Erythema Multiforme and Stevens-johnson Syndrome

Erythema multiforme (EM) and Stevens-Johnson (SJ) syndrome constitute two ends of a spectrum of the same disease. EM is the mild form; SJ is the more severe, potentially fatal form. In patients who have Stevens-Johnson syndrome, the skin eruption generally involves the mucous membranes. Patients appear clinically ill and may suffer from multisystem dysfunction. EM/SJ is usually the result of a hypersensitivity (allergic) reaction either to a medication or infection (Mycoplasma pneumoniae and herpes simplex most frequently), although a cause is not identified in half of the cases.

Causes

Erythema multiforme is a type of hypersensitivity reaction that occurs in response to medications, infections. Medications associated with erythema multiforme such as including sulfonamides, penicillins, barbiturates, and phenytoin. Associated infections include herpes simplex and mycoplasma infections.

The exact cause is unknown. The disorder is believed to involve damage to the blood vessels of the skin with subsequent damage to skin tissues. Approximately 90% of erythema multiforme cases are associated with herpes simplex. The disorder occurs primarily in children and young adults.

The following infectious diseases have been reported to cause this disorder:

• Adenoviruses
• Calmette-Guérin virus
• Deep fungal infections
• Enterobacter
• Enteroviruses
• HSV
• Influenza
• Measles
• Mumps

Symptoms

• SJ usually begins with a prodrome: upper respiratory tract infection, fever, headache, malaise.
• Rash

Signs

• EM: rash usually begins as erythematous macules and papules, found symmetrically on the hands and feet. The rash spreads and evolves into the classic target-appearing lesions (dark center with a lighter outside ring).
• SJ: erythematous blisters are also seen on the mucous membranes of the eyes, mouth, and genitalia. The lesions may progress to bullae and then slough. The patient's lips may have a characteristic thick hemorrhagic crust.

Treatment

Treatment of mild and severe symptoms may include:

• Moist compresses applied to skin lesions
• Medications such as antihistamines to control itching
• Over-the-counter medications to reduce fever and discomfort
• Topical anesthetics to ease discomfort that interferes with eating and drinking
• Systemic corticosteroids to control inflammation
• Intravenous immunoglobulins to stop the process
• Aggressive monitoring and replacement of fluids and electrolytes are of paramount importance.
• Provide supportive respiratory care, including suctioning and postural drainage, as needed.