Page 99 - Journal of Special Operations Medicine - Fall 2014

and toxic epidermal necrolysis. Today, EM is believed toxic epidermal necrolysis, viral exanthems, paraneo-
to be a separate disorder with distinctive skin lesions. 1,2,3 plastic pemphigus, and Rowell syndrome. Biopsy with
1–4
direct immunofluorescence may be necessary to confirm
Infections account for approximately 90% of cases with the diagnosis. Nonspecific lab abnormalities including
1–4
known etiology. The herpes simplex virus (HSV) and elevated erythrocyte sedimentation rate, leukocytosis,
3
Mycoplasma pneumoniae are the most commonly impli- and elevated liver enzymes are seen in severe cases. 1,3
cated infectious agents. Medications, including sulfon-
1–4
amides, phenytoin, barbiturates, penicillin, allopurinol,
and nonsteroidal anti-inflammatory drugs, account for Treatment
less than 10% of cases. Other identified causes in- Mild cases of EM do not require treatment. In these
1,2
2–4
clude malignancies, menstruation, inflammatory bowel cases, topical steroids and oral antihistamines can be of-
disease, and vaccines (diphtheria-tetanus, hepatitis B, fered for symptomatic relief. Prednisone (40−80mg/
2,3
and smallpox). In about half of all cases, no cause is day, divided) may be necessary for severe cases. If
1–3
1–4
identified. It has been suggested that these may repre- ocular lesions are present, ophthalmology should be
1,4
sent subclinical HSV or Mycoplasma infections. 3,4 consulted. Recurrent cases should receive a 6-month
3
course of acyclovir, valacyclovir, or famciclovir even in
the absence of HSV infection. It should be noted that
1–4
Clinical Course
these medications will not prevent EM if taken after the
The clinical course varies among patients, and lesions onset of HSV lesions. Recurrent cases that cannot be
1
frequently evolve during the course of the disease, hence controlled with HSV prophylaxis should be referred
the term “multiforme.” Severe cases may be preceded to dermatology for further treatment options, includ-
1,3
by a prodrome of constitutional symptoms prior to the ing dapsone, azathioprine, mycophenolate mofetil, im-
onset of dermatological findings. 1,3,4 The lesions tend munoglobulins, hydroxychloroquine, thalidomide, and
to start off as macules distributed symmetrically on the cyclosporine.
1–3
dorsal hands, palms, soles, extensor forearms, face, el-
bows, knees, penis, and vulva. Pain and/or pruritis
1–4
may be present. 1,2,4 After 24 to 48 hours, the macule Disclaimers
may progress into the iris or targetoid lesion. Targetoid The views expressed in this article are those of the au-
1
lesions are described as having three distinct zones: (1) thor and do not necessarily reflect the official policy or
a central area of dusky necrosis or vesicle, (2) a middle position of the Department of the Navy, the Department
zone of edema, and (3) an outer ring of erythema. The of Defense, or the United States Government.
1–3
mucous membranes (lips, oropharynx, nasopharynx,
conjunctiva, vulva, and anus) are involved in 25% to
70% of cases. 1,3,4 The term erythema multiforme ma- Disclosures
jor is used to describe disease involving one or more of The authors have nothing to disclose.
the mucous membranes. The term erythema multi-
3,4
forme minor is used when the mucous membranes are
unaffected. 3,4 References
1. Habif TP. Clinical dermatology, a color guide to diagno-
Most cases of EM are self-limited and resolve about 1 sis and therapy. 5th ed. Maryland Heights, MO: Mosby;
month after onset. 1,2,3 Lesions heal without scarring, 2010.
but postinflammatory hyperpigmentation or hypopig- 2. Lamoreux M, Sternbach M, Hus W. Erythema multiforme.
Am Fam Physician. 2006;74:1883−1888.
mentation may persist for months. Common causes 3. Sokumbi O, Wetter D. Clinical features, diagnosis, and
1,3
of morbidity include keratitis, uveitis, conjunctival scar- treatment of erythema multiforme: a review for the practic-
ring, permanent visual impairment, and esophagitis. ing dermatologist. Int J Dermatol. 2012;51:889−902.
3,4
Recurrence is possible, and rare cases of persistent EM 4. Fitzpatrick T, Wolff K, Johnson R. Color atlas & synopsis
have been described. 3 of clinical dermatology. 6th ed. New York, NY: McGraw-
Hill; 2009.
In cases with targetoid lesions (especially if preceded by
or occurring with HSV infection), the diagnosis is made
clinically. Atypical lesions may resemble a variety of
2,4
dermatologic disorders including drug eruptions, psoria- LCDR Sola is a 2008 graduate of the Uniformed Services Uni-
sis, secondary syphilis, urticaria, Sweet syndrome, acute versity of the Health Sciences. He completed a transitional in-
lupus erythematosus, bullous pemphigoid, dermatitis ternship at Naval Medical Center San Diego in 2009. In 2010,
herpetiformis, leukocytoclastic vasculitis, pityriasis rosea, he completed his training and certification as an undersea and
polymorphic light eruption, Stevens−Johnson syndrome, diving medical officer. He then served for 2 years at the Naval

Erythema Multiforme 91