SJS/TEN and Eye Disorders

SJS/TEN is a type of severe drug eruption and is a systemic mucocutaneous disease. It causes erosion and blistering on the skin and mucous membranes throughout the body along with a sudden high fever and conjunctivitis. Approximately 60% to 70% of patients have been reported to experience ocular complications in the acute phase, and approximately half of the patients experience serious ocular complications such as keratoconjunctival epithelial defect and pseudomembrane formation. This means that about one third of patients diagnosed as having SJS/TEN experience serious ocular complications in the acute phase and have sequelae such as severe dry eye and visual impairment in the chronic phase. In the worst-case scenario, such ocular complications may result in vision loss.

As the fatality rate is high, the core focus is on whole-body control. But even if the person's life is saved, after-effects such as high visual impairment and dry eye syndrome can occur, and rehabilitation can be extremely difficult. (Please see the figure below).

Stevens-Johnson syndrome (SJS) treated by ophthalmologists includes only SJS and TEN which are diagnosed by dermatologists and are accompanied by serious ocular mucosal disorders. This means that SJS treated by ophthalmologists accounts only for a part of SJS/TEN diagnosed by dermatologists.

Dermatologists diagnose SJS according to the area of epidermal detachment in the acute phase of <10% and diagnose toxic epidermal necrolysis (TEN) according to that of ≥10%. Since skin lesions are no longer noted in the chronic phase, it is impossible to distinguish SJS from TEN on the basis of the findings from patients.

On the other hand, because patients with SJS/TEN who visit an ophthalmologist are often in the chronic phase of the disease, it is difficult to know the degree of epidermal detachment in the acute phase. So, ophthalmologists often diagnose SJS and TEN collectively as broad-sense SJS on the basis of the previous sudden-onset skin eruption and mucosal lesions together with the distinctive ocular manifestations in the chronic phase of SJS/TEN such as serious dry eye, trichiasis and symblepharon observed on physical examination.

Patients with SJS that causes serious ocular sequelae requiring ophthalmologic treatment in the chronic phase account only for a part of patients diagnosed as having SJS or TEN by dermatologists. SJS can never be diagnosed without presence of mucosal lesions while TEN can be diagnosed without it. Besides, not all patients with mucosal lesions experience serious conjunctivitis. According to a collaborative survey conducted by ophthalmologists and dermatologists, patients with serious ocular complications of pseudomembrane formation and keratoconjunctival epithelial defect in the acute phase accounted for approximately 40% of all the patients with SJS/TEN.