Derm: Stevens-Johnson Syndrome: Free MSRA Podcast

🧑‍⚕️ FREE MSRA PODCAST – Stevens-Johnson Syndrome (SJS): Emergency Recognition & Management
🔥 Your essential, high-yield crash course on SJS—perfect for the MSRA and real-life practice. Listen up for life-saving revision!

Key Learning Points

📌 Definition & Spectrum
• Stevens-Johnson Syndrome (SJS) is a rare but severe mucocutaneous reaction—most often to medications, sometimes infections
• Marked by blistering rash, widespread skin detachment, and mucosal involvement
• Part of the SJS-TEN spectrum (differentiated by % body surface area involved)

🚩 Causes & Risk Factors
• Drugs: Sulphonamides, anticonvulsants (carbamazepine, lamotrigine), allopurinol, NSAIDs
• Infections: Mycoplasma pneumoniae, herpes simplex, influenza (especially in children)
• Genetic predisposition (HLA alleles), HIV infection, previous SJS, immunosuppression

🩺 Clinical Features
• Prodrome: Fever, malaise, sore throat, then sudden widespread erythematous/purpuric rash
• Blistering and epidermal detachment, positive Nikolsky sign
• Severe, painful mucosal erosions: mouth, eyes, genitals
• Lesions start on trunk, spread to limbs, palms, soles
• May rapidly progress to multi-organ involvement

🧠 Mnemonic: SJS
S: Stop the drug immediately
J: Junctions (mucosal) involved
S: Sloughing of skin

🔬 Diagnosis & Classification
• Clinical diagnosis is key—history of new drug exposure or recent infection
• Biopsy confirms keratinocyte necrosis (for unclear cases or to rule out differentials)
• Classify:

• SJS: <10% BSA

• SJS/TEN overlap: 10–30% BSA

• TEN: >30% BSA

⚡ Differential Diagnoses
• Toxic epidermal necrolysis (TEN)
• Erythema multiforme
• Bullous pemphigoid, pemphigus vulgaris
• Staphylococcal scalded skin syndrome (SSSS)
• Drug-induced rashes

🏥 Investigations
• FBC, U&Es, LFTs, CRP/ESR, coagulation, cultures
• Skin swabs, serology if infection suspected
• SCORTEN score predicts severity/mortality

💊 Management (UK/NICE)
• Immediate withdrawal of offending drug—non-negotiable
• Admit to ITU/burns unit for specialist supportive care
• IV fluids, wound care, analgesia, nutritional and eye support
• Monitor for sepsis, multi-organ failure
• Steroids/IVIG: Specialist advice only—controversial role

🌟 Prognosis & Complications
• Mortality: SJS 5–10%, TEN >30%
• Long-term: Skin scarring, pigment changes, strictures, chronic eye disease, blindness
• Acute: Sepsis, dehydration, respiratory failure, DIC, multi-organ failure

📎 More MSRA Revision for Stevens-Johnson Syndrome:
📝 Revision Notes: https://www.passthemsra.com/topic/stevens-johnson-syndrome-revision-notes/
💬 Flashcards: https://www.passthemsra.com/topic/stevens-johnson-syndrome-flashcards/
🧠 Accordion Q&A: https://www.passthemsra.com/topic/stevens-johnson-syndrome-accordion-qa-notes/
🚀 Rapid Quiz: https://www.passthemsra.com/topic/stevens-johnson-syndrome-rapid-quiz/
🧪 Full Quiz: .css-j9qmi7{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:row;-ms-flex-direction:row;flex-direction:row;font-weight:700;margin-bottom:1rem;margin-top:2.8rem;width:100%;-webkit-box-pack:start;-ms-flex-pack:start;-webkit-justify-content:start;justify-content:start;padding-left:5rem;}@media only screen and (max-width: 599px){.css-j9qmi7{padding-left:0;-webkit-box-pack:center;-ms-flex-pack:center;-webkit-justify-content:center;justify-content:center;}}.css-j9qmi7 svg{fill:#27292D;}.css-j9qmi7 .eagfbvw0{-webkit-align-items:center;-webkit-box-align:center;-ms-flex-align:center;align-items:center;color:#27292D;}

Episode Transcript

(00:00):
Welcome to the Deep dive. Today we're taking a close look
at a condition you really need to know about, Stevens Johnson
Syndrome or SJS. If you're in medicine,
especially if you're prepping for something like the MSRA
exam, this is definitely high yield stuff.
It demands your attention because while it's rare, it's
incredibly serious. That's absolutely right.

