Condition- Erythema Multiforme

Question 1

What is erythema multiforme?

Answer 1

Inlammation of the skin and mucous membranes

Question 2

What type of hypersensitivity reaction causes Erythema multiforme?

Answer 2

Type 4 hypersensitivity reaction

Question 3

List some of the causes of Erythema multiforme

Answer 3

• Infectious:
  
  • viral: HSV
  • bacterial: mycoplasma, streptococcus
• Drugs:
  
  • Sulphonamides
• Inflammatory:
  
  • RhA, SLE, vascultidies
• Malignancy:
  
  • lymphoma
  • leukaemia
  • myeloma

Question 4

A patient presents with these lesions. What is the most likely underlying infectiou cause?

Answer 4

Erythema Multiforme

Herpes Simplex Virus

Question 5

Describe the presenation of patients with erythema multiforme…

Answer 5

• Prodrome of Fever, aches and URTI
• Lesion: 100s of itchy, red, burning papules => develop into raised plaques which have target like appearance. Central vesicle/crust
• Distribution: starts off on hands and feet => trunk

Question 6

What are the two classifications of Erythema Multiforme?

Answer 6

• EM Minor = skin
• EM Major = skin + mucosa

Question 7

Which investigations might you conduct on someone with Erythema Multiforme?

Answer 7

• Usually CLINICAL DIAGNOSIS
• Bloods: high WCC, eosinophilia, high ESR/CRP
• HSV serology, M pneumoniae titres
• CXR- sarcoidosis, pneumonia
• Skin biopsy if in doubt of diagnosis