Today we had an excellent outpatient case presentation by Dr. Chen. A patient presented with rash consistent with Erythema Multiforme. The rash was present on his palms.
Here are some quick take away points.
What is a quick differential and scenarios of a rash involving the palms (and soles)?
- Hand-foot-and-mouth disease (Coxsackie virus)
- papulovesicular lesions, oral lesions, in children or with exposure to children
- Rocky Mountain Spotted Fever (Rickettsia rickettsii)
- petechial, starting on wrist and ankles and spreading to the palms / soles / trunk
- remember outdoor exposure and geography! (south and eastern US)
- Secondary Syphilis (Treponema pallidum)
- maculopapular, also on face and trunk, if 6 months prior had painless chancre and / or has risk factors
- Disseminated Gonococcal infection
- pustular or vesiculopustular, dermatitis, migratory arthritis, and tenosynovitis, and / or has risk factors
- Erythema Multiforme (multiple etiologies)
- anular / targetoid lesions, pruritic
Others; Contact dermatitis, Kawasaki disease, Rubella, Scabies, Staphylococcal scalded skin syndrome, Stevens-Johnson syndrome, Toxic epidermal necrolysis, Toxic shock syndrome, HIV
What is Erythema Multiforme?
- acute, immune mediated condition
- round, erythematous macules which evolve into target lesions over 3-5 days, disappears in 2 weeks
- appears symmetrically on extremities, and may involve mucosa
90% of EM is due to infections
- HSV (HSV-1, HSV-2)
- Mycoplasma pneumoniae
Others; EBV, CMV, VZV, (many other viral and bacterial causes)
10% of EM is due to drugs
- Sulfonamides (TMP-SMX)
Others; Anticonvulsants, allopurinol, cephalosporins