(00:22):
Our aim here is really to, you know, cut through the complexity
and pull out the essential knowledge on SJS, right?
What it is, why it happens, how to spot it, how it's managed,
and what the potential outcomes are.
Think of this as your focused, efficient revision session.
Perfect. Yeah, it's one of those
diagnosis that when you see it, you need to act fast.

(00:42):
So let's dive right in and unpack what SJS is, you know, at
its core, OK? Fundamentally, Stevens Johnson
Syndrome is a severe life threatening reaction.
It primarily affects the skin and the mucous membranes.
It's rare, but when it hits, it hits hard.
So what are the defining features then?
What makes it stand out from other rashes or reactions?
Well, the hallmarks are a wide red blistering rash, and this is

(01:04):
crucial, significant involvementof the body's mucous membranes.
And almost always this is triggered by something external,
most commonly medications or sometimes infections.
So it's not just affecting the skin then?
Where else does it show up? Oh, definitely not just the skin
surface. It involves mucous membranes
pretty much everywhere. The mouth, the eyes, the
digestive tract, genitals, respiratory tract.

(01:27):
Wow. Yeah, this widespread
involvement is why it can rapidly lead to systemic
complications and even multi organ failure.
That multi system impact really underscores how serious it is.
How common are we talking globally or, you know,
specifically in the UK? In the UK, we're looking at an
incidence of roughly one to two cases per million people per
year. So yes, it's rare, very rare,

(01:48):
very rare. And the mortality rate for SJS
itself is less than 10%. But that statistic doesn't tell
the whole story because survivors often face significant
long term health issues. OK.
And how do doctors classify thiscondition?
Is it like a straightforward or allergic reaction?
It's definitely more complex than a simple allergy.
It's classified as an immune complex mediated

(02:10):
hypersensitivity disorder, right?
What's really critical to understand is that SJS is
actually part of a spectrum of severity.
At the milder end you might see things that overlap with
erythema multiform, and at the most severe end you have toxic
epidermal necrolysis or 10. OK, so SJS and 10 are sort of on
the same continuum. Exactly.

(02:30):
They stem from the same core problem, a process where the top
layer of skin, the epidermis andalso the mucous membranes, they
start to detach from the layers underneath.
The distinction between SJSSJ, S10 overlap and 10 is mainly
based on the percentage of body surface area where that
detachment is happening and alsothe type of skin lesions you
see. Can you just quickly clarify

(02:51):
those categories based on detachment?
That sounds like a key differentiator.
Sure. So when the detachment is less
than 10% of the body surface area and you primarily see these
sort of raised atypical target like lesions, that's typically
SJS. OK, 10%.
Yeah, if the detachment is between 10% and 30%, it's
classified as SJS 10 overlap. Got it.
Once you get above 30% detachment, pretty much

(03:13):
regardless of the lesion type, you're in the realm of toxic
epidermal necrolysis or 10. Right, 10 is 30%.
Exactly, and there's also erythema multiform major, which
is often considered part of thisgroup.
Less than 10% detachment, but different lesion types, often
more classic targets. Got it.
So it's really about the scale of that detachment.
Now, what actually triggers thisthis devastating immune system

(03:35):
response? Well, the primary drivers are
indeed the body's immune system overreacting to specific
external agents, most commonly medications or in some cases,
infections. We also know genetics play a
pretty significant role in determining who might react this
way. OK, let's talk medications.
Which ones are the most notorious culprits?
The ones someone revising reallyneeds to remember.

(03:57):
Yeah, this is definitely high yield information.
The big categories include antibiotics, particularly the
sulfa drugs like sulfamethoxazole.
Sulfa drugs? Yep.
Anticonvulsants are another major groupthink.
Carbamazepine, lamotrigini, phenobarbital, phenitoin, OK
anicides, especially the oxycam class like meloxicam.
They're linked. Allopurinol is a really well

(04:18):
known trigger. Allopurinol.
Right. Antivirals like nivirapine and
abacavir are also significant, and then less commonly things
like sertraline, bupropion, certain antifungals and
salicylates can be involved too.That's quite a list of common
drugs. What about infections?
Infections are also triggers, yeah, but there's a bit of a
pattern, especially with children.
In kids, viral infections are more frequent culprits.

