What is the recommended management for bullae?

Management of Bullae

Determine the Underlying Etiology First

The management of bullae depends critically on distinguishing between autoimmune blistering disease (bullous pemphigoid) and infectious causes (necrotizing fasciitis), as these require fundamentally different and time-sensitive treatments. 1, 2

Clinical Assessment to Guide Management

For autoimmune bullous pemphigoid:

• Look for tense blisters on erythematous or normal-appearing skin of limbs and trunk in elderly patients (mean age ~80 years) 3
• Pruritus may precede bullae by weeks to months 3
• Associated with neurological disease (cerebrovascular disease, dementia, Parkinson's, epilepsy) 3
• Absence of systemic toxicity, pain disproportionate to findings, or rapid progression 2

For infectious causes with bullae:

• Critical warning signs include pain disproportionate to physical findings, violaceous bullae, cutaneous hemorrhage, skin sloughing, skin anesthesia, rapid progression, and gas in tissue 2
• Systemic toxicity: fever, tachycardia, hypotension 2
• Hemorrhagic bullae strongly suggest necrotizing fasciitis, most commonly from Vibrio species in appropriate exposure settings 4

Management Algorithm for Bullous Pemphigoid

First-Line Treatment

Superpotent topical corticosteroids (clobetasol propionate) are the first-line treatment, providing better disease control with significantly lower mortality compared to systemic corticosteroids. 1

For localized disease (<10% body surface area):

• Apply superpotent topical corticosteroids directly to lesions only 1, 5
• Escalate to systemic therapy if no improvement within 3-7 days 5

For generalized disease:

• Apply clobetasol propionate 20g per day (10g per day if weight <45kg) over entire body except face 1
• Increase to 40g per day if disease control not achieved within 1-3 weeks 1

Treatment Response and Tapering

• Assess response after 1-3 weeks; disease control = absence of new lesions or established lesions healing 1
• Begin tapering after 15 days once disease control achieved 1
• After 4 months, reduce to maintenance therapy of 10g once weekly applied to previously affected areas 1
• Continue maintenance for 8 months (total 12 months treatment duration) 1

Second-Line Treatment

If topical corticosteroids fail, use oral prednisone 0.5 mg/kg/day—never exceed 0.75 mg/kg/day due to significantly increased mortality risk in elderly patients. 1, 5

• Consider adjunctive azathioprine, which allows ~45% reduction in steroid dose 1
• Tetracyclines (tetracycline 500-2000 mg daily, doxycycline 200-300 mg daily, or minocycline 100-200 mg daily) combined with nicotinamide may be effective 1
• Avoid tetracycline in renal impairment and doxycycline/minocycline in hepatic impairment 1

Blister Care for Bullous Pemphigoid

• Small blisters should be left intact 1
• Large blisters should be punctured and drained with sterile needle, leaving blister roof in place as biological dressing 1, 2
• Apply bland emollients (50% white soft paraffin and 50% liquid paraffin) to support barrier function 2
• Non-adherent dressings for large erosions 2

Monitoring Schedule

• Every 2 weeks for first 3 months 1, 5
• Monthly for next 3 months 1, 5
• Every 2 months thereafter 1
• Monitor for skin atrophy, purpura, infections from topical steroids 1
• Relapse = ≥3 new lesions/month or extension of established lesions 1

Management Algorithm for Infectious Bullae

Immediate Actions

Hospitalize immediately for parenteral antibiotics and emergent surgical consultation if necrotizing fasciitis suspected—this is a surgical emergency. 2

• Obtain Gram stain and culture of pus/exudates 2
• Blood cultures if systemic symptoms present 2

Empiric Antibiotic Therapy

For suspected necrotizing fasciitis with bullae:

• Group A streptococcal/clostridial: clindamycin plus penicillin 2
• Polymicrobial: vancomycin plus piperacillin/tazobactam 2
• Vibrio vulnificus: doxycycline plus ceftazidime 2
• Aeromonas hydrophila: doxycycline plus ciprofloxacin 2

Blister Management for Infectious Causes

• Decompress intact bullae by piercing with sterile needle but leave blister roof in place 2
• Gently cleanse with antimicrobial solution before and after drainage 2
• Daily washing with antibacterial products to decrease colonization 2

Follow-up

• Reevaluate within 24-48 hours for outpatients to ensure appropriate response 2
• Consider burn unit admission for extensive skin involvement 2

Critical Pitfalls to Avoid

• Never use oral prednisone >0.75 mg/kg/day in bullous pemphigoid—associated with significant mortality in elderly patients 1, 5
• Do not delay surgical consultation for suspected necrotizing fasciitis—hemorrhagic bullae may occur in early stage 4
• Implement osteoporosis prevention when using systemic corticosteroids 1
• Discontinue minocycline if hyperpigmentation, pneumonia, or eosinophilia develop 1
• Positive DIF or BP180 ELISA >27 U/mL indicates increased relapse risk 1