醫學筆記匯整 ED Notes

- Acute, self-limited, and sometimes recurring skin condition

- Type IV hypersensitivity reaction

- 所謂的 Target lesion, Bull eye sign

- 開始多在雙側四肢, 之後出現在 Trunk, 手掌腳掌也可有
  重要的是可能 involve mucus membrane

- 現在認為 EM 和 SJS/TEN :
   Separated as 2 distinct clinical disorders
   with similar mucosal reactions but different patterns of cutaneous lesions

 

• Erythema multiforme minor : 
   Typical targets or raised, edematous papules distributed acrally
   
• Erythema multiforme major :
   With involvement of one or more mucous membranes
   Epidermal detachment involves < 10% of total body surface area (TBSA)
  
   

1. The initial lesions are sharply demarcated,
   round, red/pink and flat (macules) 平
    
2. Which become raised (papules/palpable) 凸
    
3. And gradually enlarge to form plaques (flat raised patches) 
    
4. The centre of the papule/plaque darkens in colour
   and develops surface (epidermal) changes : blistering or crusting
   Lesions usually evolve over 72 hours.

• 中心 : 顏色深 with blister or crust
• 中間圈 : paler pink 淡粉紅 + raised due to oedema ( fluid swelling )
• 外圈 : bright red 鮮紅
  
   

    

不是標準三圈的叫做 Targetoid lesion !

 

• 最重要的是 Drug : 好像和 SJS 類的也差不多
   Antibiotics ( Sulphonamides, Penicillin)
   Anticonvulsants ( Phenytoin, Barbiturates)
   Aspirin
   Antituberculoids
   Allopurinol 
   
• Infection :
   最重要的是 Viral 中的 HSV1 
   Mycoplasma pneumoniae 也很常提到
   Post infectious reaction