(04:41):
Things like influenza, mumps, measles, herpes simplex, Epstein
Barr virus, right adults. While infections like
mycoplasma, pneumonia, HSVHIV orGroup A strep can trigger it,
unpredictable drug reactions aremore often the 'cause.
There's also an association noted with some immunizations
like measles and hepatitis B. So when you see a patient

(05:02):
presenting with the signs a really meticulous drug history,
looking for anything new they started is absolutely essential.
It's arguably the single most important question you can ask
initially. Have they started any new
medication prescription or over the counter or had a recent
infection? Thinking about those key drug
categories we just mentioned canhelp narrow down the

(05:23):
possibilities pretty quickly. Makes sense beyond the trigger
itself, who is most at risk of developing SJS if they are
exposed? Yeah, Certain patient
populations definitely have a higher propensity, those with
underlying viral infections, particularly HIV.
Individuals with HIV have a significantly higher risk of
developing SJS 10 compared to the general population.

(05:45):
Why Really. Yeah, other immunocompromised
states also increase risk, like patients undergoing
chemotherapy, organ transplant recipients, or those with
autoimmune diseases like SLE. And does a person's past history
or family history matter? Yes, big time.
If you've had SJS before, especially linked to a specific
medication, you have a much higher risk of it happening

(06:06):
again if you're ever re exposed to that drug.
Right. Avoid it for life.
Exactly, and having a family history of SJS can also suggest
an increased genetic susceptibility.
Genetics. This is where those HLA types
come in, isn't? It exactly.
This is a fascinating piece of the puzzle.
Specific human leukocyte antigenor HLA alleles are strongly
linked to SJS triggered by certain drugs, often in specific

(06:30):
populations, like which ones? For instance, in people of Han
Chinese origin, the HLA B15O2 allele is strongly associated
with carbamazepine induced SJS, HLA B15O8IS linked to
allopurinol induced SJS, and HLAB57-O 01 is associated with
abacavir induced SJS 10, particularly in HIV patients.

(06:52):
So is this genetic link why sometimes screening is
recommended before prescribing certain drugs?
Precisely in populations known to have a higher prevalence of
these specific HLA alleles, screening patients before
starting medications like carbamazepine or abacavir can be
a vital preventative measure to avoid potentially triggering
SJS. Right, let's switch gears
slightly and talk about what's actually happening inside the

(07:13):
body. The pathophysiology.
How does this immune attack unfold at like a cellular level?
OK, think of your immune system as your body's security system
constantly patrolling for threats.
In SJS, that system gets confused.
It mistakenly identifies your own skin and mucous membrane
cells as foreign invaders and launches a massive attack
against them. Like friendly fire.

(07:35):
Exactly, but on a devastating scale.
It's an immune mediated process involving a complex interplay of
that genetic background, activation of immune cells and
the presence of the triggering drug or infection.
OK, this leads to an inflammatory cascade which
basically signals the skin cells, the keratinocytes, to
undergo programmed cell death orapoptosis.

(07:56):
So the cells essentially self destruct.
That's the outcome. And as these skin cells die off,
the connections holding the epidermis to the underlying
layers breakdown. This causes that top layer to
detach much like, well, like wallpaper peeling off a damp
wall OK, resulting in those characteristic blisters and raw,
painful erosions. Wow, thinking of it like peeling
wallpaper is a vivid if slightlyterrifying analogy.

(08:20):
Given how it presents with rash and blistering.
I imagine there's a long list ofother conditions that could be
mistaken for, especially early on.
What are the key differential diagnosis?
Yeah, this is absolutely crucialfor anyone needing to diagnose
this, especially under pressure,because SGS can look like many
other things. You need to consider a whole
range of possibilities, right? Of course, toxic epidermal

(08:41):
necrolysis TEN is top of the list, being part of the same
spectrum, but you also need to think about things like erythema
multiform, especially EM, major acute generalised xanthematous
pestilosis or AGP. Autoimmune conditions like bolus
pemphigoid or pemphigus vulgaris.
Severe reactions that can look similar, like bolus phototoxic

