Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN) Overlap Syndrome

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN) Overlap Syndrome is a serious skin condition that affects the skin and mucous membranes, causing widespread redness, blistering, and peeling. It usually happens as a reaction to certain medications or infections. The condition damages the outer layer of the skin, leading to painful sores and making the body vulnerable to infections and fluid loss. It can also affect the eyes, mouth, and other organs, causing severe discomfort and complications. Because it involves a large area of skin, it requires urgent medical attention to prevent life-threatening problems.

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN) Overlap Syndrome is a severe mucocutaneous reaction characterized by widespread epidermal necrosis and detachment involving 10-30% of the body surface area, representing an intermediate severity between SJS (<10% BSA) and TEN (>30% BSA). It is primarily caused by a type IV hypersensitivity reaction to drugs such as anticonvulsants, sulfonamides, and allopurinol, or less commonly infections. The pathogenesis involves cytotoxic T-cell mediated apoptosis of keratinocytes leading to full-thickness epidermal necrosis. Clinically, it presents with fever, malaise, painful erythematous macules, targetoid lesions, and mucosal erosions. The condition is a dermatologic emergency due to risks of sepsis, fluid loss, and multi-organ failure. Early recognition and differentiation from other blistering disorders are critical for prognosis.