Stevens-Johnson Syndrome (SJS) is a rare yet life-threatening dermatological emergency marked by acute, extensive destruction of mucocutaneous tissues.
Primarily triggered by reactions to specific medications or, less commonly, infections, SJS rapidly progresses, leading to significant morbidity and risk of fatal complications if not swiftly recognized and managed.
Pathogenesis: Immunological Storm Behind SJS
The hallmark of SJS is a massive, dysregulated immune reaction—primarily involving cytotoxic T lymphocytes and natural killer cells—which leads to widespread apoptosis of keratinocytes.
This results from drug or microbial antigens binding to major histocompatibility complex molecules, triggering the release of cytotoxic mediators, such as granulysin and perforin, which account for the severe tissue injury seen in SJS and its more extensive form, toxic epidermal necrolysis (TEN).
Triggering Agents and Risk Identification
Medications are the most frequent culprit, especially anticonvulsants (carbamazepine, phenytoin, lamotrigine), sulfonamide antibiotics, allopurinol, and certain antiretrovirals. Acute onset typically occurs within the first two months after exposure. Viral pathogens, such as Mycoplasma pneumoniae, represent less common but important triggers, particularly in children.
Clinical Presentation: Early Clues and Progression
SJS usually begins with non-specific prodromal symptoms—high fever, malaise, and sore throat before the appearance of painful, rapidly coalescing red or purple macules and blisters. Lesions frequently involve mucous membranes, including the mouth, eyes, and genitalia, leading to erosions, conjunctivitis, and severe pain.
Diagnostic Advancements and Assessment
Definitive diagnosis of SJS relies on clinical assessment, sometimes supported by a skin biopsy revealing full-thickness epidermal necrosis with minimal dermal inflammation. The extent of skin involvement distinguishes SJS (<10% body surface area detachment) from TEN (>30%), with overlap in intermediate cases.
Management: Multidisciplinary and Time-Sensitive Interventions
Immediate cessation of the suspected offending drug is the cornerstone of effective management. Supportive care in an intensive or burn unit setting addresses fluid and electrolyte imbalances, temperature regulation, infection prophylaxis, and nutritional needs.
Immunomodulatory therapies such as intravenous immunoglobulin (IVIG) and cyclosporine are subjects of ongoing investigation, with some studies suggesting improved outcomes when initiated early, though consensus on their routine application is evolving.
Complications and Prognosis
Severe complications abound, including sepsis, multi-organ dysfunction, profound mucosal scarring, and chronic ocular sequelae like blindness due to severe conjunctival involvement. Mortality rates fluctuate between 10% and 30%, closely related to the degree of skin loss and systemic compromise, as assessed with validated scoring systems (e.g., SCORTEN).
Dr. Ron Feldman, a leading expert in cutaneous drug reactions, emphasizes "Stevens-Johnson syndrome is a dire medical emergency. The rapid identification and discontinuation of the causative agent can mean the difference between survival and life-threatening complications."
Similarly, Dr. Robert Micheletti, a prominent dermatologist specialized in severe skin diseases, states "A multidisciplinary approach, including dermatology, critical care, and ophthalmology, is crucial to optimize survival and minimize long-term complications for patients with SJS/TEN."
Stevens-Johnson Syndrome exemplifies a rapidly evolving skin emergency characterized by massive keratinocyte death and extensive mucosal involvement, most commonly triggered by specific medications. As underscored by expert commentary, vigilance, and prompt, coordinated intervention are critical to addressing this severe cutaneous adverse reaction.