(09:01):
reactions or exfoliative dermatitis, sometimes called
erythroderma. Even infections that cause skin
issues like staphylococcal scalded skin syndrome, SSSS,
which is really important to distinguish because it's
bacterial and needs different treatment.
Even rarely Lyme disease. And of course, simple
maculopapular drug rashes, though they usually don't have

(09:23):
that severe blistering and mucosal involvement.
That's quite a challenging list.It is distinguishing SJS from
these, particularly 10 and erythema multiform, is vital
because the management and prognosis really differ.
OK. So just a quick recap on the
numbers before we move to presentation.
We mentioned the UK incidents, but are there any other key
epidemiology points? Just to reiterate, yeah, it's

(09:45):
one to two cases per million peryear in the UK.
It is generally more common in adults with perhaps a slight
female predominance. Right.
But the most significant risk factor from an epidemiological
standpoint is undoubtedly HIV, the infection, which increases
the risk substantially. And while it can occur at any
age, most patients are between 10 and 30 years old.
Younger children who do get it tend to have a higher mortality

(10:08):
risk. OK, let's get into the clinical
picture then. How does SJS actually present?
What would a patient complain ofand what would a doctor see?
Right. It typically doesn't start with
the full blown rash. Often the initial symptoms are
quite nonspecific, almost like abad case of the flu.
Like a prodrome? Exactly a prodrome.
Patients might feel generally unwell, have a fever, sore

(10:32):
throat, chills, headache, joint pain, maybe some nausea,
vomiting or diarrhoea. This phase can last a few days,
so. It could be easily missed
initially. Yes, the prodromal phase can be
tricky, but then things progressrapidly.
The Miko cutaneous lesions develop quite suddenly, and a
key point is they're usually notitchy, which helps differentiate

(10:53):
them from common allergic rashes.
Not itchy. OK, describe the skin lesions
themselves. They can start anywhere on the
body, but often begin on the trunk and proximal limbs,
sometimes involving palms and soles.
Early on they might start as flat red areas, Mccools or
slightly raised bumps, papules that can then develop vesicles
or bully those large blisters right?

(11:13):
A character but sometimes misleading feature is target
like lesions, although in SJS itself they're more often
described as atypical targets, less well defined, maybe dusky
centres. These blisters then rupture,
leaving raw, painful areas that look a bit like superficial
burns and are really prone to infection.
And there's one physical sign that is a massive red flag for

(11:36):
this condition in 10, right? Yes.
It's called the positive Mikulski sign.
Ah. The Mikulski sign.
What is it exactly? It's when you apply minimal
pressure or gentle friction to seemingly unaffected skin near a
lesion and the epidermis, the top layer blisters or peels away
easily. Wow.
This sign indicates that there is underlying epidermal
detachment, which is the absolute hallmark of SJS 10.

(11:59):
If you elicit a positive Nikolsky sign in a patient with
a widespread rash, you should bethinking SJS 10 immediately.
That sounds incredibly painful and also like a crucial
diagnostic clue. Yeah, you mentioned mucosal
involvement is key. What does that look like in
practise? Yeah, it's almost universal and
often proceeds or occurs simultaneously with a skin rash.
It involves redness, swelling, blistering, ulceration, and

(12:23):
actual tissue death. Necrolysis of the lining of
multiple body cavities. The mouth is almost always
affected with severe painful erosions that make eating,
drinking, even talking incredibly difficult, right?
The eyes are also very frequently involved, causing
painful red eyes, significant discharge, sensitivity to light,
photophobia and inflammation of the eyelids and conjunctiva.

(12:47):
Genital involvement is common, leading to painful urination,
dysuria or difficulty voiding, and the lining of the
respiratory and gastrointestinaltracts can also be affected,
leading to cough, difficulty breathing or severe diarrhoea.
So it's truly attacking the internal linings as well as the
external skin. Absolutely.
That widespread epithelial surface involvement is what

(13:08):
drives many of the severe complications.
OK, let's try and put some of this together into a potential
scenario. Maybe something someone prepping
for an exam might see. Imagine a 25 year old patient
presents the Ed. They felt unwell for a few days
with fever and joint aches. Yesterday they started
developing painful red areas on their body that are now
blistering and they have excruciating sores in their

