Can verruca vulgaris (common wart) present with multiple lesions on the tibia, dorsum of the foot, and below the lateral malleolus, mimicking lichen planus, psoriasis, or eczema in a patient?

Verruca Vulgaris Can Present as Psoriasiform or Lichenoid Lesions on the Lower Extremities

Yes, verruca vulgaris can clinically and histologically mimic psoriasis, lichen planus, and eczema, particularly when presenting as verrucous or hyperkeratotic plaques on the lower extremities—this is a well-recognized diagnostic pitfall that requires careful clinicopathologic correlation.

Understanding the Clinical Mimicry

Verrucous Psoriasis: The Key Mimicker

Verrucous psoriasis is a distinctive variant that creates overlapping features with verruca vulgaris, making clinical and even histologic distinction challenging. 1

• This variant presents as flesh-colored to white mammillated plaques or coalesced papules, most commonly on knees (50%), elbows (33%), and dorsum of hands—exactly the distribution you're describing 1
• The lesions show papillomatosis with "buttressing" (bowing of peripheral rete ridges toward the center), which mimics the architecture of verruca vulgaris histologically 1
• This represents a patterned epithelial response to repeated trauma/irritation at these anatomic sites, explaining why lower extremity locations are particularly prone to this presentation 1

Why Your Biopsy Showed Verruca Vulgaris

The histologic distinction requires careful attention to specific features:

• True verruca vulgaris shows papillomatosis with buttressing, but lacks the regular psoriasiform hyperplasia and spongiform neutrophilic microabscesses typical of psoriasis 1
• Verruca vulgaris should show koilocytic change (which psoriasis lacks), though this may be subtle 1
• HPV immunostaining can definitively distinguish between the two when morphology is ambiguous 1

The Lichen Planus Connection

Regressing Verruca Can Mimic Lichen Planus

Verruca plana (flat warts) in their regressing phase exhibit lichenoid histological patterns that are frequently misdiagnosed as lichen planus or eczema. 2

Key features of regressing verruca that mimic lichen planus include:

• Superficial perivascular infiltration (96% of cases) 2
• Spongiosis and exocytosis (84%) 2
• Basal vacuolization (64%) 2
• Lichenoid infiltration (44%) 2
• These findings are more compatible with lichen planus or spongiotic eczema than classic verruca 2

Practical Diagnostic Algorithm for Your Case

Step 1: Confirm the Diagnosis

• Review the biopsy for HPV-specific features: koilocytic change, papillomatosis with specific architectural patterns 1
• Consider HPV immunostaining if not already performed, as this definitively confirms viral etiology 1
• Ensure PAS staining was negative to exclude fungal infection 1

Step 2: Assess Distribution Pattern

The location of your lesions (tibia, dorsum of foot, below lateral malleolus) is highly characteristic of:

• Mechanical trauma sites where verrucous changes develop 1
• Pressure points where both verruca and hyperkeratotic psoriasis preferentially occur 3

Step 3: Look for Distinguishing Clinical Features

Features favoring verruca vulgaris over psoriasis/lichen planus:

• Well-circumscribed, flesh-colored growths with white pebbly or papillary surface 4, 5
• Pinpoint bleeding (thrombosed capillaries) when pared—this is pathognomonic for warts and distinguishes them from corns, calluses, or psoriatic plaques 3
• Absence of silvery scale typical of psoriasis 6
• Lack of Wickham striae typical of lichen planus 7

Features favoring psoriasis:

• Indurated plaques with silvery scale 6
• Involvement of other classic psoriatic sites (scalp, elbows, knees bilaterally) 6
• Personal or family history of psoriasis 6

Management Implications

Treatment Approach for Confirmed Verruca Vulgaris

Complete surgical excision is the standard of care for HPV-associated lesions on the lower extremities, particularly when they persist and cause diagnostic confusion. 4

Alternative treatment options include:

• Cryotherapy, electrocautery, or laser ablation 4
• Observation for 2-3 weeks is only appropriate for small (<5mm), soft, stable lesions—your case with multiple established lesions requires definitive treatment 4

Critical Pitfall to Avoid

Do not treat empirically as psoriasis or lichen planus without confirming the diagnosis, as:

• Topical corticosteroids (first-line for psoriasis and lichen planus) will not eradicate HPV infection 7
• Immunosuppressive therapy could theoretically worsen viral proliferation 4
• The lesions may persist indefinitely without appropriate antiviral or ablative therapy 3

Special Considerations for Lower Extremity Location

Why This Location Matters

Plantar and lower extremity warts can persist for 5-10 years in adults with little inflammation, making them particularly prone to developing thick hyperkeratotic overlying changes that obscure the underlying viral etiology. 3

• The mechanical stress at these sites promotes both verrucous transformation of psoriasis and hyperkeratotic changes in warts 3, 1
• Flat feet (pes planus) increases pressure distribution abnormalities that exacerbate both conditions 3

Follow-Up Protocol

• Re-evaluate after treatment to ensure complete clearance 4
• Any recurrence or new lesions warrant repeat biopsy to exclude malignant transformation, though this is rare with common wart HPV types (2 and 4) 5
• Monitor for development of true psoriasis or lichen planus at other sites, as the initial clinical impression may have been partially correct if the patient has underlying predisposition 8