Dermatology
Erythema Multiforme
다형홍반
Target lesions usually triggered by HSV infection
- How common
- Uncommon
- Typical age
- Ages 20–40
What is it?
Delayed hypersensitivity to HSV antigens → target lesions.
Commonly affected: Hands, arms, legs (acral)
How it develops
- HSV infectionPreceding cold sore or infection
- HSV antigen depositHSV DNA deposits in skin
- T-cell responseCD4 T-cell inflammation
- Target lesionThree-zoned target lesion
Symptoms
- Target lesionsThree concentric color zones
- Acral distributionHands, arms, legs predominant
- Mild mucosalEM major has mucosal involvement
How it is examined
- Visual examIdentify classic target lesions
Imaging
Clinical diagnosis.
- Clinical
Not needed.
- Clinical
Non-surgical care
- SymptomaticAntihistamines, NSAIDs
- Suppressive antiviralAcyclovir x 1 year for recurrent
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
None
Outlook
Most resolve spontaneously in 2–4 weeks.