Definition
A.This dermal and epidermal inflammatory process is characterized by symmetric eruption of erythematous, iris-shaped papules (target
lesions), and vesiculobullous lesions.
Incidence
A.Erythema multiforme accounts for up to 1% of dermatology outpatient visits.
B.Adults older than 50 are rarely affected.
C.It may occur in seasonal epidemics.
D.Approximately 90% of cases of erythema multiforme minor follow a recent outbreak of herpes simplex virus (HSV)-1 or mycoplasma infection.
Pathogenesis
A.The disorder is thought to be an immunologic reaction in the skin, possibly triggered by circulating immune complexes.
Predisposing Factors
A.Infections: Recurrent HSV, mycoplasmal infections, and adenoviral infections.
B.Drugs: Sulfonamides, phenytoin, barbiturates, phenylbutazone, penicillin, nonsteroidal anti-inflammatory drugs (NSAIDs).
C.Idiopathic: Greater than 50%; consider occult malignancy.
Common Complaints
A.Rash with intense pruritus.
B.Nonspecific upper respiratory infection followed by rash.
C.General malaise, body aches, joint pain.
D.Fever.
Other Signs and Symptoms
A.Primary: Macules, papules, plaques.
B.Secondary: Erythema, dull red target-like lesions blanch to pressure; distribution is symmetric, primarily on flexor surfaces. Classic target lesions develop abruptly and symmetrically and are heaviest peripherally; they often involve palms and soles.
C.Swelling of hands and feet.
D.Painful oral lesions.
E.Eye discomfort (redness, itching, burning, pain, visual changes).
Subjective Data
A.Ask if the patient has ever been diagnosed with erythema multiforme.
B.Determine whether the onset of symptoms was sudden or gradual.
C.Assess for any associated discharge (blood or pus).
D.Identify the location of the symptoms.
E.Complete a drug history. Has the patient recently taken any antibiotics or other drugs? Question the patient regarding use of any topical medications.
F.Determine the presence of any preceding systemic symptoms (fever, sore throat, anorexia, vaginal discharge).
G.Rule out any possible exposure to industrial or domestic toxins.
H.Question the patient concerning any possible contact with venereal disease.
I.Ask the patient about any close physical contact with others with skin disorders.
J.Elicit information concerning any possible exposure to HIV.
K.Rule out sources of chronic infection, neoplasia, or connective tissue disease.
Physical Examination
A.Check temperature, pulse, respirations, and blood pressure.
B.Inspect:
1.Inspect skin for lesions.
2.Inspect mouth and mucous membranes for lesions.
C.Palpate: Palpate abdomen for masses and tenderness.
D.Auscultate: Auscultate heart, lungs, and abdomen.
E.Neurologic exam.
Diagnostic Tests
A.Punch biopsy of skin.
B.Complete blood count (CBC).
C.Urinalysis.
Differential Diagnoses
A.Erythema multiforme:
1.Erythema multiforme minor: Pruritus, swelling of hands and feet, painful oral lesions.
2.Erythema multiforme major: Fever, arthralgias, myalgias, cough, oral erosions with severe pain.
B.Urticaria.
C.Viral exanthems.
D.Stevens–Johnson syndrome: Stevens–Johnson syndrome (SJS) is a severe, life-threatening, systemic reaction with fever, malaise, cough, sore throat, chest pain, vomiting, diarrhea, myalgia, arthralgia, and severe skin manifestations with painful bullous lesions on mucous membranes.
E.Pemphigus vulgaris.
F.Bullous pemphigoid.
G.Other bullous diseases.
H.Staphylococcal scalded skin syndrome.
Plan
A.General interventions:
1.Identify and treat precipitating causes or triggers.
2.Burow’s solution or warm compresses may be used for mild cases as needed.
3.Oral lesions may be treated with saline solution, warm salt water, and/or Mary’s mouth wash (Benadryl, lidocaine, and Kaopectate).
4.Discontinue any medications suspected of precipitating symptoms.
5.Provide adequate pain relief if skin or oral lesions are painful. Lesions remain fixed at least 7 days.
6.Maintain nutrition and fluid replacement for this hypercatabolic state.
7.Consider chronic viral suppression therapy for recurrent HSV infections.
B.See Section III: Patient Teaching Guide Erythema Multiforme.
C.Pharmaceutical therapy:
1.Antihistamines such as Benadryl or Claritin may be used for itching.
2.Acetaminophen may be used to reduce fever and for general discomfort/pain.
3.Potent topical corticosteroids: Betamethasone dipropionate 0.05% or clobetasol propionate 0.05% twice daily for up to 2 weeks. Avoid use on face and groin.
4.Open lesions should be treated like open burn wounds. Stop offending medications that may cause blistering of wounds and treat with steroids.
5.Oral antibiotics may be needed to control secondary bacterial skin infection.
6.Systemic corticosteroids: Prednisone 40 to 60 mg daily in divided doses, tapered over 2 to 3 weeks.
7.Hospitalization for severe cases. Intravenous (IV) immunoglobulins may be needed.
Follow-Up
A.See the patient in office in 1 to 2 days to evaluate initial treatment.
Consultation/Referral
A.If patient has recurrent or chronic infection, refer him or her to a physician.
B.Immediate consultation and/or hospital admission is critical if SJS is suspected.
C.Patients with ocular involvement should be referred immediately to an ophthalmologist.
Individual Considerations
Geriatrics:
A.Avoid first-generation anticholinergics because of risk of confusion, dry mouth, constipation, and other anticholinergic effects or toxicity.
B.Geriatrics taking alendronate (Fosamax) for osteoporosis therapy have an increased risk of an adverse effect that presents as mucosa erythema multiforme. Recommendations for geriatrics taking this medication is to evaluate any hypersalivation history, swollen lips (macrocheilia), and mouth ulcers that have ill-defined borders and serofibrinous exudates. Treatment measures are local cleaning, cold compresses, and clinical follow-up. Discontinue Fosamax and consider alternative treatment for osteoporosis.