e.g. zoster).
Involving hair follicles
Nothing to do with the size of the persons girth but the lesions look as though
someone took a dropper and dropped this lesion on the skin (e.g. guttate
psoriasis).
Target Lesions
Central colour change
Koebner Phenomenon Appearance of lesions along a site of injury.
Linear lesions
Occur in a line or band-like configuration.
Multiform lesions
Variety of shapes.
Reticular
Net-like lesions - seen in a variety of circumstances; (e.g., very commonly in
newborns as cutis marmorata, or with livedo reticularis)
Serpiginous
Wander as though following the track of a snake.
Scarlatiniform
Has the pattern of scarlet fever- innumerable small red papules that are
widely and diffusely distributed. Characteristic of Scarlet fever, but can also
be seen in conditions such as Kawasaki disease, non-specific viral infections,
or drug reactions.
Morbilliform
A rash that looks like measles - macular lesions that are red and are usually
2-10 mm in diameter but may be confluent in places. Seen in measles +
Kawasaki disease, and drug reactions.
Satellite Lesions
Often used to describe candidiasis in which a beefy red plaque may be found
surrounded by numerous, smaller red macules located adjacent to the body
of the main lesions.
Nummular / discoid
Rounded or oval shaped
Acral
Means it affects distal portions of limbs (hand, foot) and head (ears, nose).
Erythroderma
When a skin condition affects the whole body or nearly the whole body,
which is red all over
Flexural
distribution involving the flexures, (i.e. the body folds- also known as
intertriginous distribution)
JOKE / QUOTE OF THE WEEK
On their honeymoon, the blonde bride slipped into a sexy nightie and with great anticipation
crawled into bed, only to find her husband had settled down on the couch.
When she asked him why he was apparently not going to make love to her, he replied, ' It's Lent.'
In tears, she sobbed, 'Well, that is the most ridiculous thing I've ever heard!
'Who did you lend it to, and for how long?'
Editor: Peter Wyllie
Editor: Peter Wyllie