1. Approach to Blistering Skin Conditions
Dr Wei Jing Loo
Assistant Professor
University of Western Ontario LHSC/ SJHC

2. Objectives  Competent in defining bulla & vesicle
 Demonstrate ability to describe blistering skin conditions
 Able to provide a list of differential diagnosis for blistering eruptions
 Demonstrate understanding of basic etiology/ pathogenesis of common blistering eruptions

3. Bulla • An elevated lesion that contains clear fluid
• A large blister ≥ 10 mm in diameter

4. Vesicle • An elevated lesion that contains clear fluid
• A small blister less than 10 mm in diameter

6. General approach
 History
 Examination  Investigations

7. History  Age  Previous medical history  Drug history
 Onset/ Duration of blisters  Associated symptoms

8. Examination
 Site/ distribution of blisters  Localised/ generalised  Associated systemic signs  Examine mucus membranes  Don’t forget SCALDA

9. Investigations  Blood work
 Skin scraping/ nail clipping  Allergy testing
 Skin biopsy

10. Causes of Blistering  Infection
 Inflammatory  Mechanical  Drug induced  Metabolic
 Autoimmune blistering diseases

11. Infection
 Bacteria
 Viral
 Fungal

12. Bullous impetigo

13. Chicken pox

14. Tinea pedis

15. Inflammatory  Acute eczema
 Contact dermatitis  Phototoxic reaction  Insect bite reaction

16. Dyshidrotic dermatitis

17. Acute bullous contact dermatitis

18. Phytophotodermatitis

19. Arthropod bites

20. Mechanical
 Friction
 Burns
 Cold injury

22. Friction blisters

23. Burns

24. Frost bite

25. Drug induced (will be covered in another lecture)
 Erythema multiforme
 Stevens-Johnson Syndrome
 Toxic Epidermal Necrolysis
(will be covered in another lecture)

26. Metabolic
 Porphyria cutanea tarda
 Diabetes

27. Porphyria

28. Bullous diabeticorum

29. Immunobullous disorders
 Bullous pemphigoid
 Pemphigus
 Dermatitis Herpetiformis

31. Bullous pemphigoid  Patients over 60 years old  Rarely in children
 No racial or ethnic predilection
 males = females

32. Histology – H&E

33. Bullous pemphigoid - IMM F

34. Bullous pemphigoid  Self limited  Good prognosis
 Remission after 5 to 6 years  May persist for > 10 years

35. Pemphigus Mediterranean descent.
 Mean age of onset 50 to 60 years old.
 Both sexes affected equally.
 Common in Jews/
Mediterranean descent.

36. Pemphigus

37. Pemphigus vulgaris

38. Histology – H&E

40. Pemphigus - IMM F

41. Bullous pemphigoid
Pemphigus

42. Pemphigus  Mortality rate 6%  Main cause of death – infection
 Immunosuppressives a contributing factor
 If patient survives >5 years after inception of disease, outcome is usually excellent

43. Dermatitis herpetiformis
 2nd to 4th decade of life
 2x as common in males
 Gluten sensitive
enteropathy
 Small bowel biopsy

44. Dermatitis herpetiformis
 Severe burning &
itching
 Precedes lesions 8 to
12 hours

46. Laboratory investigations
 Blood tests
 Antiendomysium antibodies  Tissue transglutaminase levels  Antireticulin antibodies  Antigliadin antibodies
 Skin biopsy + direct IMF

47. Dermatitis herpetiformis - treatment
 Sulfones
Dapsone
 Sulfapyridine
 Gluten free diet

48. Summary  Definition of bulla and vesicle
 Describe blistering skin eruptions
 Systematic approach to blistering skin conditions based on causes/ etiology