Stevens-Johnson syndrome

Also called SJS, Toxic epidermal necrolysis, TEN

A rare, severe reaction in which the skin blisters and peels. Almost always caused by a medicine, and stopping it early is what saves people.

What it is

A severe reaction, usually to a medicine, in which the skin and the linings of the mouth, eyes and genitals blister and detach. Toxic epidermal necrolysis is the same process affecting more of the body surface, and it is treated in burns units.

It is rare and it is a genuine emergency. Mortality is significant, and the strongest predictor of survival is how quickly the causative drug is stopped.

The drugs most often responsible are recognisable and widely used: allopurinol, some antibiotics including sulfonamides, anti-epileptic drugs such as carbamazepine, lamotrigine and phenytoin, nevirapine, and anti-inflammatory painkillers. Reactions usually begin one to four weeks after starting the drug.

It begins deceptively, with fever and flu-like symptoms and a sore mouth or eyes for a day or two before any rash. A painful rash with mouth and eye involvement in somebody who recently started a new medicine is the pattern.

Genetic risk is testable for some drugs in some populations, notably HLA-B*1502 and carbamazepine in people of South East Asian ancestry.

Survivors are frequently left with lasting eye problems, and eye involvement must be assessed by an ophthalmologist from the first day.

Signs you might notice

Fever, sore throat, aching, and feeling generally unwell, one to four weeks after a new medicine.

Painful, burning eyes, and a sore mouth or throat before any rash.

A rash of red or purple patches, sometimes with a target appearance, spreading and becoming painful.

Blisters, and skin peeling away in sheets. Skin that shears off when gently rubbed.

Sores and ulcers in the mouth, eyes, nose and genitals.

999 or A and E immediately, and stop the suspected medicine. Say the words Stevens-Johnson syndrome; it changes where the person is sent.

Any painful rash with mouth or eye involvement after a new drug is this until proven otherwise.

How it can affect day-to-day life

Recovery is long. Skin heals over weeks, but eye complications, dry eyes, scarring and sight loss can be permanent, and lifelong ophthalmology follow-up is often needed.

Lasting effects also include scarring, altered pigmentation, nail loss, dry mouth and genital scarring, and significant psychological trauma. Support for that is rarely offered.

The causative drug and its whole chemical class must be avoided for life, and that has to be recorded everywhere: GP record, hospital record, pharmacy, and a medical alert card or bracelet.

Families need telling too, because some of the genetic risk factors are inherited.

Supporting someone well

Learn the one-to-four-week window after any new medicine, particularly the drugs named above, and treat a painful rash with mouth or eye symptoms as an emergency.

Stop the suspected drug immediately and take the packet or a list to hospital.

Go to A and E rather than a GP, and say the name of the syndrome.

Ask for ophthalmology assessment on day one, not when the skin has settled.

Make sure the drug and its class are recorded as an allergy on every record, and get an alert card or bracelet.

Ask about genetic testing where relevant, and tell close relatives.

Ask for psychological support afterwards; the experience is traumatic and the appearance changes are real.

Where to get help

999 or A and E immediately. Severe cases are treated in burns or specialist dermatology units.

Ophthalmology from the outset and for long-term follow-up.

A GP practice afterwards to ensure the allergy is recorded across all systems.

British Association of Dermatologists publish patient information on severe drug reactions.