(13:30):
mouth that are bleeding and their eyes are red and sensitive
to light. On examining their skin, you
notice the top layer seems fragile and easily peels off
with gentle rubbing. What's the most likely
diagnosis? And what's that physical sign
you just elicited? OK.
That presentation with the prodromal symptoms, the painful
blistering rash, the severe multi site mucosal involvement

(13:54):
and that skin fragility. Yeah, that screams Stevens
Johnson syndrome or 10 M right? And that physical sign, the skin
peeling away with gentle pressure, that's the positive
Mikulski sign. Recognising that pattern quickly
is paramount. Right.
So presentation is key for diagnosis, but are there
investigations to confirm it or assess the severity?

(14:14):
Yes, absolutely. SGS is primarily A clinical
diagnosis based on those characteristic features we just
discussed. But investigations are essential
to support the diagnosis, gauge how severe it is and help rule
out some of those look alike conditions we mentioned earlier.
What are the core tests needed? You'll need a range of blood
tests. Definitely a full blood count,
inflammatory markers like ESR and CRP, kidney and liver

(14:35):
function tests, UNES, LFTS, electrolytes, coagulation
studies. Serology for mycoplasma
pneumonia might be sent if that's suspected as a trigger.
A chest X-ray is usually performed.
Clinical photographs are vital for monitoring progression, and
swabs from skin lesions or mucosal sites should be taken
for bacterial and fungal cultures to check for secondary

(14:57):
infections. And how about a skin biopsy?
Is that necessary? A skin biopsy is very important
for confirming the diagnosis, particularly in less clear cut
cases or to rule out differentials like autoimmune
blistering diseases. Right, The biopsy needs to be
taken from an affected area and crucially sent unfixed for
direct immunofluorescence studies DIF which can help

(15:18):
differentiate it from other blistering conditions.
Unfixed for DIF got it. Exactly.
The Histology typically shows programme cell death in the
basal layer of the epidermis, blistering just below the
epidermis and some inflammatory cells.
Is there a scoring system to predict how unwell a patient
might get? Yes, there's a widely used
prognostic score called Scortin or score for toxic epidermal

(15:41):
necrolysis. Scorkson.
Scornton it's calculated within the 1st 24 hours of hospital
admission using 7 clinical and laboratory parameters.
A higher Scornton score predictsa higher risk of in hospital
mortality. OK.
It's a crucial tool for prognosis and really helps guide
the intensity of management required, indicating who needs,
you know, burn unit or intensivecare level support.

(16:03):
So diagnosis made, assessment done with Scorton?
What is the management? This sounds like it requires
immediate intensive care. It is absolutely a medical
emergency requiring immediate hospitalisation, ideally in a
specialised unit like a burns unit or intensive care unit,
right, because the complexity and supportive care needs are
very much like managing a severeburn.
A multidisciplinary team is essential.

(16:25):
What is the single most important non negotiable initial
step in management? The absolute priority, the very
first thing you must do, is immediately discontinue any
suspected causative drug. Right, stop the drug.
If a medication is the likely trigger, stopping it is critical
and directly impacts the outcome.
OK. Drug stopped.
What comes next in terms of supportive care?

(16:46):
Initial management focuses heavily on meticulous supportive
care. This includes establishing IV
access, aggressive fluid resuscitation to replace the
large volume losses from the damaged skin and mucosa.
Seriously think like managing severe burns in terms of fluid
loss. OK, you need to closely monitor
fluid balance. Nutritional support is vital.

(17:09):
Because of the severe oral involvement, patients often
can't eat so a nasogastric tube is usually required.
Makes sense. A urinary catheter is needed if
there's genitor any involvement.You also need to estimate the
body surface area affected, justlike with a burn patient, as
this helps guide fluid management and prognosis.
And for symptom relief, particularly the pain, which
must be immense. Oh, the pain is immense.

(17:31):
Strong analgesia is crucial for the mouth.
Anaesthetic or antiseptic mouthwashes can provide some
relief. Skin care involves gentle
cleansing, application of emollients and antimicrobial
agents to prevent secondary infection.
Eye drops and ointments are essential for ocular care, often
needing involvement from ophthalmology early on.

