Introduction:
Drug induced cutaneous reactions can be mild or severe based on
morbidity and mortality it possesses. While drug exanthem is the most
common skin reaction to medications, it’s not uncommon for the serious
cutaneous drug reactions to ensue [1].
Steven-Johnson syndrome and toxic epidermal necrolysis are idiosyncratic
drug reactions, which are type IV hypersensitivity reaction triggered by
drug antigens in keratinocytes that induces T-cell mediated cytotoxic
reaction[2]. SJS is characterized by skin lesions
that can range from erythematous or purpuric papules to flaccid bullae
and confluent erosions and can affect both mucosal and non-mucosal
surfaces, predisposing patient to super added infections and toxic
state. This potentially lethal drug reaction if involves >
10% of body surface area is called SJS syndrome while when involving
more than 30% of BSA is called Toxic epidermal necrolysis[3].
Sulfonamides, nonsteroidal anti-inflammatory drugs, anticonvulsants and
antibiotics are the commonly implicated drugs in SJS and TEN. And among
antiepileptics, carbamazepine (CBZ) is one of the culpable agents
implicated[4]. The 10-keto analogue of
carbamazepine, Oxcarbazepine (OXC) has better safety profile compared to
predecessor and hence preferred in elderly and children. The
Stevens-Johnson Syndrome, an adverse drug reaction was found to be less
common with oxcarbazepine and there were only few case reports in the
literature[1,2,5-7]. Most of Adverse drug
reactions are under-reported, thus resulting in no evaluation of the
expectedness, severity and causality of these
reactions[8]. Thus, it is important to report such
drug reactions as it will further help in estimating the incidence of
oxcarbazepine induced SJS. Here we are reporting a case of oxcarbazepine
induced Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN)
Overlap.
Case report :
A 76-year-old female was brought to emergency department of AIIMS, with
Chief complaints of dusky red macules all over body, including perioral
skin with erosion in buccal and palatal mucosa with white exudate and
erosions on bilateral eyelids. She has had history of insomnia and
agitation one month back for which escitalopram, lorazepam and
amantadine were prescribed, which was taken for a week and was
discontinued because of worsening of agitation, increased talkativeness
and psychomotor activity. And after two weeks, she was further taken to
a private practitioner for the same symptoms and was prescribed
oxcarbazepine in 600mg dosage, following which there was resolution of
symptoms. Post 1 week of starting of the above medication she developed
mild fever, macular rash over trunk with perioral rashes. The next day
the patient’s attendants noticed blister formation on sides of mouth and
macular eruptions on thigh, spreading to all over body and face with
redness of eyes and painful mouth ulcers with difficulty in eating food
over the next 3 days. For which they discontinued the medication and
visited the casualty and patient was admitted. Dermatological
examination revealed 20 percent body surface area involvement with
erosions in oral mucosa, bilateral eyelids, back and confluent macular
eruptions over trunk and thighs as shown in figure 1,2& 3. She had no
history of any allergies, drug reactions. There was no associated
swelling of the joints or any other tissue involvement. There was mild
local raise of temperature with stable vitals and other systematic
examination was within normal limits. There was no history of any recent
use of cosmetic products or any local application of cream/lotions on
face or food changes or any other medication. Laboratory investigations
showed significantly anaemia, increased ESR, raised blood glucose
levels, neutrophilia, lymphocytopenia, normal liver function tests and
renal function tests but low serum sodium.
During the course in hospital, patient was started on cyclosporin and
tapering dose of dexamethasone. She had an episode of disorientation
which was managed with low dose haloperidol. She was given adequate
antibiotic coverage with blood sugar and pain management. She responded
well to treatment and was discharged on 5th day of
admission with dried erosions and healing lesions.
This case had a Naranjo score of +8 based on available clinical
information that points towards probable adverse drug reactions as we
did not attempt to re-challenge with the oxcarbazepine for any
reappearance of the rash[9]. It was an ADR that
required admission increasing length of stay in hospital with the
treatment and stoppage of suspected drug as per assessment with
Hartwig’s severity scale that revealed a level 4
severity[10]. The WHO-UMC criteria for causality
revealed this ADR as being probable/likely due to oxcarbazepine
intake[11]. A SCORTEN scoring system for SJS/TEN
predicts the probability of hospital mortality was calculated within the
first 24 hours of admission revealed a score of 3(Age>40,
epidermal detachment >10% at the admission, blood glucose
>300mg/dl) [12].