Randy Jacobs, M.D. Patient Education

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Erythema Multiforme


Erythema Multiforme




Erythema multiforme is the name given to a short-lasting illness, which sometimes recurs. It causes a rash and often blisters in the mouth and elsewhere. There are three subtypes:


Erythema multiforme "minor"

This results in uncomfortable round skin lesions on the forearms, hands, knees and feet. Some of the skin patches appear like a target, i.e. rings of red and pink. Often the centre of the patch forms a fluid-filled blister. Sometimes, the rash is accompanied by sores and blisters on the lips. The patient may be mildly off color, but recovers in a few days or up to three weeks.


Erythema multiforme "major"

In this less common form, the mouth, eyes and genitals are red, blistered and sore. In such cases, the patient usually feels unwell with a high temperature, and may find it difficult to eat and drink. This is sometimes called Stevens-Johnson syndrome, and may require admission to hospital.


Toxic epidermal necrolysis (TEN)

TEN is serious but luckily rare. The patient is very ill, and the skin over large parts of the body peels off in sheets, like a serious burn. TEN is often a severe allergic reaction to a medicine, which must NEVER be taken again.



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



Dr. Jacobs will probably diagnose erythema multiforme from the appearance of the rash, but sometimes a small skin biopsy is necessary. Blood tests and skin swabs may be arranged. Treatment varies. Dr. Jacobs may prescribe: Steroid creams, steroid tablets, antibiotics, and soothing preparations such as wet compresses. Pain-killing antiseptic mouthwashes can help if the mouth and lips are affected. 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, medicine called acyclovir may prevent it.



Erythema Multiforme Facts



Erythema multiforme is an iflammatory reaction pattern ranging from:

EM minor to EM major to TEN


Physical Exam

Target lesions are not pathognomonic



Immune complexes are deposited in blood vessel walls

Membrane Attack Complexes cause vessel damage



HSV is the most common

Mycoplasma Pneumoniae

Strep and Staph, Histoplasma

Sulfa is the most common drug

Pcn, Dilantin, NSAID, Barbituates

Cancer, pregnancy

50% of EM is idiopathic


Possible Opthalmology & Pulmonary evaluation

Infectious work-up for HSV, staph-strep, mycoplasma, & histoplasma.



EM minor will last 2 to 3 weeks Treat with antihistamines, TCN, Erythromicin, Zovirax, Silvadene for topical care.

EM major will last 6 to 8 weeks.



May need IV fluids.


Systemic steroids: Are used only in certain cases.