Stevens Johnson Syndrome (SJS) is an acute inflammatory reaction that involves skin & muco-cutaneous junction. Stevens Johnson syndrome is a severe hypersensitivity reaction which can occur at any age group. Mortality rate ranges from 5% to 10%. As primary involvement is skin related, patient is presented to dermatologist at first place, after resolution of primary skin lesion; patient is referred to ophthalmologist for management of ocular complication of SJS.

Why do eyes get involved?
Its hypersensitivity reaction involves skin, mucus membrane & muco-cutaneous junction. So ocular involvement is common and its presentation ranges from mild conjunctivitis to severe corneal ulceration & corneal keratinization. Corneal ulceration, vascularization, perforation can lead to blindness in late stages. Early intervention & proper ocular management can prevent such nasty ocular complications.

What causes SJ Syndrome (How does Stevens Johnson syndrome start)?
Certain medications can trigger SJ reaction e.g. lamotrigine, carbamazepine, allopurinol, sulphonamides, nevirapine and many more. 
Certain diseases like cytomegalo virus, herpes, mumps infection, mycoplasma pneumoniae, mycobacterium, brucellosis, typhoid, diphtheria, fungal & parasitic infection etc. can also cause SJS, though exact mechanism is unknown.
Risk factors include HIV / AIDS, SLE (Systemic Lupus Erythematosus) etc.

Stevens Johnson Syndrome symptoms and presentation: 

In SJ Syndrome, Skin involvement is usually less than 10%. If more than 30% skin is involved, same condition is known as TEN (Toxic epidermal necrolysis). Pre-syndrome symptoms are similar to flu symptoms e.g. headache, myalgia, fever, sore throat, cough, burning sensation in eyes. As it mimics mild URTI (Upper Respiratory tract Infection), inadvertent misdiagnosis & antibiotic treatment trigger type 4 hypersensitivity reaction which leads to SJ Syndrome. Ulcers appear over mouth, lips, ano-genital areas which are very painful. Membranous Conjunctivitis is also seen. Typical target lesion like rashes, ulcers appear over face, trunk, arms, legs, sole. Patient usually get admitted to Burn Unit/ICU for stabilization of vitals.

So, in normal scenario, Ophthalmologist get to see SJ syndrome affected patient after acute phase of disease which mostly lasts for 2 to 6 weeks.

Prophylaxis: 
Practically, its almost next to impossible to prevent SJ syndrome as there is no reliable test which links antibiotics & occurrence of SJS in an individual. We are only left with optimal management of episode of SJS.

Stevens Johnson Syndrome Treatment:

Its dermatological emergency which is managed in BURN unit/ ICU. The line of treatment is similar to burn management with proper maintenance of hydration and skin ulcer management. Early steroid has controversial role. IV Immunoglobulin shows some promising results.

Role of Ophthalmologist:
Ophthalmologist should be consulted immediately as soon as patient gets stabilized.

Ocular involvements:
Early: Membranous/ Pseudo membranous conjunctivitis, Corneal ulcer & its complications. 
Late complications: Anomalies of eyelid positions (Ectropion: Outward turning of lids, Entropion: inward turning of lids, symblepharon: sticking of lid conjunctiva to bulbar (ocular surface) conjunctiva etc.), Inward turning of eyelashes(trichiasis), Keratinization/crusting of eyelid margin, dry eyes, scarring of lacrimal duct punctum, keratinization of conjunctiva, corneal vascularization, corneal opacification.

Early intervention is important for prevention of late ocular complication.
In critical acute phase, local treatment plays important role. Measures included artificial lubricants, ointments, copious irrigation of conjunctival sac with preservative free solutions, removal of pseudomembrane, swiping glass rod through conjunctival sac, Symblepharon ring insertion.
Topical antibiotics prevent secondary infection, topical steroids prevent scar formation, topical cycloplegics to relieve pain, photophobia, ciliary spasms. Corneal epithelium is protected with BCL. Since patients do not get meticulous treatment in early stage, they tend to develop late complications. So usually patients come to ophthalmologist after development of late complications.

Surgical management:

Is Stevens Johnson Syndrome curable? This is a question that many have. There are several surgeries which can be done based on the stage and the associated complications. 
1. Amniotic Membrane grafting in acute stages can help reduce the surface inflammation and prevent long term sequalae.
2. Mucosal Membrane grafting especially of the keratinized lid margin can go a long way to reduce future risk of limbal stem cell damage.
3. SLET (Simple limbal epithelium transplantation) is useful in ocular surface reconstruction if limbal stem cell deficiency causes poor vision
4. Correction of lid and Eyelash abnormalities are necessary to maintain corneal epithelial integrity and healthy ocular surface.
5. Corneal transplantation is advised in case of central corneal opacity involving visual axis. This is done only after the other parts of ocular surface like lid and stem cells and conjunctiva are stabilized.