Stevens Johnson syndrome is a very severe condition that attacks the immune system and causes the death of cells. It is thought to be a hypersensitivity complex, and generally affects the skin and mucus membranes of the human body. It can range in severity, sometimes being a fatal disorder (the mortality rate is 1-3%). Less severe cases result in milder skin lesions. Patients usually make a full recovery, with problems only occurring if there are underlying complications. Complications can include necrosis, renal failure, skin infection and in the long term there may be scarring of tissue.
It is a fairly rare disease, occurring in approximately 2-3 people per million in Europe, generally in the winter and early spring seasons. Patients tend to be in the age range 10-30, although this is not concrete and rare cases have been seen in younger children. More cases have been seen in women than men, and Caucasians tend to be more susceptible than other ethnic groups.
Stevens Johnson syndrome usually begins with fever and fatigue – if misdiagnosed it will progress causing lesions that are often found in the mouth area first. Patients usually have a past history of Stevens-Johnson or erythema multiforme – a skin disorder that comes as a result of an allergic reaction or infection. Symptoms may be manifested in the eye region, and Johnson syndrome has been known to cause blindness in patients. Patients may lose consciousness and exhibit signs of tachycardia. Other diagnoses include things such as chemical or thermal burns and Lyme disease.
Toxic epidermal necrosis is related to Stevens Johnson syndrome, but has a higher mortality rate of 30-35%. The difference between them is mainly the severity of the skin lesions.
Causes include drugs and infections, although in children the main cause of Stevens-Johnson is infection. Infections causing this disease can include viral infections such as herpes simplex, mumps, hepatitis, HIV and Epstein-Barr. As far as bacterial infections go, diphtheria, typhoid and streptococcus can all progress on to Stevens-Johnson syndrome. Fungal and protozoal causes include dermatophytosis and malaria respectively. This is by no means an exhaustive list.
The syndrome has also been associated with immunization for things such as hepatitis B and measles, and certain drugs have been implicated – penicillin and some anti-inflammatories. Radiation therapy as a cancer treatment has been known to cause Johnson syndrome, as has the use of drugs such as cocaine. Having said all of this, in 25-30% of cases, the syndrome is idiopathic – that is, there is no underlying cause for its presentation.
Once it has presented itself, lesions may continue for up to 2-3 weeks. They are not generally itchy, but if presenting in the mouth may mean that patients cannot eat or drink due to the severity of pain they are experiencing.
Patients may need intravenous fluids, especially if they have lesions in their mouth area. Effective pain control measures should also be put in place in order to make the patient more comfortable. Skin lesions are treated in the same way that burns are treated, but for the mouth area, things such as mouthwashes and topical anaesthetics are helpful in easing the pain of the patient. An early diagnosis and treatment of intravenous immunoglobulin helps to reduce the mortality rate and cure Stevens Johnson syndrome quickly.