Diagnosis

Bullous pemphigoid

Etiology

Cause [s9d]

• Autoimmune disease

• Triggers: furosemide, spironolactone, NSAIDs, captopril, penicillin, PD-1/PD-L1 inhibitors, gliptins, TNF-alpha inhibitors, ultraviolet irradiation, x-ray therapy, and vaccination

Pathophysiology [3ia][s9d]

1. IgG autoantibodies against adhesion complexes in the skin basement membrane

2. Antibodies --> complement activation and inflammatory mediators

3. Inflammatory cells release of proteolytic enzymes that damage the dermal-epidermal junction (hemidesmosomal proteins) and lead to blister formation

Complication

• Secondary infection due to multiple erosions and immunosuppressants

Epidemiology

Incidence per 100.000 [siv][kmc][mma]

Prevalence per 100.000 [siv][kmc][mma]

Approach

• Dermatoscopy

• Biopsy with immunofluorescence

• ELISA testing to detect antibodies [s9d]

Treatment

The goal of therapy: [rbr]

• Decrease blister formation

• Promote healing of blisters and erosions

• Determine the minimal dose of medication necessary to control the disease

Treatment depends on the severity of the disease: [s9d]

1. Topical super-potent steroids: <20% of body surface area in an elderly patient

2. Systemic immunosuppressive agents (corticosteroids + calcium/vitamin D/bisphosphonate)

Differential diagnoses

Acute intermittent porphyria, Dermatitis herpetiformis, Drug eruptions, Eczema, Epidermolysis bullosa, Erythema multiforme, Impetigo, Mastocytosis, Pemphigus vulgaris, Prurigo nodularis, Psoriasis, Scabies, Stevens-Johnson syndrome, Urticaria