Approach to Blistering Skin Conditions

Dr Wei Jing Loo Assistant Professor

University of Western Ontario LHSC/ SJHC

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

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

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

General approach

History

Examination

Investigations

History

Age

Previous medical history

Drug history Onset/ Duration of blisters Associated symptoms

Examination

Site/ distribution of blisters

Localised/ generalised

Associated systemic signs

Examine mucus membranes

Don’t forget SCALDA

Investigations

Blood work

Skin scraping/ nail clipping

Allergy testing

Skin biopsy

Causes of Blistering

Infection

Inflammatory Mechanical Drug induced Metabolic

Autoimmune blistering diseases

Infection

Bacteria

Viral

Fungal

Bullous impetigo

Chicken pox

Tinea pedis

Inflammatory

Acute eczema

Contact dermatitis

Phototoxic reaction

Insect bite reaction

Dyshidrotic dermatitis

Acute bullous contact dermatitis

Phytophotodermatitis

Arthropod bites

Mechanical

Friction

Burns

Cold injury

Friction blisters

Burns

Frost bite

Drug induced

Erythema multiforme

Stevens-Johnson Syndrome

Toxic Epidermal Necrolysis

(will be covered in another lecture)

Metabolic

Porphyria cutanea tarda

Diabetes

Porphyria

Bullous diabeticorum

Immunobullous disorders

Bullous pemphigoid

Pemphigus

Dermatitis Herpetiformis

Bullous pemphigoid

Patients over 60 years old

Rarely in children

No racial or ethnic predilection

males = females

Histology – H&E

Bullous pemphigoid - IMM F

Bullous pemphigoid

Self limited

Good prognosis

Remission after 5 to 6 years

May persist for > 10 years

Pemphigus Mean age of onset 50 to 60 years old.

Both sexes affected equally.

Common in Jews/ Mediterranean descent.

Pemphigus

Pemphigus vulgaris

Histology – H&E

Pemphigus - IMM F

Bullous pemphigoid Pemphigus

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

Dermatitis herpetiformis

2nd to 4th decade of life

2x as common in males

Gluten sensitive enteropathy

Small bowel biopsy

Dermatitis herpetiformis

Severe burning & itching

Precedes lesions 8 to 12 hours

Laboratory investigations

Blood tests Antiendomysium antibodies

Tissue transglutaminase levels

Antireticulin antibodies

Antigliadin antibodies

Skin biopsy + direct IMF

Dermatitis herpetiformis - treatment

Sulfones Dapsone

Sulfapyridine

Gluten free diet

Summary

Definition of bulla and vesicle

Describe blistering skin eruptions

Systematic approach to blistering skin conditions based on causes/ etiology