Yes, skin warts can absolutely be flat—these are called plane warts or verruca plana.
Flat warts (verruca plana) are a well-recognized morphological subtype of cutaneous warts caused by human papillomavirus (HPV) infection, most commonly HPV types 3 or 10 1. They represent one of the four main anatomical/morphological categories of HPV-associated warts alongside common warts (verruca vulgaris), plantar warts (verruca plantaris), and genital warts 1.
Clinical Characteristics
Plane warts present as:
- Flat-topped papules that are skin-colored, pink, or brown
- Smooth surface with minimal elevation compared to common warts
- Typical locations: face, backs of hands, dorsal feet, arms, and legs 2, 3
- Multiple lesions often appearing in clusters
- Predominantly affect children and young adults, particularly on facial areas 3
Diagnostic Considerations
The diagnosis is usually clinical, though plane warts may need to be distinguished from:
- Lichen planus
- Thin actinic keratoses
- Seborrhoeic keratoses 1
Dermoscopy can aid diagnosis by revealing characteristic features such as dotted vessels 4.
Management Approach
For plane warts on the face or backs of hands, spontaneous clearance can often be awaited since these are mainly a cosmetic problem 1. This is particularly important because:
- Destructive and caustic agents are more likely to produce scarring at these sites and should be used with care 1
- Many plane warts will clear spontaneously, especially in children
When Treatment is Indicated:
First-line options 1:
- Salicylic acid cream/ointment 2-10% or cautious use of salicylic acid paint 12-17% without occlusion
- Cryotherapy with milder freeze (gentler than for common warts)
- Topical retinoid
Alternative treatments include:
- Imiquimod
- 5-fluorouracil cream
- Topical immunotherapy
- Photodynamic therapy (PDT)
- Various lasers (particularly for facial lesions) 5
Important Caveats:
- Avoid aggressive destructive methods on cosmetically sensitive areas like the face
- Treatment of filiform warts in the beard area should avoid damaging adjacent skin, as shaving can spread infection 1
- The evidence base for plane wart treatment is limited, with most recommendations based on clinical experience rather than robust trials 1
The key clinical principle is balancing treatment against the risk of scarring, particularly given that plane warts often resolve spontaneously and are primarily a cosmetic concern rather than a functional problem.