Stevens-Johnson Syndrome

Stevens-Johnson syndrome (SJS) is a rare but serious disorder of the skin and mucous membranes, usually caused by an adverse reaction to medications or infections.

Definition and Classification

SJS is considered a form of toxic epidermal necrolysis (TEN), with the distinction between the two conditions based on the extent of skin detachment. SJS is characterized by less than 10% of the body surface area being affected, whereas TEN involves more than 30%. The condition in between, with 10-30% of the body surface area involved, is sometimes referred to as SJS/TEN overlap.

Causes and Risk Factors

The most common causes of SJS include:

• Medications: Such as antibiotics (e.g., sulfonamides, penicillins), anticonvulsants (e.g., carbamazepine, phenytoin), nonsteroidal anti-inflammatory drugs (NSAIDs), and allopurinol.
• Infections: Including those caused by Mycoplasma pneumoniae, herpes simplex virus, and cytomegalovirus.

Other risk factors may include genetic predisposition and immunological disorders.

Symptoms

The symptoms of SJS can vary but typically include:

• Fever
• Skin lesions or blisters, which can merge to form large areas of damaged skin
• Mucous membrane involvement, leading to symptoms such as conjunctivitis, oral ulcers, and genital ulcers
• Respiratory, gastrointestinal, or urinary tract involvement in severe cases

Diagnosis

Diagnosis of SJS is based on clinical presentation, medical history, and laboratory tests to rule out other conditions. Key diagnostic features include:

• Clinical examination of skin lesions and mucous membranes
• Blood tests for signs of infection or inflammation
• Skin biopsy to confirm the diagnosis and assess the extent of skin involvement

Treatment and Management

The primary goal in treating SJS is to stop the use of any offending medication, manage symptoms, and prevent complications. Treatment strategies may include:

• Withdrawal of the suspected causative agent
• Supportive care: Fluid replacement, wound care, nutritional support, and pain management
• Use of corticosteroids or immunoglobulins in some cases to reduce inflammation and immune response
• Ophthalmological care for eye involvement to prevent long-term vision problems

Prognosis and Complications

The prognosis for SJS varies depending on the severity of the condition, the promptness and effectiveness of treatment, and the presence of complications. Potential complications include:

• Infections of the skin lesions or other body sites
• Respiratory failure
• Sepsis
• Long-term sequelae such as scarring, vision loss, and chronic health issues

Prevention

Preventing SJS involves careful monitoring of patients starting new medications known to be associated with the condition. Early recognition of symptoms is crucial for effective management and reducing the risk of severe outcomes.