Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN)

Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) represent severe skin reactions that can be triggered by many causes, mainly by medications, and can be characterized by a spectrum of severity ranging from SJS, the milder form, to the more severe TEN. Initially considered distinct entities, they are now understood as part of a continuum. Symptoms typically begin with fever and flu-like manifestations, followed by rapid onset of skin blistering and peeling skin to severe burns, primarily affecting areas like the face and chest, then spreading across the body. The slothing of the skin and the concurrent mucous membrane damage complicates the condition, potentially leading to life-threatening outcomes due to fluid loss, infection susceptibility, and systemic complications such as pneumonia, sepsis, and organ failure.

Mortality rates vary significantly: approximately 10% for SJS and up to 50% for TEN, with survivors often facing long-term issues like skin pigmentation changes, dry skin, abnormal sweating, hair loss, and nail abnormalities. The incidence ranges from two to seven cases per million annually, with SJS more prevalent than TEN and a higher occurrence in older individuals, women, and those with HIV.

Medications implicated in triggering SJS/TEN include anticonvulsants (e.g., lamotrigine, carbamazepine), allopurinol, sulfonamides, certain antibiotics (e.g., penicillin), and others. Genetic predisposition, specifically certain human leukocyte antigen (HLA) types, increases susceptibility, underscoring the importance of familial awareness and cautious medication use.

Diagnostic evaluation employs the SCORTEN system, which assesses criteria like age, malignancy, heart rate, and biochemical markers to predict mortality risk. Management begins with discontinuing the offending agent upon suspicion or confirmation through tools like the ALDEN algorithm. Supportive care in specialized units—such as ICUs or burn units—focuses on fluid resuscitation, temperature regulation, pain control, infection prevention, and meticulous skin and mucosal care. There is an uncertainty among some treatment options, one being the use of steroids. In some cases, systemic corticosteroids may be considered, though their efficacy remains debated.

The pathophysiology involves a Type IV hypersensitivity reaction mediated by T cells, particularly CD8+ cells, triggering cytotoxicity and keratinocyte death, leading to blister formation and skin detachment. As a Type IV hypersensitivity reaction, this is seen as much more severe than a simple allergic reaction and requires quick treatment. Furthermore, early recognition within weeks of medication initiation is crucial, as prompt intervention can mitigate progression and improve outcomes.

Long-term sequelae management includes scar management, psychological support, and addressing residual physical impairments, necessitating a multidisciplinary approach. Research into adjunctive therapies like cyclosporine, intravenous immunoglobulin, and plasmapheresis continues, aiming to refine treatment strategies and enhance patient outcomes.

In conclusion, while this reaction is relatively rare and uncommon, SJS/TEN poses significant clinical challenges due to its rapid onset, potential for severe morbidity and mortality, and long-term impact on survivors. This is a painful and difficult treatment that can greatly impede on the quality of life of a person. Vigilance in medication management, early recognition, and comprehensive supportive care are paramount and absolutely necessary in mitigating the devastating effects of this complex and life-threatening condition.

Kumar, R., Das, A., & Das, S. (2018). Management of Stevens-Johnson Syndrome-Toxic Epidermal Necrolysis: Looking Beyond Guidelines!. Indian journal of dermatology, 63(2), 117–124. https://doi.org/10.4103/ijd.IJD_583_17

Marks, M. E., Botta, R. K., Abe, R., Beachkofsky, T. M., Boothman, I., Carleton, B. C., Chung, W. H., Cibotti, R. R., Dodiuk-Gad, R. P., Grimstein, C., Hasegawa, A., Hoofnagle, J. H., Hung, S. I., Kaffenberger, B., Kroshinsky, D., Lehloenya, R. J., Martin-Pozo, M., Micheletti, R. G., Mockenhaupt, M., Nagao, K., … Phillips, E. J. (2023). Updates in SJS/TEN: collaboration, innovation, and community. Frontiers in medicine, 10, 1213889. https://doi.org/10.3389/fmed.2023.1213889