Erythema multiforme

Alternative names

Lyell's syndrome; Stevens-Johnson syndrome; Toxic epidermal necrolysis

Definition

Erythema multiforme is a skin disorder resulting from an allergic reaction.

Causes, incidence, and risk factors

Erythema multiforme is a type of hypersensitivity (allergic) reaction that occurs in response to medications, infections, or illness. Medications associated with erythema multiforme include 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 or mycoplasma infections. The disorder occurs primarily in children and young adults.

Erythema multiforme may become noticeable with a classic skin lesion, with or without systemic (whole body) symptoms. In Stevens-Johnson syndrome, the systemic symptoms are severe and the lesions are extensive, involving multiple body areas, especially the mucous membranes. Toxic epidermal necrolysis (TEN syndrome, or Lyell's syndrome) involves multiple large blisters (bullae) that coalesce, followed by sloughing of all or most of the skin and mucous membranes.

Symptoms

• Multiple skin lesions:
  o With sudden onset, which may recur
  o That may spread
  o That may appear as nodule, papule, or macule
  o Central lesion surrounded by concentric rings of paleness and redness, also called "target", "iris", or "bull's eye"
  o May have vesicles and bullae (blisters of various sizes)
  o Located on the legs, arms, palms, hands, or feet
  o May involve the face or lips
  o Trunk is usually not involved
  o Usually symmetrical
  
• Itching of the skin may be present
  
• Fever
  
• General ill feeling
  
• Joint aches
  

Additional symptoms that may be associated with this disease:

• Vision abnormalities
  
• Dry eyes
  
• Bloodshot eyes
  
• Eye pain
  
• Eye burning, itching and discharge
  
• Mouth sores
  

Signs and tests