Toxic epidermal necrolysis: signs and treatment

The British Association of Dermatologists describes SJS/TEN as a rare, severe skin reaction with a blistering rash plus inflammation of the eyes, mouth, nose and genitals. The top layer of skin, the epidermis, can detach and leave the lower layer, the dermis, exposed.

SJS and TEN are two names for the milder and the severe forms of the same condition. The association gives blistering of less than 10% of body surface area for SJS and more than 30% for TEN. The terms are often used together as SJS/TEN.

It is a medical emergency. This page is for information, and anyone who thinks they have these signs should get urgent help.

The NHS says it can start with flu-like symptoms such as a high temperature, sore throat, cough and joint pain. A rash appears a few days later, usually starting on the upper body and quickly spreading to the face, arms, legs and other areas including the genitals. It may be itchy or painful, and often consists of circular patches that are darker in the middle and lighter outside.

Blisters then appear and burst, leaving painful sores, and the skin often peels very easily. The NHS says blisters and sores can also appear on the lips and in the mouth and throat, making swallowing painful, in the urethra, causing pain passing urine, and on the eyes, causing eye pain, pain in bright light and problems with sight. Diarrhoea, vomiting and wheezing may also occur.

The British Association of Dermatologists says a painful red or purple rash appears, and its leaflet for young people adds that the colour of the rash varies depending on the colour of your skin.

The NHS says it is often caused by the body reacting to certain medicines, particularly some epilepsy medicines, antibiotics and anti-inflammatory painkillers. It lists allopurinol, carbamazepine, lamotrigine, nevirapine, oxicam anti-inflammatories such as meloxicam and piroxicam, phenobarbital, phenytoin, sulfamethoxazole and other sulfa antibiotics, and sulfasalazine as commonly linked. In children, infections such as colds, cold sores and glandular fever can be causes.

The British Association of Dermatologists says almost any medicine can cause it, including over-the-counter and herbal preparations, and that sometimes no trigger is found. It adds that it is not clear why some people react so intensely, and that there can be a genetic predisposition in certain ethnic populations.

The NHS says the risk is low even when taking a medicine known to cause it. You are more likely to get it if you have had it before after a certain medicine, or have a weakened immune system.

The British Association of Dermatologists says there are no specific blood tests. A definitive diagnosis comes from the doctors' assessment of the skin, usually along with a skin biopsy, taking a very small sample of skin to examine under a microscope.

For children, its leaflet says doctors also run tests to understand the cause, including blood tests, a swab inside the mouth, skin swabs and sometimes a skin sample. If a medicine is suspected, some people have further tests after recovery to confirm the reaction.

The NHS says it is treated in hospital, sometimes in intensive care. If a medicine is thought to be the cause, it is stopped. Treatment relieves symptoms and may include fluids into a vein, specialised wound care, creams and dressings, strong painkillers, and medicines to control inflammation and prevent infection. Very severe cases may need surgery.

The British Association of Dermatologists says early treatment matters, and that if skin loss is extensive, care may be on an intensive care or burns unit. The aims are to minimise further skin loss, prevent infection, provide hydration and nutrition and relieve pain. It says there is no clear evidence for any treatment with tablets or injections, and that stopping the culprit drug plus high-quality supportive care remains the priority.

Care involves many specialties, which may include dermatology, ophthalmology, intensive care, burns, plastic surgery, respiratory and renal medicine, with dietitians and physiotherapists. Eye drops and ointments are used to protect the eyes.

The NHS says it may take several weeks or months to recover fully. Skin usually takes about 2 or 3 weeks to heal, but sometimes longer if a skin infection develops. You are likely to feel very tired for a few weeks after leaving hospital.

The NHS lists possible complications including skin infection, colour change and scarring, problems with the lungs, liver and kidneys, long-term eye inflammation or sight problems, and scarring of the vagina or penis. The British Association of Dermatologists says the skin stays sensitive to sunlight for many months, so cover up, use sun block of at least SPF 30 and wear sunglasses. Low mood is normal after serious illness, and support is available.

If a medicine caused it, the NHS says you will need to avoid it, and possibly similar ones, for life. Keep a record and consider a medical alert bracelet, as the British Association of Dermatologists advises.

Call 999 or go to A&E if you or your child have a rash spreading across the body after an infection or a new medicine, a rash with itchy or painful, red, swollen, blistered or peeling skin, wheezing, tightness in the chest or throat, trouble breathing or talking, or a swollen or sore mouth, face, lips, tongue, throat or eyes. This is the NHS advice. Do not drive yourself, and take your medicines with you.

TEN is rare, and the NHS says it is treated in hospital, sometimes in intensive care. Choosing between NHS and private care is not usually a decision for the acute phase, because the emergency route is the same. Afterwards, ask which clinic coordinates follow-up with dermatology and eye specialists.