Friday, September 17, 2021

A Case of Toxic Epidermal Necrolysis treated with Etanercept

Presented by Dr, Henry Foong
Ipoh, Malaysia

A patient in his 50s with a history of non-Hodgkin lymphoma was admitted to our local hospital because of fever and generalised skin eruptions for 5 days.  He had developed conjunctivitis, painful mouth ulcers, and painful genital erosions. He was on cozaar and simvastatin which was started about 3 weeks ago.  He denied taking any new oral medications including OTC supplements. 

On Examination: He had generalised dusky coloured targeted macules on the trunk, extremities including palms and soles.  Some of the lesions appeared to be peeling. Bilateral conjunctival redness were noted in both eyes.  There were superficial erosions on the lips, tongue and inner buccal cavity. superficial erosions were also noted on the glans penis. His body surface area (BSA) is estimated to be 45%. (Fig 1 and 2)


Fig 1

Fig 2
 

A diagnosis of Toxic Epidermal Necrolysis was made. 

A skin biopsy was performed.

Pathology: Section shows prominent spongiosis with focal parakeratosis. The epidermis shows focal necrotic keratinocytes and intra-epidermis lymphocytes. There is zonal epidermal necrosis in the center of the biopsy, associated with hemorrhage and a perivascular lymphocytic cuffing of the superficial dermal vessels. The dermis shows mild perivascular neutrophils infiltration. There is no atypical lymphocyte or malignancy seen. The deeper dermis and subcutaneous fat are normal. Extensive lichenoid dermatosis consistent with erythema multiforme. No atypical lymphocyte seen. (Fig 3)
 

Fig 3

Both the antihypertensive and statin ( and all other non essential medications) was withheld. He was initially treated with IV fluids, IV hydrocortisone 200mg qid, oral toilet with sodium bicarb gargle, dilute KMNO4 wash daily, soft paraffin wax as moisturisers.  His blood counts and biochemistry were unremarkable except for raised urea, creatinine and low bicarbonate.  His SCORTEN* score was calculated to be 5 out of 7. While waiting for s/c etanercept 50mg  to arrive, he was treated with IvIg 25 gm daily and IV hydrocortisone 100mg did as an interim measure for 2 days.  He responded well to treatment and his skin begins to heal on day 2 of s/c etanercept. 

 
The use of TNFa inhibitors was first described in the treatment of SJS/TEN in 2002 using infliximab. (1)  It was believed to be the T cells secreting TNFa induced epithelial cell death through granulysin, nitric oxide FasL pathway, CCL 27 and T reg cells.  In 2014, Paradisi described the successful use of etanercept for TEN in JAAD. (2) A good systemic review of the biologic TNF a inhibitors can be found in JDD in 2019. (3)
 
In this case study, we described the successful use of etanercept in an ill patient with TEN.
1.  Which is preferable? IV IgG vs oral cyclosporin vs s/c etanercept
2.  Is there any role of systemic corticosteroids in SJS or TEN?
3. If s/c etanercept is preferable, what would be the interim treatment while waiting for the medication to arrive?  None of our local Malaysian hospitals keep s/c etanercept in their drug store.

References:
1. Fisher. Anti-TNFa (Infliximab) in the treatment of a patient with TEN. Br J Dermatol 2002:146:707-709
2. Paradisi et al. Etarnercept therapy for TEN. J Am Acad Dermatol 2014: 71: 278-283
3. Zhang S, Tang S, Li S, Pan Y, Ding Y. Biologic TNF-alpha inhibitors in the treatment of Stevens-Johnson syndrome and toxic epidermal necrolysis: a systemic review. J Dermatolog Treat. 2020 Feb;31(1):66-73. doi: 10.1080/09546634.2019.1577548. Epub 2019 Feb 19. PMID: 30702955.
 
SCORTEN Score is  Severity of Illness Score for Toxic Epidermal Necrolysis.  See Wiki and scroll down.