(17:52):
I've heard debate around the useof systemic corticosteroids or
other immunosuppressants. What's the current thinking on
that? That's right, the use of
systemic cortico strose and other immunomodulatory therapies
like IV Edge is controversial. While they might seem logical to
dampen the immune response, theyalso carry significant risks,
particularly increasing the riskof overwhelming infection in

(18:15):
patients who already have compromised skin barriers and
are often critically ill. Right, makes sense.
So management is increasingly focused on that meticulous,
supportive care rather than systemic immunomodulation,
though specialist advice is always, always needed.
And looking ahead, once a patient recovers, how do you
prevent this from happening again?
Crucial prevention If a causative drug was identified,

(18:37):
the patient must be advised to avoid that medication for life.
For life. Absolutely, they should be given
clear written information about the drug and encouraged to
inform any healthcare provider they see and if genetic links
were identified. Informing family members about
potential susceptibility is alsoimportant.
It really does sound like managing a severe burn patient.

(18:58):
Intensive supportive care, Fluidbalance, pain control, infection
prevention, nutrition. That's a very good analogy to
keep in mind for the management principles.
The damaged skin barrier and thesystemic nature create very
similar challenges. Shifting to the outlook then,
what's the prognosis for someonewho gets SJS?
Well, prognosis varies significantly depending on the

(19:19):
severity, particularly the percentage of body surface area
involved and how quickly that offending drug has stopped.
The overall mortality rate is somewhere between 5% and 15%.
As we noted earlier, it's maybe up to 10% for SJS itself.
But for the more severe 10 N, the mortality rate is
significantly higher. We're talking at least 30%.
Wow 30% for 10 and even for survivors there can be

(19:41):
significant long term issues. Absolutely.
Survival is definitely not always a full return to baseline
health. Many survivors face lasting
complications. Like what?
These can include chronic skin problems like scarring, changes
in pigmentation, you know, lighter or darker patches, and
increased sensitivity. Nailed dystrophy problems with

(20:02):
nail growth is common. Mucosal issues can persist,
leading to chronic dryness, erosions, or even strictures in
the mouth, oesophagus, or genitals.
And ocular complications are particularly devastating,
ranging from chronic dryness andlight sensitivity to corneal
ulceration and, in severe cases,permanent visual impairment or
even blindness. That really highlights the

(20:24):
potential for severe morbidity even after recovery.
What are some of the other potential serious complications
that could arise during or afterthe acute phase?
Yeah, beyond the skin's risk of secondary bacterial infections
leading to sepsis, the complications really affect
multiple organ systems. Respiratory issues are common
and serious, including pneumonia, bronchial obstruction

(20:45):
from slob mucosa, and even respiratory failure.
Cardiac problems like myocarditis can occur.
While less common, acute kidney injury or acute tubular necrosis
is a possibility. Mild liver inflammation is
sometimes seen. Gastrointestinal involvement can
lead to severe diarrhoea or longterm esophageal strictures, and

(21:05):
the genitorinary and ocular complications we've already
highlighted can be severe and chronic.
And the really critical, life threatening ones.
Well, patients are at risk of severe dehydration and
malnutrition. Due to that mucosal involvement,
they can develop shock, progressto multi organ failure, develop
blood clots, thromboembolism, ora severe clotting disorder
called disseminated intravascular coagulation or

(21:26):
DIC. DIC right?
And we can't forget the significant psychological trauma
this experience inflicts. Also the formation of pseudo
membranes, these thick abnormal layers of tissue on damaged
mucosal surfaces can lead to scarring and long term
dysfunction in various organs. It really is a systemic
catastrophe triggered by that initial immune reaction.

(21:48):
It truly is. It's a devastating condition
affecting epithelial surfaces Pretty much throughout the body.
We've covered a lot of ground onStevens Johnson Syndrome today,
defining what it is, exploring its triggers and risk factors,
understanding the pathophysiology, recognising the
clinical signs including that crucial Mikulski sign, outlining
investigations in management anddiscussing the challenging

(22:09):
prognosis and potential complications.
Yeah, understanding the spectrumof disease, recognising it early
based on the clinical presentation and knowing the
absolute critical initial steps stopping the offending drug is
paramount for managing this medical emergency.
We really hope this deep dive has given you a clear high yield
understanding of Stevens JohnsonSyndrome for your revision.

(22:31):
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