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Erythema Multiforme

This reaction pattern of blood vessels in the dermis with secondary epidcrmal changes is exhibited clinically as characteristic erythematous iris-shaped papules and vesicolobullous lesions typically involving the extremities (especially the palms and soles) and till the mucous membranes. Erythema multiforme can be minor or more severe. The more severe form is also known as Stevens-Johnson syndrome. Severe reactions can involve the skin, lungs, kidneys, eyes, and other areas.

EM is relatively common problem for a dermatologist. Half the cases are in young people (under 20). It rare both under the age of 3 and over the age of

Causes of Erythema multiforme

The cause of erythema multiforme often remains unknown. Possible causes include: Viral infection (especially herpes simplex ) Mycoplasma pneumonia (a chest infection) Medicines (especially those containing sulfa) Immunizations

Signs and symptoms of Erythema multiforme

• Multiple skin lesions:
  • With sudden onset, which may recur
  • That may spread
  • Located on the legs, arms, palms, hands, or feet
  • May involve the face or lips
  • Trunk is usually not involved
  • Usually symmetrical
• Itching of the skin may be present
• Fever
• Dry eyes
• General ill feeling

On the skin, a wide variety of irregular red macular, papular and vesicular lesions may occur, either separately or in combination. A unique lesion, the target or bull's-eye lesion appears as concentric rings of affected skin interspersed with rings of clinically normal skin, often with a bullous lesion at the center.

Diagnosis

The diagnosis is primarily based on the appearance of the skin lesion and its typical symmetrical distribution, especially if there is a history of risk factors or associated diseases.

Treatment of Erythema multiforme

Treatment of Erythema multiforme begins with identification and removal of the trigger factor, however that is not always possible. EM minor is typically asymptomatic and therefore needs no treatment, as the lesions will clear up by themselves within 2-4 weeks. In herpes virus induced EM minor, Zovirax or Valtrex pills will help, but only if started in the first few days. If the EM keeps recurring, a continuous low dose of Zovirax or Valtrex will prevent it.

Corticosteroids In severely ill patients temic corticosteroids are usually given (prednisone 50 to 80 mg/d in divided doses, quickly tapered), but their effectiveness has not beeen established by controlled studies.

Most cases of erythema multiforme completely recover. There may be dark marks for a few months when the patches clear up. Sometimes, the condition recurs, particularly if the cold sore virus was the cause. If it happens several times a year, continuous aciclovir may prevent it.

Prevention of Erythema multiforme

• Good hygiene and isolation from others may be required to prevent secondary infections .
• Control of herpes simplex oral acyclovir may prevent development current erythema multiforme.