Stevens-Johnson syndrome (erythema multiforme) is an acute inflammatory polymorphic disease affecting skin and mucous membranes. All ages may be affected, and the incidence is equal in both sexes. This is a severe disease with a 5%–15% mortality rate. Ocular involvement, which occurs in as many as half of patients, varies from a mild mucopurulent conjunctivitis to severe perforating corneal ulcers. Blindness occasionally occurs in patients with severe late-phase corneal complications, such as ulceration, vascularization, and perforation.
Stevens-Johnson syndrome has been associated with various bacterial, viral, mycotic, and protozoal infections. Vaccines, collagen diseases, and many drugs have also been implicated. The pathogenesis consists of angiitis leading to erythematous lesions that become edematous or bullous and darken, leaving concentric rings in a target shape. When bullae are present, they are subepidermal and without acantholysis.
Clinical manifestations range from mild to severe. A prodrome of chills is followed by pharyngitis, headache, tachypnea, and tachycardia. In several days, bullous mucosal lesions develop, especially in the oropharynx. These lesions rupture and ulcerate and become covered by gray-white membranes and a hemorrhagic crust.
Ocular involvement in Stevens-Johnson syndrome begins with edema, erythema, and crusting of the eyelids. The palpebral conjunctiva becomes hyperemic, and distinct vesicles or bullae may occur. In many instances, a concomitant conjunctivitis appears that is characterized by watery discharge with mucoid strands (Fig 16-13). Secondary infection, most commonly with Staphylococcus species, may develop. In severe cases, a membranous or pseudomembranous conjunctivitis may result from coalescence of fibrin and necrotic cellular debris. Symblepharon formation may occur with severe pseudomembranous conjunctivitis. Primary corneal involvement and iritis are rare ocular manifestations of Stevens-Johnson syndrome.
Late ocular complications occur in approximately 20% of patients and include structural anomalies of eyelid position (ectropion and entropion), trichiasis, and symblepharon. Dry eye syndrome may also result from deficiencies in the tear film—either in the aqueous layer, from scarring of lacrimal duct orifices, or, more commonly, in the mucin layer, from destruction of the conjunctival goblet cells.
Early intervention is important in preventing the late ocular complications of Stevens-Johnson syndrome. Systemic therapy with corticosteroids is controversial. Antiviral treatment for cases associated with herpes simplex infection may be required. A discussion of systemic treatment is beyond the scope of this book. A dermatologist and pediatric infectious disease expert should be consulted.
Local measures should be instituted early in the course of the disease. Ocular lubrication with artificial tears and ointments (preferably preservative-free) should be applied regularly. Under topical anesthesia, the superior and inferior fornices should be inspected and debrided daily. A glass rod can be used for symblepharon lysis, although this may be ineffective. A symblepharon ring can be useful in severe cases in cooperative patients. Surveillance cultures for microbial infection should be taken as needed. Amniotic membrane grafting may be considered in patients with advanced disease. See also BCSC Section 8, External Disease and Cornea.