What is a resistant wart called?

Resistant Warts: Terminology and Management

A resistant wart is called a recalcitrant wart, which refers to warts that persist despite standard treatments and may require specialized therapeutic approaches. 1

Characteristics of Recalcitrant Warts

Recalcitrant warts are characterized by:

• Persistence despite conventional treatments like salicylic acid and cryotherapy
• May be large, extensive, or present in difficult-to-treat locations
• Often occur in immunosuppressed patients
• May indicate underlying immune deficiency when unusually severe or prolonged 1

Factors Contributing to Treatment Resistance

Several factors can contribute to warts becoming recalcitrant:

• Location: Plantar warts have lower cure rates due to thicker cornified layer and poorer penetration of treatments 1
• Immune status: Immunosuppressed patients have higher rates of treatment resistance 1
• Duration: Longer-standing warts tend to be more resistant to treatment
• Type and size: Mosaic plantar warts are particularly challenging, with approximately 50% showing resistance to standard treatments 2

Management Algorithm for Recalcitrant Warts

First-Line Approaches

1. Salicylic acid (15-40%) applied daily after removing the thick keratin layer, with occlusion if possible, for 3-4 months 1, 3
2. Cryotherapy with liquid nitrogen every 2-3 weeks (not 4 weeks, which reduces efficacy) for 3-4 months 1, 3
3. Combination therapy: Using both salicylic acid and cryotherapy concurrently may be more effective than either treatment alone 1

Second-Line Approaches (for truly recalcitrant warts)

1. Injectable bleomycin (0.1-1 mg/mL solution): Particularly effective for periungual warts that have failed conventional treatments 3, 4

   • Requires local anesthesia
   • One to three treatments may be needed
   • Caution in patients >40 years, smokers, or those with lung/kidney disease

2. Surgical options: Curettage, electrocautery, or hyfrecation for filiform warts 1

   • Advantage of usually eliminating warts in a single visit
   • Requires local anesthesia
   • Risk of scarring if not performed properly

3. Photodynamic therapy: Applied after paring and/or salicylic acid pretreatment 3

   • Two to four treatments at 7-10 J/cm²
   • More suitable for facial and flat warts

Special Considerations by Wart Type

Plantar warts:

• More aggressive salicylic acid regimens (up to 40%)
• Careful paring before treatment application
• Avoid damaging surrounding skin to prevent spread 1

Facial/plane warts:

• Lower concentration salicylic acid (2-10%)
• Milder cryotherapy freezes
• Consider topical retinoids 1

Periungual warts:

• Consider bleomycin prick technique 4
• Alternative: cimetidine for pediatric patients with recalcitrant periungual warts 5

Important Clinical Pearls

• Treatment duration: Patience is essential as most treatments require several months for complete clearance 3
• Immunosuppression: Consider underlying immune deficiency when warts are unusually severe or prolonged 1
• Scarring risk: Balance aggressive treatment with risk of scarring, especially on visible areas 1
• Treatment intervals: For cryotherapy, 2-3 week intervals are significantly more effective than 4-week intervals (75% vs 40% cure rate) 2

Pitfalls to Avoid

• Overtreatment: Aggressive treatment can lead to scarring without improving efficacy
• Inadequate treatment duration: Most treatments require 3-4 months of consistent application
• Ignoring immune status: Unusually severe or prolonged warts should prompt consideration of underlying immune deficit 1
• Spreading infection: Avoid damaging surrounding skin during treatment, which can spread the virus 1

By following this structured approach to recalcitrant warts, clinicians can maximize treatment success while minimizing complications and patient discomfort.