Erythema
multiforme is a rare immune mediated allergic inflammatory skin
disorder of unknown origin which can occur in response to medications,
infections, or illness. These may include viral and bacterial
infection, chronic disease of the visceral organs, cancer or other
diseases and/or hypersensitivity reactions to drugs. The disorder
is believed to involve damage to the blood vessels of the skin with
subsequent damage to skin tissues. Erythema multiforme can
be minor or more severe. The minor form is an acute, self limiting
disease that affects the skin but mucous membranes little, if at all.
The major form has more involvement of both skin and mucosa and is a
potentially life threatening condition. The more severe form is
also known as Stevens-Johnson syndrome. Severe reactions can
involve the skin, lungs, kidneys, eyes, and other areas.
Symptoms Acute eruption
of skin and mucous membranes characterized by bull's-eye 'type raised
blisters, with red rims and blanching at center. The reddened
areas usually are symptomless, although they sometimes itch
mildly. Painful blisters often form on the lips and lining of the
mouth but not the eyes. These lesions are usually distributed
symetrically over the body. They are most often seen around mouth,
eyelids,ears, groin, armpits and anus; in some instances, ulcers
develop. Depression,
fever and hair loss may also be present.
Diagnosis Diagnosis is
based on history, clinical signs and laboratory findings which rule out
other diseases causing similar signs and skin biopsy The condition is
usually difficult to differentiate from lupus erythematosus and
ulcerative dermatosis. The most common underlying causes are infections
(e.g., staphylococcal folliculitis, and anal gland sacculitis,
bacterial endocarditis), drugs (e.g., chloramphenicol, cephalexin,
diethylcarbamazine, trimethoprim-sulfonamides, etc.), and cancers
(e.g., bone disorders, splenic tumors). According to recent changes in
the disease classification and identification, erythema multiforme is
suspected if patchy lesions with ulcerations are present on less than
10% of the body surface and with more than one mucous membranes
affected.
Treatment The
primary goal of treatment is to supress the body's immune response with
large doses of systemic glucortoids. Prevention
of erythema multiforme is only possible when the cause is known.
If it is caused by a medication, the medication may need to be
stopped. Anti-inflammatory
doses of prednisolone (0.5 to 1.0 mg/kg/day) may be given to decrease
the inflammation and itch when present but are controversial because
they can also aggravate some cases. Pentoxifylline has been used
occasionally, at 5 to 10 mg/kg 3 times a day, with variable results in
recurrent, non-drug associated cases. azathioprine, sulfasalazine and
cyclosporine have also been used as treatments in resistant cases.
