Erythema multiforme
| Erythema multiforme | |
|---|---|
| Specialty | Dermatology  |
Erythema multiforme is a skin condition of unknown cause, possibly mediated by deposition of immune complex (mostly IgM) in the superficial microvasculature of the skin and oral mucous membrane that usually follows an infection or drug exposure. It is a common disorder, with peak incidence in the second and third decades of life.
Presentation
The condition varies from a mild, self-limited rash (E. multiforme minor)[1] to a severe, life-threatening form known as erythema multiforme major (or erythema multiforme majus) that also involves mucous membranes.
Consensus classification:
- Erythema multiforme minor - Typical targets or raised, edematous papules distributed acrally
- Erythema multiforme major - Typical targets or raised, edematous papules distributed acrally with involvement of one or more mucous membranes; epidermal detachment involves less than 10% of total body surface area (TBSA)
- SJS/TEN - Widespread blisters predominant on the trunk and face, presenting with erythematous or pruritic macules and one or more mucous membrane erosions; epidermal detachment is less than 10% TBSA for Steven-Johnson syndrome and 30% or more for toxic epidermal necrolysis.
The mild form usually presents with mildly itchy (but itching can be very severe), pink-red blotches, symmetrically arranged and starting on the extremities. It often takes on the classical "target lesion" appearance,[3] with a pink-red ring around a pale center. Resolution within 7–10 days is the norm.
Individuals with persistent (chronic) erythema multiforme will often have a lesion form at an injury site, e.g. a minor scratch or abrasion, within a week. Irritation or even pressure from clothing will cause the erythema sore to continue to expand along its margins for weeks or months, long after the original sore at the center heals.
Causes
Many suspected aetiologic factors have been reported to cause EM.[4]
- Infections: Bacterial (including Bacillus Calmette-Guérin (BCG) vaccination, haemolytic Streptococci, legionellosis, leprosy, Neisseria meningitidis, Mycobacterium, Pneumococcus, Salmonella species, Staphylococcus species, Mycoplasma pneumoniae), Chlamydial.
- Fungal
- Parasitic (Trichomonas species, Toxoplasma gondii),
- Viral (especially Herpes simplex)
- Drug reactions, most commonly to: Antibiotics (including, sulphonamides, penicillin), anticonvulsants (phenytoin, barbiturates), aspirin, antituberculoids, and allopurinol and many others.
- Physical factors - Radiotherapy, cold, sunlight
- Others - Collagen diseases, vasculitides, non-Hodgkin lymphoma, leukaemia, multiple myeloma, myeloid metaplasia, polycythemia
EM minor is regarded as being triggered by HSV in almost all cases.[5] A herpetic aetiology also accounts for 55% of cases of EM major.[6] Among the other infections, Mycoplasma infection appears to be a common cause.
Herpes simplex virus suppression and even prophylaxis (with acyclovir) has been shown to prevent recurrent erythema multiforme eruption.[7] The human form of orf can also cause erythema multiforme.[citation needed]
Treatment
Erythema multiforme is frequently self-limiting and requires no treatment. The appropriateness of glucocorticoid therapy can be uncertain, because it is difficult to determine if the course will be a resolving one.[8]
-
Erythema multiforme reaction to an antibiotic -
"Erythema multiforme major" (Stevens–Johnson syndrome); which resembles "erythema multiforme" -
Target lesion -
Erythema Multiforme target lesions on the leg
See also
- Erythema multiforme major
- Erythema multiforme minor
- Toxic epidermal necrolysis
- Stevens–Johnson syndrome
References
- ^ "erythema multiforme" at Dorland's Medical Dictionary
- ^ http://emedicine.medscape.com/article/1122915-overview
- ^ Lamoreux MR, Sternbach MR, Hsu WT (December 2006). "Erythema multiforme". Am Fam Physician. 74 (11): 1883–8. PMID 17168345.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ "Erythema Multiforme on Pubmed Health". Retrieved 28 November 2012.
- ^ Lamoreux MR, Sternbach MR, Hsu WT: Erythema multiforme. Am Fam Physician 2006;74(11):1883-1888.
- ^ Lamoreux MR, Sternbach MR, Hsu WT: Erythema multiforme. Am Fam Physician 2006;74(11):1883-1888.
- ^ Tatnall FM et al: A double blind plaebo controlled trial of continuous acyclovir therapy in recurrent erythema multiforme. Br J Dermatol132:267,1995
- ^ Yeung AK, Goldman RD (November 2005). "Use of steroids for erythema multiforme in children". Can Fam Physician. 51 (11): 1481–3. PMC 1479482. PMID 16353829.