Can bullous pemphigoid (BP) initially present with ecchymotic patches or subcutaneous hemorrhage that later evolve into hemorrhagic bullae?

Bullous Pemphigoid with Initial Ecchymotic Presentation

Yes, bullous pemphigoid can initially present with ecchymotic patches or subcutaneous hemorrhage that later evolve into hemorrhagic bullae, though this is considered an atypical presentation of the disease. 1

Clinical Presentation Variants of Bullous Pemphigoid

Bullous pemphigoid (BP) typically presents with:

• Classical form: Tense blisters on erythematous or normal-appearing skin, symmetrically distributed on flexural surfaces of limbs, inner thighs, and abdomen 1
• Prodromal phase: Pruritus alone or associated with erythema and/or urticarial plaques that may precede blister formation by weeks or months 1

However, atypical presentations can occur:

• Non-bullous forms (up to 20% of cases): Excoriations, prurigo-like lesions, eczematous lesions, urticarial lesions 1
• Localized variants: Dyshidrosiform (acral) lesions, erosions 1
• Ecchymotic/hemorrhagic variant: As observed in your patients, with subcutaneous hemorrhage or ecchymotic patches preceding the development of hemorrhagic bullae 2

Diagnostic Approach for Atypical Presentations

When encountering ecchymotic patches in elderly patients with suspected BP:

1. Histopathology: Biopsy from early lesions (including ecchymotic areas) should show:

   • Subepidermal clefting
   • Inflammatory infiltrate with eosinophils and/or neutrophils
   • Dermal infiltrate of eosinophils 1

2. Direct Immunofluorescence (DIF): Essential for diagnosis

   • Take biopsy from perilesional skin (1 cm away from lesion)
   • Look for linear deposits of IgG and/or C3 along the dermoepidermal junction 1

3. Serological Tests:

   • Indirect immunofluorescence on salt-split skin: IgG antibodies binding to epidermal side
   • ELISA for anti-BP180 and anti-BP230 antibodies 1

Management Considerations

For BP with ecchymotic presentation:

1. Initial treatment: Based on disease severity

   • Topical high-potency corticosteroids for localized disease
   • Systemic corticosteroids (prednisolone) for widespread disease 1

2. Adjuvant therapies:

   • Tetracyclines (doxycycline)
   • Azathioprine as steroid-sparing agent 1, 2

Important Considerations

• Age factor: BP predominantly affects elderly patients (>70 years), which aligns with your patients' demographics 1
• Comorbidities: Assess for neurological disorders (dementia, Parkinson's, cerebrovascular disease) which are associated with BP 1
• Medication review: Check for potential triggering drugs (diuretics, neuroleptics, gliptins) 1

Clinical Pearls and Pitfalls

• Diagnostic pitfall: Ecchymotic presentation may be misdiagnosed as:

  • Senile purpura
  • Vasculitis
  • Coagulopathy
  • Trauma-related bruising 2

• Clinical pearl: Maintain high suspicion for BP in elderly patients with unexplained pruritus and ecchymotic lesions, even without obvious bullae 3, 4

• Monitoring: BP180 ELISA titers may correlate with disease activity and can be used to monitor treatment response 1

The ecchymotic presentation you've observed represents an atypical but recognized variant of bullous pemphigoid. Prompt diagnosis through appropriate biopsy and immunofluorescence studies is crucial for initiating appropriate treatment and improving outcomes in these elderly patients.